UNITED STATES DISTRICT COURT FOR THE DISTRICT OF COLUMBIA

AGNIESZKA BOESEN and

CHRISTIAN BOESEN,

Plaintiffs,

v. Civ. Action No. 19-3499 (EGS) RONALD S. BROWN, DDS, MS,

et al.,

Defendants.

MEMORANDUM OPINION

I. Introduction

Plaintiffs Agnieszka Boesen (“Mrs. Boesen”) and Christian

Boesen (“Mr. Boesen”, and together with his wife “Plaintiffs”)

initiated this suit against Defendant Ronald S. Brown, DDS, MS,

(“Dr. Brown” or “Defendant”) for dental care that Dr. Brown

administered to Mrs. Boesen. Their medical malpractice claim

alleges that had Dr. Brown properly biopsied and diagnosed Mrs.

Boesen’s tongue lesion as tongue cancer in either August or

December of 2016, she would have avoided a neck dissection and

radiation therapy. Pending before the Court is Dr. Brown’s

Motion for Summary Judgment. See Def.’s Mot. Summ. J., ECF No.

1 41. 1 Upon careful consideration of the pending motion, the

opposition, the reply thereto, the applicable law, and the

entire record therein, the Court DENIES Dr. Brown’s Motion for

Summary Judgment.

II. Background

Mrs. Boesen began experiencing tongue irritation in early

2016. 2 Pls.’ Ex. 6 (“Boesen Dep.”), ECF No. 42-9 at 4. In

February, her dentist noted a “soft tissue lesion of the left

lateral border of the tongue” and suspected an allergic

reaction. Pls.’ Ex. 2, ECF No. 42-5 at 2. She followed up in May

when her symptoms reappeared and was referred to an oral surgery

doctor. Id.; Pls.’ Ex. 3, ECF No. 42-6 at 2. The oral surgery

doctor evaluated Mrs. Boesen in June and July and concluded that

her lesion was due to trauma or an autoimmune issue. Pls.’ Ex.

3, ECF No. 42-6 at 2. In mid-July, Mrs. Boesen was referred to

another doctor, who noted that the “left ventral side” of Mrs.

Boesen’s tongue was irritated, “has been a source of pain for

1 When citing electronic filings throughout this Opinion, the Court refers to the ECF page numbers, not the page numbers of the filed documents. 2 This factual background is based primarily on the parties’

statements of material facts, which are undisputed unless otherwise indicated. See Def.’s Statement of Material Facts Not in Dispute, ECF No. 41-3; Pls.’ Resp. Def.’s Statement of Material Facts Not in Dispute (“Pls.’ SOMF”), ECF No. 42-3; Def.’s Reply Counter-Statement Disputed Facts, ECF No. 43-2. Where necessary to provide adequate context, the Court includes other undisputed facts from the record. 2 about 7 months,” and despite visiting “several dentists and

physicians to treat this problem[,] . . . no one has offered a

definitive treatment plan.” Pls.’ Ex. 4, ECF No. 42-7 at 2. That

doctor suspected the irritation stemmed from a defective filling

on one of Mrs. Boesen’s teeth. Id. Mrs. Boesen had the tooth

extracted. Pls.’ Ex. 5 (“Brown Notes”), ECF No. 42-8 at 2.

After the extraction failed to alleviate her symptoms, Mrs.

Boesen consulted Dr. Brown at Georgetown Oral & Maxillofacial

Surgery. Id. On August 30, 2016, Dr. Brown examined Mrs. Boesen

and noted a “whitish plaque approximately 4 cm by 1 cm of the

left lateral/ventral border” of her tongue. 3 Id. at 3. He

performed a “punch biopsy” of the lesion in order to diagnose

the issue and “Rule-out Squamous Cell Carcinoma.” Id. The biopsy

was sent to LabCorp for analysis and returned a diagnosis of

“lichenoid mucositis” and stated that “differential diagnostic

possibilities include lichen planus and lichenoid drug

eruption.” Pls.’ Ex. 7, ECF No. 42-10 at 2. The report concluded

that “there is no evidence of high grade dysplasia,” which is a

pre-cancer. Id.

3 The parties dispute whether Mrs. Boesen’s lesion was also red in August. See Pls.’ Ex. 8 (“Brown Dep.”), ECF No. 42-11 at 109 (“The first time that I saw the lesion, it was a white lesion.”); Boesen Dep., ECF No. 42-9 at 4 (“I was pointing to my red lesion and telling him that that’s where I’d been hurting, and I’ve had all the discomfort for the last eight months.”). 3 Mrs. Boesen returned to Dr. Brown on December 15, 2016,

with the same complaint. He noted that this time she had an area

of “redness” on “the left lateral border of the tongue” and that

the results of the August biopsy “reported a histologic

diagnosis of lichenoid mucositis.” Brown Notes, ECF No. 42-8 at

6. Dr. Brown then officially diagnosed Mrs. Boesen with

“Licehenoid mucositis/Oral Lichen planus,” which is an

“autoimmune condition.” Id. at 6-7. He noted that while “Oral

Lichen Planus is not pre-malignant,” “there is an increased risk

of malignancy associated with the condition” and so “regular

follow-up visits are advocated.” Id. at 7. He concluded that a

“biopsy procedure may be indicated to confirm the diagnosis

although lichen planus can be diagnosed clinically by

experienced clinicians.” Id. at 8. He claimed that if a biopsy

is considered, “it is necessary for the surgeon to biopsy the

periphery of a lesion including some healthy tissue,” that “[i]t

is most helpful to include a white lesion rather than a red

lesion whenever possible,” and that “biopsy of a red lichenoid

lesion . . . is of limited diagnostic value.” Id. He provided

Mrs. Boesen with steroids to alleviate her symptoms. Id. at 6.

Five months later, Mrs. Boesen sought treatment from Dr.

Sciubba for a firm, eroded, painful lump on her tongue in the

same area where Dr. Brown treated her. Pls.’ Ex. 9, ECF No. 42-

12 at 2. Dr. Sciubba performed a biopsy, which returned a 4 diagnosis of “invasive squamous cell carcinoma.” Id. He then

referred her to head and neck surgeon Dr. Mydlarz for treatment.

Pls.’ SOMF, ECF No. 42-3 ¶ 23. On May 30, 2017, Dr. Mydlarz

performed a partial glossectomy to remove the lesion from Mrs.

Boesen’s tongue. Id. ¶ 5. The depth of invasion of the tumor was

5.7 mm and therefore Dr. Mydlarz recommended a neck dissection

to ensure the cancer had not spread to Mrs. Boesen’s lymph

nodes. Id. at ¶¶ 7, 9. Mrs. Boesen agreed; Dr. Mydlarz performed

the dissection, which confirmed that the cancer had not spread

to the lymph nodes. Id. ¶ 9. She also had post-operative

radiation because of the depth of invasion of the tumor. Id.

¶ 10.

In 2019, Mrs. Boesen and her husband 4 filed the current

medical malpractice suit against Dr. Brown. 5 Compl., ECF No. 1-1

at 4, 6. Discovery, including Rule 26(a)(2) Disclosures for

Expert Witnesses, concluded at the end of August 2021. Joint

Status Report, ECF No. 39 at 1. Dr. Brown moved for summary

judgment in October 2021. Def.’s Mem. P. & A. Supp. of Summ. J.

4 This suit also includes Mr. Boesen’s companion claim for loss of consortium, which is not at issue in this Motion for Summary Judgment. Compl., ECF No. 1-1 at 7. 5 The case was removed to this Court from the Superior Court of

the District of Columbia based on diversity jurisdiction. Notice of Removal, ECF No. 1 at 2-4. Plaintiffs’ suit initially included the laboratory that analyzed Mrs. Bosesen’s August 2016 biopsy as a defendant. Compl., ECF No. 1-1 at 4. However, the parties later stipulated to the dismissal of the lab as a defendant. Minute Order (Apr. 28, 2020). 5 (“Def.’s Mot.”), ECF No. 41-1. Plaintiffs submitted their

memorandum in opposition that November. Pls.’ Mem. P. & A. Opp.

Def.’s Mot. Summ. J. (“Pls.’ Opp.”), ECF No. 42-1. Dr. Brown

submitted his reply the following month. Def.’s Mem. P. & A.

Supp. Reply Pls.’ Resp. Opp. Mot. Summ. J. (“Def.’s Reply”), ECF

No. 43-1. The motion is now ready and ripe for adjudication.

III. Standard of Review

Federal Rule of Civil Procedure 56 requires the Court to

grant a motion for summary judgment when “there is no genuine

dispute as to any material fact and the movant is entitled to

judgment as a matter of law.” Fed R. Civ. P. 56(a). A “material”

fact is one that could “affect the outcome of the suit under the

governing law.” Anderson v. Liberty Lobby, Inc.,

(1986). And a dispute is “genuine” if “the evidence is such

that a reasonable jury could return a verdict for the nonmoving

party.”

The moving party bears the burden of “informing the

district court of the basis for its motion” as well as

“identifying those portions of the pleadings, depositions,

answers to interrogatories, and admissions on file, together

with the affidavits, if any, which it believes demonstrate the

absence of a genuine issue of material fact.” Celotex Corp. v.

Catrett,

(1986) (internal quotation marks

omitted); see also Fed. R. Civ. P. 56(c)(1)(A). To defeat 6 summary judgment, the nonmoving party must “designate specific

facts showing that there is a genuine issue [of material fact]

for trial.” Celotex Corp.,

(internal quotation

marks omitted). Either party “may object that the material cited

to support or dispute a fact cannot be presented in a form that

would be admissible in evidence.” Fed R. Civ. P. 56(c)(2).

In evaluating a summary judgment motion, “[t]he evidence of

the nonmovant is to be believed, and all justifiable inferences

are to be drawn in his favor.” Liberty Lobby,

.

The Court’s role at the summary judgment stage “is not . . . to

weigh the evidence and determine the truth of the matter but to

determine whether there is a genuine issue for trial.”

.

IV. Analysis

Under District of Columbia law, “[i]n a negligence action

predicated on medical malpractice, the plaintiff must carry a

tripartite burden, and establish: (1) the applicable standard of

care; (2) a deviation from that standard by the defendant; and

(3) a causal relationship between that deviation and the

plaintiff’s injury.” Washington v. Wash. Hosp. Ctr.,

(D.C. 1990). “Because these issues are distinctly

related to some science, profession, or occupation, expert

testimony is usually required to establish each of the elements,

except where the proof is so obvious as to lie within the ken of

7 the average lay juror.”

(internal quotation marks and

citations omitted).

In moving for summary judgment, Defendant offers three

arguments, all concerning the opinions of Plaintiffs’ sole

expert witness, Dr. Mark L. Bernstein (“Dr. Bernstein”). First,

Defendant argues that Dr. Bernstein “cannot provide the

admissible evidence needed by Plaintiffs to establish the

element of causation.” Def.’s Mot., ECF No. 41-1 at 9. Second,

Defendant claims that “Plaintiffs have not demonstrated the

existence of any causation evidence that is related to the

December 15th appointment.” Def.’s Reply, ECF No. 43-1 at 12.

And finally, Defendant argues that Plaintiffs fail to provide

any evidence “that Dr. Brown breached the standards of care when

he provided treatment to Ms. Boesen” on either August 30 or

December 15. Id. at 6-9. Since a court ruling on a motion for

summary judgment can only consider admissible evidence, the

Court begins by determining whether Dr. Bernstein’s expert

testimony on causation is admissible.

A. Admissibility of Dr. Bernstein’s Expert Opinion

Although state law determines when expert testimony is

required in a negligence action, Federal Rule of Evidence 702

governs the admissibility of such evidence. See Burke v. Air

Serv Int’l, Inc.,

(D.C. Cir. 2012). It

states:

8 A witness who is qualified as an expert by knowledge, skill, experience, training or education may testify in the form of an opinion or otherwise if: (a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; (b) the testimony is based on sufficient facts or data; (c) the testimony is the product of reliable principles and methods; and (d) the expert has reliably applied the principles and methods to the facts of the case. Fed R. Evid. 702. Under Rule 702, trial judges serve as

gatekeepers to ensure that the methodology underlying the expert

testimony is valid and the expert’s conclusions are based on

“good grounds.” Daubert v. Merrell Dow Pharm., Inc.,

(1993). A district court has “broad discretion in

determining whether to admit or exclude expert testimony.”

United States ex rel. Miller v. Bill Harbert Int’l Constr.,

Inc.,

(D.C. Cir. 2010) (internal quotation

marks omitted).

As Plaintiffs note in their brief, see Pls.’ Opp., ECF No.

42-1 at 15; challenges to expert testimony are usually brought

in a motion in limine or ”Daubert motion” during pretrial

proceedings. See Sloan v. Urban Title Servs., Inc.,

, 238 (D.D.C. 2011) (“The proper vehicle for raising

[challenges to a proposed expert’s qualifications] is a motion

in limine filed in the context of pretrial proceedings and, if

necessary, the Court shall consider a request that a Daubert

9 hearing be held to evaluate [the expert’s] proffered

testimony.”).

In this district, when such challenges are brought within

motions for summary judgment, judges have “expressed concern”

over the “premature” nature of the motion, urging that “‘the

Daubert regime should be employed only with great care and

circumspection at the summary judgment stage.’” Carmichael v.

West, No. 12-1969,

, at *7 (D.D.C. Aug. 31,

2015) (quoting Cortés-Irizarry v. Corporación Insular de

Seguros,

(1st Cir. 1997)). This caution

reflects concerns that “‘except when defects are obvious on the

face of a proffer,’” courts may “‘exclude debatable scientific

evidence without affording the proponent of the evidence

adequate opportunity to defend its admissibility.’”

(quoting

Cortés-Irizarry,

). Overall, the decision whether

to “conduct the reliability and helpfulness analysis that

Daubert and Rule 702 require in the context of a summary

judgment motion” and ultimately “to exclude expert testimony

found wanting from its consideration in ruling on the [summary

judgment] motion” is within the discretion of the court.

(internal quotation marks omitted); see also Landmark Health

Sols., LLC v. Not for Profit Hosp. Corp.,

(D.D.C. 2013) (“Trial courts are afforded substantial

latitude in deciding the procedure necessary to test the 10 sufficiency of a potential expert . . . .” (internal quotation

marks omitted)).

In this case, most of Defendant’s briefing concerns the

admissibility of Dr. Bernstein’s testimony. See generally Def.’s

Mot., ECF No. 41-1; Def.’s Reply, ECF No. 43-1. Accordingly,

both parties have fully examined the issues and Plaintiffs have

been given adequate opportunity to defend admissibility. The

Court will therefore conduct the Daubert and Rule 702 analysis,

keeping in mind the broader context of summary judgment. See

Arsanjani v. United States, No. 19-1746,

, at *3

(deciding to “weigh the Rule 702 factors as [the Court] normally

would” because the “experts have had ample opportunity to defend

their reports in depositions appended to the briefing here” and

the Court did not “find their testimony to be on a subject so

overly scientific or complex that an additional hearing would

alter the admissibility analysis”).

Defendant’s admissibility arguments are confined to Dr.

Bernstein’s causation opinions. In Plaintiffs’ brief, they

summarize that opinion as “had the standard of care been met by

Dr. Brown, more likely than not, a precancerous diagnosis would

have been made and Mrs. Boesen would not have undergone the

treatment that she ultimately did.” Pls.’ Opp., ECF No. 42-1 at

16; see also Pls.’ Ex. 13 (“Bernstein Report”), ECF No. 42-16 at

11 4 (“It is within a reasonable degree of probability that a

premalignant condition (dysplasia) or superficial carcinoma was

present at the time that Dr. Brown did his biopsy [in August

2016]. . . . In my opinion, within a reasonable degree of

medical probability, had Dr. Brown’s initial biopsy shown the

true nature of the disease, excisional surgery could have been

performed 5 months earlier, preventing the need for neck

dissection and radiation.”). Defendant argues that Dr. Bernstein

was “unable to provide the testimony needed to demonstrate that

[his causation] opinions are reliable or that . . . he is

properly qualified to render them.” Def.’s Mot., ECF No. 41-1 at

10. The Court takes each of these arguments in turn.

1. Reliability

In challenging reliability, Defendant questions both Dr.

Bernstein’s methods and the sufficiency of the facts and data

underlying his causation opinions. See Def.’s Mot., ECF No. 41-1

at 14 (claiming that Dr. Bernstein “is unable to present any

methodology for rendering [his] opinion”); id. at 18 (listing

all the details Dr. Bernstein “does not know” about the

formation of Mrs. Boesen’s cancer).

Courts have substantial “latitude [both] in deciding how to

test an expert’s reliability” and in deciding “whether that

expert’s relevant testimony is reliable.” Kumho Tire Co. v.

Carmichael,

(1999). In conducting the inquiry, 12 a court must focus solely on “principles and methodology, not on

the conclusions that they generate.” Meister v. Med. Eng’g

Corp.,

(D.C. Cir. 2001) (quoting Daubert,

). When evaluating methodology for scientific

validity, a court may consider where relevant: “(1) whether the

theory or technique can be and has been tested; (2) whether the

theory or technique has been subjected to peer review and

publication; (3) the method’s known or potential rate of error;

and (4) whether the theory or technique finds general acceptance

in the relevant scientific community.” Ambrosini v. Labarraque,

(D.C. Cir. 1996). If an expert is “relying

solely or primarily on experience, then the witness must explain

how that experience leads to the conclusion reached, why that

experience is a sufficient basis for the opinion, and how that

experience is reliably applied to the facts.” Fed. R. Evid. 702

advisory committee’s note.

A court should not exclude testimony that “merely

represent[s] a weak factual basis,” which is “appropriately

challenged on cross examination.” Heller v. District of

Columbia,

(D.D.C. 2013); see also

Daubert,

(“Vigorous cross examination,

presentation of contrary evidence, and careful instruction on

the burden of proof are the traditional and appropriate means of

attacking shaky but admissible evidence.”). Rather, the court’s 13 gatekeeping role is to exclude expert “opinion evidence that is

connected to existing data only by the ipse dixit of the

expert,” that is, when “there is simply too great an analytical

gap between the data and the opinion proffered.” Gen. Elec. Co.

v. Joiner,

(1997).

Beginning with methodology, Defendant claims that Dr.

Bernstein is “unable to present any methodology for rendering

[his causation] opinion and when asked about his personal

experience to render it testified that it ‘can’t be vetted in

science.’” Def.’s Mot., ECF No. 41-1 at 14. Defendant then

concludes that because there is “no methodology to challenge,”

Def.’s Reply, ECF No. 43-1 at 16; Dr. Bernstein’s opinions are

“ipse dixit,”

and “amount to nothing more than pure

conjecture and speculation on his part and are completely

unreliable,” Def.’s Mot., ECF No. 41-1 at 14.

Plaintiffs respond that “Dr. Bernstein’s education,

training, and experience” form the basis of his causation

opinions. Pls.’ Opp., ECF No. 42-1 at 19. And that he conducted

his analysis by “look[ing] at all the facts, apply[ing] the

facts to the medical knowledge of the relevant field; and

formulat[ing] an opinion,” which is “exactly what a medical

expert witness is to do in such a case where the claim of

14 negligence is the defendant’s failure to gather the appropriate

information at the appropriate time.” Id. at 22.

Based on a thorough analysis of the record, the Court

agrees with Plaintiffs. When asked the basis for his opinion

that Mrs. Boesen had dysplasia in August 2016, Dr. Bernstein

responded, “[m]y experience, my education[,] and training.”

Pls.’ Ex. 14 (“Bernstein Dep.”), ECF No. 42-17 at 152. When

probed for specifics, Dr. Bernstein replied that he could render

an opinion about when Mrs. Boesen first developed dysplasia

because he’s “seen cancers evolve from dysplasias.” Id. He then

explained that “medicine and dentistry has always been an

applied science,” id. at 153; that his opinion was based on his

“knowledge of how cancer evolves,” id. at 154; and that it

“can’t be vetted in pure science” because he has a “lack of

absolute scientific proof” regarding the formation of Mrs.

Boesen’s dysplasia, id. at 152. However, he definitively stated

that “[i]t is my opinion that in August . . . based upon my

experience, based upon all the patients that I’ve seen in 35

years, based upon what I’ve read, that this lesion was probably

at least dysplasia at that [time] in August. And then more

likely than that, because it evolves, in December.” Id. at 150-

51. Based on the full context of this testimony, Dr. Bernstein’s

equivocations relate only to being unable to definitively prove,

“in pure science,” that Mrs. Boesen had dysplasia at a certain 15 time. This concern speaks to the degree of confidence Dr.

Bernstein has in his conclusions, 6 not the methodology he

employed in generating them. In making his argument, Defendant

omits the word “pure” from Dr. Bernstein’s quote to claim that

Dr. Bernstein is actually commenting on his methodology, as one

that “can’t be vetted in science,” Def.’s Mot., ECF No. 41-1 at

14. The Court rejects this distortion of the record as a reason

to discredit Dr. Bernstein’s causation opinions.

Furthermore, Dr. Bernstein’s testimony establishes that his

opinions are sufficiently grounded in his experience, education,

and training to satisfy Daubert and Rule 702. His qualifications

include “teaching of pathology and oral pathology to . . .

dental students and . . . residents,” Bernstein Dep., ECF No.

42-17 at 18; “see[ing] clinical patients . . . [for] 45 years of

6 To establish a prima facie case for negligence claims for medical malpractice in D.C., a Plaintiff must prove each element by a “preponderance of the evidence.” Rhodes v. United States,

(D.D.C. 2013) (citing District of Columbia v. Price,

(D.C. 2000)). Expert opinions on causation must establish to “‘a reasonable degree of medical certainty, that the defendant’s negligence is more likely than anything else to have been the cause (or a cause) of the plaintiff’s injuries.’”

at 303 (quoting Giordano v. Sherwood,

(D.C. 2009)). “[A]bsolute certainty is not required . . . .” Sponaugle v. Pre-Term, Inc.,

(D.C. 1980). Since Dr. Bernstein’s equivocations are about absolute certainty, as opposed to “a reasonable degree of medical certainty,” the Court also rejects Defendant’s claim that Dr. Bernstein “concedes that he cannot render [his opinions] to a reasonable degree of dental certainty.” Def.’s Mot., ECF No. 41-1 at 14. 16 . . . practice at the dental school,” id. at 44; “doing

research, [to] keep[] up with . . . [his] responsibilities as an

educator,” id. at 33; going to “two pathology meetings each

year, and one forensics meeting each year,” id. at 37; and

“writ[ing] the board examinations in oral pathology

that . . . students take,” id. at 78. When asked about research

“[i]n this case, for purposes of rendering opinions,” Dr.

Bernstein replied that he reviewed “articles that [he] wrote”

and “textbooks” to see “if they addressed this particular

problem,” id. a 45; and then proceeded to list the names of

several publications and the page numbers he consulted. 7 Id. at

7 Plaintiffs cite these publications and Dr. Bernstein’s qualifications in their brief, see Pls.’ Opp., ECF No. 42-1 at 20-22. Defendant in his reply brief claims that Dr. Bernstein’s “curriculum vitae and the information contained in it are hearsay and not supported by affidavit or other admissible evidence.” Def.’s Reply, ECF No. 43-1 at 12. He also “objects to the statements from Dr. Bernstein’s curriculum vitae,” id. at 13 n.2; and “objects to the publications that Plaintiffs cite,” id. at 13 n.3. The Court notes that Plaintiffs are not attempting to bolster Dr. Bernstein’s testimony with additional information, but rather Plaintiffs are drawing the Court’s attention to the publications and qualifications that Dr. Bernstein testified to in the same deposition that Defendant quotes at length in his briefs. See Pls.’ Opp., ECF No. 42-1 at 20 (stating that Dr. Bernstein discussed the publications “at the outset of his deposition”); id. at 22 (citing where in Dr. Bernstein’s deposition he discussed each qualification). For this reason, the Court does not agree that such information is not admissible evidence. Furthermore, to the extent Defendant argues that “Dr. Bernstein’s testimony directly contradicts the argument that Plaintiffs attempt to make about those publications,” Def.’s Reply, ECF No. 43-1 at 13; inconsistencies in testimony are the purview of cross-examination, going to the weight of the 17 46-50. Dr. Bernstein also noted that he “reviewed . . . [the]

medical records” in this case as well as the depositions of Dr.

Brown and Mrs. Boesen. Id. at 67-68.

In connecting his training to his opinions in this case,

Dr. Bernstein referenced the articles and materials he consulted

while giving his opinions. For example, discussing the relevance

of the color of Mrs. Boesen’s lesion, Dr. Bernstein testified

that “being red is always more scary than being white. The

articles that I . . . gave to you for review will explain that.”

Id. at 113. He also stated that “[a] white lesion . . . on the

tongue has a 25 percent chance statistically of being

premalignant or malignant. Dysplasia or cancer. That will be

seen in one of the reports that I gave you.” Id. at 148. In

discussing Mrs. Boesen’s case specifically, he noted that “it

was a single isolated lesion, a red and white lesion in a high-

risk area for oral cancer” and thus he did not share Dr. Brown’s

conclusion that the lesion was “lichen planus.” Id. at 116.

These examples, alongside the list of publications Dr. Bernstein

discussed in his testimony, indicate that he both possessed and

utilized his expertise in oral pathology to evaluate the facts

of Mrs. Boesen’s case and render an opinion. Discussing and then

applying established medical knowledge to the facts of a

testimony and not its admissibility. See Daubert,

. 18 specific case is a common practice for rendering an expert

opinion. See West v. Bayer HealthCare Pharm. Inc.,

(D.D.C. 2018) (“Plaintiffs’ experts are infectious

disease doctors who have applied their education, experience and

knowledge of infectious diseases to the information available to

them about a patient and, based on that information, have chosen

what they believe is the most likely cause of that patient’s

illness over all other possibilities. This type of medical

diagnosis—while obviously not infallible—is a reliable,

scientific manner of generating an expert opinion.”). Thus, the

Court does not agree that Dr. Bernstein was “unable to present

any methodology for rendering an opinion,” Def.’s Mot., ECF No.

41-1 at 14. See Arsanjani,

, at *6 (“an expert

need not employ a rigorous analytical methodology if the expert

is instead qualified on the basis of his or her practical

experience or training” (internal quotation marks omitted)).

Often intertwined with his argument about methodology,

Defendant challenges the reliability of Dr. Bernstein’s opinions

by pointing to all the information Dr. Bernstein “does not

know.” Def.’s Mot., ECF No. 41-1 at 18. Since Rule 702 requires

that expert testimony be “based on sufficient facts or data,”

Fed. R. Evid. 702(b), the Court addresses this argument as a

separate challenge to Dr. Bernstein’s testimony on the grounds

that he was without sufficient facts or data to render his 19 opinion. See Def.’s Reply, ECF No. 43-1 at 11-12 (claiming that

an admitted lack of knowledge about the doubling rate of Mrs.

Boesen’s cancer is “an admission by Plaintiffs that Dr.

Bernstein is without the ‘data’ he needs to render a causation

opinion about the December 15th appointment”).

Essentially, Defendant argues that Dr. Bernstein is not

able to claim that “had dysplasia or a less invasive carcinoma

been diagnosed 5 months earlier[,] Ms. Boesen would likely have

been able to avoid the neck dissection and radiation and might

have needed less tongue surgery,” because he “does not know when

the cancer first formed, how fast it grew, [and] when it reached

a point when it required a neck dissection or radiation

therapy.” Def.’s Mot., ECF No. 41-1 at 18 (internal quotation

marks omitted). Plaintiffs respond that they are “not obligated

to prove absolute certainty in this case,” Pls.’ Opp., ECF No.

42-1 at 22; and that “[t]he evidentiary standard that must be

met in this matter is not on what specific date did the

dysplasia or cancer form; [but] rather, . . . as a result of the

violations of the standard of care, more likely than not and

within a reasonable degree of medical certainty, what damages

occurred,” id. at 17.

The Court again agrees with Plaintiffs. Beginning with Dr.

Bernstein’s opinion that Mrs. Boesen had dysplasia on her first

20 visit to Dr. Brown, Defendant implies that knowing when the

lesion began to be precancerous is a prerequisite to forming

such an opinion. Certainly, if Dr. Bernstein knew the moment the

cancer formed or even how fast it grew, this would provide a

strong basis for his opinion—perhaps even certainty—that Mrs.

Boesen had dysplasia when Dr. Brown examined her in either

August or December 2016. But such knowledge is not necessary to

form that opinion or to render that opinion admissible. See

West,

(“Where two highly experienced and

knowledgeable infectious disease doctors opine about the most

likely bacterial cause of a patient’s infectious disease based

on all of the facts surrounding his history and clinical

presentation, those opinions are not subject to exclusion simply

because they are not also confirmed by tests that definitively

prove the presence of that bacteria.” (emphasis added)). Rather,

those facts, would only strengthen (or undermine) Dr.

Bernstein’s opinion. And thus, they go to the weight of his

opinion instead of its admissibility.

As Dr. Bernstein noted in his testimony, “cancers grow” and

they “start[] to evolve quickly after a certain point” when the

“doubling rate starts to have a visible effect.” Bernstein Dep.,

ECF No. 42-17 at 157-58. He further noted that Mrs. Boesen’s

“isolated red-and-white lesion, getting larger, not responding

to treatment” was such a visual indication of potential 21 pathology.

. And that therefore “[a]t the time that

the lesion was symptomatic and evolving, there is a darn good

chance that it was at least dysplasia.”

. These

markers, although certainly not definitive scientific proof that

Mrs. Boesen had dysplasia when she was examined by Dr. Brown,

are sufficient to sustain Dr. Bernstein’s opinion. They

establish that Mrs. Boesen was presenting symptoms of pathology

on her tongue when she first saw Dr. Brown and that because

those symptoms did not abate with time or treatment dysplasia

was likely the underlying cause. Although the data does not

definitively prove Dr. Brown’s opinions, the Court cannot

conclude that there is “too great an analytical gap between the

data and the opinion proffered.” See Mendes-Silva v. United

States,

(D.C. Cir. 1993) (holding that an

expert witness “acknowledging that no scientific evidence exists

which conclusively establishes [a] causal link” is not a “bar to

the admissibility of . . . expert opinion on causation”).

Defendant also argues that Dr. Bernstein cannot render

reliable causation testimony about the subsequent treatment Mrs.

Boesen received because he was “unable to provide an answer [to]

any questions about when Ms. Boesen needed to have a neck

dissection and radiation therapy.” Def.’s Mot., ECF No. 41-1 at

17. The Court disagrees. First, this statement is belied by the

record. Dr. Bernstein explained that at a “certain thickness of 22 invasion” of the tumor on the tongue, “it is statistically best

to do a lymph node [or neck] dissection.” Bernstein Dep., ECF

No. 42-17 at 158. He also testified that the range of such

invasion is “about three to five millimeters in thickness,”

which is a “boilerplate” range that is “in the textbooks of oral

pathology.” Id. at 159-60. Dr. Bernstein then read from and

provided a citation to a textbook that supported his claim. Id.

at 161-63. Second, the parties agree that at the time the tumor

was extracted in May 2017, “the depth of invasion of the tumor

was 5.7 [mm].” Pls.’ SOMF, ECF No. 43-2 ¶ 7. This depth of

invasion alongside the earlier testimony that Mrs. Boesen’s

lesion exhibited markers of dysplasia during both her visits to

Dr. Brown suffice as “sufficient facts or data” to underlie Dr.

Bernstein’s opinion that an earlier diagnosis of the cancer by

Dr. Brown would have allowed Mrs. Boesen to avoid neck surgery.

Thus, the Court disagrees with Defendant’s claim that Dr.

Bernstein’s causation opinions are “ipse dixit,” Def.’s Reply,

ECF No. 43-1 at 16; or “nothing more than pure conjecture and

speculation on his part,” Def.’s Mot., ECF No. 41-1 at 14.

2. Qualifications

Rule 702 allows an expert witness to be qualified by their

“knowledge, skill, experience, training, or education.” Fed R.

Evid. 702. A court qualifying an expert witness must conclude

23 that the proposed expert possesses “a reliable basis in the

knowledge and experience of [the relevant] discipline.” Daubert,

. Judges in this circuit have noted that “[w]hile

a person who holds a graduate degree typically qualifies as an

expert in his or her field, such formal education is not

required.” Rothe Dev., Inc. v. Dep’t of Def.,

(D.D.C. 2015) (internal quotation marks and citation

omitted). Furthermore, “[c]onclusory statements that an expert

is qualified because of his education or experience is

insufficient for a court to find that the witness is indeed

qualified to offer his expert opinion.” Arias v. DynCorp,

(D.D.C. 2013).

Although Defendant claims throughout his briefs that Dr.

Bernstein is “not qualified” to render the proffered opinions,

Defendant does not dispute Dr. Bernstein’s credentials. Rather,

solely challenging Dr. Bernstein’s opinion regarding causation,

Defendant points to the fact that Dr. Bernstein is not “trained

to perform glossectomies,” does not “perform radiation,” and

that “with regard to the neck dissection and when that’s

indicated . . . the surgeons make that ultimate decision.”

Def.’s Mot., ECF No. 41-1 at 17-18.

In the context of Dr. Bernstein’s extensive credentials and

the exact details of his causation opinion, the Court does not

24 agree that Dr. Bernstein is not qualified to render his

causation opinions. Dr. Bernstein’s causation opinion was

summarized in Plaintiffs briefs as: “had the standard of care

been met by Dr. Brown, more likely than not, a precancerous

diagnosis would have been made and Mrs. Boesen would not have

undergone the treatment that she ultimately did.” Pls.’ Opp.,

ECF No. 42-1 at 16. It is undisputed that Mrs. Boesen’s

treatment included a partial glossectomy, neck dissection, and

radiation. See Pls.’ SOMF, ECF No. 42-3 ¶¶ 5, 6, 10. Experience

in performing the treatment Mrs. Boesen ultimately received is

not a prerequisite for forming an opinion about when that

treatment is necessary.

Dr. Bernstein’s opinion is limited to claiming that a

misdiagnosis—stemming from an error in Dr. Brown’s performance

of the biopsy in August 2016, see Bernstein Dep., ECF No. 42-17

at 116 (“the misconception of red versus white biopsy, that’s

the area where I think is the . . . issue”) and his subsequent

failure in December to perform a second biopsy, see

(“That

would have been an instant biopsy, a re-biopsy.”)—caused

subsequent treatment. Dr. Bernstein has extensive credentials to

qualify him to render this conclusion. First, as noted above,

Dr. Bernstein has been teaching oral pathology and seeing

clinical patients, specifically for oral pathology and “oral

lesions,” for decades.

. His patients often come 25 with “concerns that [a pathology] could be cancer.”

.

Second, Dr. Bernstein also teaches a class on “[w]hen it’s

appropriate to do a biopsy,” “[h]ow much tissue,” and “[w]hat

they do with the biopsy once they actually cut the biopsy out.”

. Third, as noted above, the decision to “do the neck

dissection” is based on “a certain thickness of invasion” and

that standard is “boilerplate” at 3-5 mm of invasion.

. And finally, Dr. Bernstein testified that about half of

his patients “have continued problems with dysplasia or follow-

up for cancer.”

. Therefore, Dr. Bernstein has

extensive experience with performing biopsies on oral lesions

and diagnosing oral lesions as benign, cancerous, or

precancerous dysplasia. And while he may not “make the ultimate

decision” for when a neck dissection is warranted, his

experience with patients who have continued problems with

dysplasia and oral cancer establish that he is familiar with the

treatments of those pathologies even if he does not perform such

treatments himself. Furthermore, from his teaching experience,

Dr. Bernstein is familiar enough with typical treatments for

oral cancer to know when a certain thickness of invasion will

warrant a neck dissection. Thus, the Court concludes that Dr.

Bernstein is qualified to render his causation opinions.

Overall, the Court rejects Defendant’s claim that he is

entitled to summary judgment because Plaintiffs’ expert witness 26 Dr. Bernstein “cannot provide the admissible evidence needed by

Plaintiffs to establish the element of causation for a prima

facie claim of dental malpractice,” Def.’s Mot., ECF No. 41-1 at

9.

B. Sufficiency of Causation Evidence

In his reply brief, Defendant claims for the first time

that Plaintiffs do not provide “legally sufficient evidence to

demonstrate the element of causation for a prima facie case of

dental malpractice” for Mrs. Boesen’s December appointment with

Dr. Brown. Def.’s Reply, ECF No. 43-1 at 11. Defendant claims

that Dr. Bernstein’s testimony fails to meet the requirements

for “legally sufficient” evidence because it: (1) “does not even

mention that appointment or the care that Dr. Brown rendered at

it”; (2) “is not an opinion that is ‘based on a reasonable

degree of medical certainty’”; and (3) “does not state that it

is Dr. Bernstein’s opinion that the treatment that Dr. Brown

provided to Ms. Boesen on that date is more likely than anything

else, the cause (or a cause) of her alleged injuries.”

This argument is analytically distinct from Defendant’s

previous argument regarding the admissibility of Dr. Bernstein’s

causation testimony. Although both focus on the element of

causation, this new argument claims that even if Dr. Bernstein’s

testimony were admissible, it fails to establish the element of

27 causation as a matter of law. See Arsanjani,

, at

*3 (explaining that one Defendant sought summary judgment by

challenging the “admissibility of expert testimony” while

another Defendant “presse[d] an alternative route to judgment,”

claiming that “even if admissible, [the expert’s] report and

testimony would be insufficient as a matter of law” to establish

an element of the prima facie case).

“[I]t is well established that district courts need not—

and, indeed, generally should not—consider arguments raised for

the first time in a reply brief.” Pauling v. District of

Columbia, No. 13-0943,

, at *2 (D.D.C. June 15,

2015); see also Benton v. Laborers’ Joint Training Fund,

(D.D.C. 2015) (citing cases). The prudential

concerns behind this practice are that: (1) considering such

arguments “would be manifestly unfair” to the opposing party who

“has no opportunity for a written response” and (2) “it would

risk the possibility of an improvident or ill-advised opinion,

given our dependence as an Article III court on the adversarial

process for sharpening the issues for decision.” Herbert v.

Nat’l Acad. of Scis.,

(D.C. Cir. 1992)

(internal quotation marks omitted).

Defendant’s argument about the sufficiency of causation

evidence implicates these twin concerns. Nothing in Defendant’s

28 opening brief would put Plaintiffs on notice that they must show

precisely where in the record Dr. Bernstein stated his December

15 causation opinions, his belief that his opinion was “based on

a reasonable degree of medical certainty,” or that he believed

Dr. Brown’s negligence was, “more likely than anything else,”

the cause of Mrs. Boesen’s injuries. Plaintiffs’ brief focused

on the admissibility of Dr. Bernstein’s testimony—his

methodology and credentials—and did not include the extraneous

information Defendant now seeks in its challenge. See Pls.’

Opp., ECF No. 42-1 at 19-24. Furthermore, although the Court is

likely familiar enough with Dr. Bernstein’s testimony to rule on

this argument, it is reluctant to do so without Plaintiffs’

input on the legal issues in order to avoid “an improvident or

ill-advised opinion.”

Therefore, the Court declines to consider Defendant’s

argument about the legal sufficiency of Plaintiffs’ causation

evidence regarding Mrs. Boesen’s December appointment with Dr.

Brown.

C. Sufficiency of Standard of Care Evidence

Similarly, Defendant claims for the first time in his reply

brief that Plaintiffs failed to provide expert opinion testimony

that Dr. Brown breached the standards of care in either August

or December. Def.’s Reply, ECF No. 43-1 at 6, 8. For the August

29 appointment, Defendant claims that Dr. Bernstein does not “ever

state that it is his opinion that . . . Dr. Brown breached the

standards of care on August 30th” because “it is not an opinion

that he holds in this case.” Id. at 6. For the December

appointment, Defendant claims that Dr. Bernstein’s testimony

about the standard of care is not “legally sufficient” because

he is “expressing his personal opinion about what he would have

done, not an opinion about what was required by the national

standards of care.” Id. at 8. Although Defendant attempts to

stylize this claim as a failure of “causation evidence,” id. at

7, 9; the arguments are in substance a challenge to the

sufficiency of evidence for a separate element of Plaintiffs’

malpractice claim—breach of the standard of care—and thus are

new arguments first raised in Defendant’s reply brief.

Although, as noted above, district courts usually do not

address arguments first raised in reply briefs, the prudential

concerns underlying that general rule are not implicated for

these claims. First, although Plaintiffs in their brief noted

that the “standard of care is unchallenged,” they nevertheless

offered evidence in the record that substantiated their claims

on the standard of care because they found it “important for the

Court to recognize the full bread of the testimony.” Pls.’ Opp.,

ECF No. 42-1 at 14. Because Plaintiffs have submitted their view

30 of the sufficiency of the standard of care evidence, considering

Defendant’s arguments would not be “manifestly unfair.”

Second, although Defendant claims to be making, in part, an

argument about the “legal sufficiency” of the evidence proffered

on the standard of care, his claim boils down to a factual

dispute about what evidence is or is not in the record. For

example, relating to the August appointment, Defendant is not

disputing Dr. Bernstein’s familiarity with the standard of care

or what that standard is. Rather, Defendant is challenging

whether there is any evidence in the record that Dr. Bernstein

holds the opinion that Dr. Brown breached the standard in

August. Thus, the Court does not conclude that a ruling on such

narrow, factual claims would provide an “improvident or ill-

advised opinion.” The Court will therefore address Defendant’s

arguments regarding the standard of care.

1. August Appointment

Defendant first claims that Plaintiffs cannot provide

“expert opinion testimony to establish that Dr. Brown breached

the standards of care on August 30th” because that opinion is

“not an opinion that [Dr. Bernstein] holds in this case.” Def.’s

Reply, ECF No. 43-1 at 6-7. To substantiate his argument,

Defendant quotes from Dr. Bernstein’s testimony. When asked,

“[c]an we agree, Doctor, based on the information that you know

and that you’re aware of at this point in time, that you are

31 without sufficient information to render the opinion that on

August 30th Dr. Brown breached the standard of care with respect

to the treatment that he provided and the biopsy he took of Ms.

Boesen,” Dr. Bernstein responded, “I cannot render an opinion

based upon my speculation. I can’t tell you what he saw.” Id. at

7 (quoting Bernstein Dep., ECF No. 47-12 at 119-20).

Plaintiffs in their brief claim that Dr. Bernstein’s report

and testimony conclude that “in a patient such as Mrs. Boesen

who presents with a lesion of both a red and white component,

the standard of care required that the red component be

biopsied” and Dr. Brown did not conduct that biopsy. Pls.’ Opp.,

ECF No. 42-1 at 14.

Looking at the record as a whole, the Court again agrees

with Plaintiffs. In Dr. Bernstein’s report, he states that Dr.

Brown “should have known that the red area [of Mrs. Boesen’s

lesion] was more likely to show these diagnostic changes than

the white area, yet [Dr. Brown] specifically avoided the best

representative site for the cancer to be found.” Bernstein

Report, ECF No. 42-16 at 4. In his deposition, Dr. Bernstein

elaborates on this conclusion and states that Dr. Brown’s

“misconception of red versus white biopsy, that’s the area where

I think is the . . . issue.” Bernstein Dep., ECF No. 42-17 at

116. He explains, “if you think it’s lichen planus and you want

to make the case for lichen planus, you take a white component.

32 And if you want to rule out cancer, you get the red component.

Ergo, you take both. You take a piece that contains both red and

white.” Id. at 127. He later restates this opinion:

[Y]ou’re not taking a biopsy to prove it’s lichen planus. You’re taking a biopsy to find out what it is and to rule out cancer. And if your objective is to rule out cancer, you need to take a red lesion. If all you care about is lichen planus, then you take a white lesion for such, and you take that red lesion to rule out the possibility of a dysplasia or cancer. Because [Mrs. Boesen] had nothing in her . . . mouth that even resembled lichen planus clinically.

Id. at 140. He also noted that Dr. Brown did not take a biopsy

of the red component and even “sent [Mrs. Boesen] a letter that

said he would not biopsy a red component;” thus, Mrs. Boesen

“was not going to get the biopsy she needed from him.” Id. at

135 (emphasis added). Applying summary judgment standards and

taking all reasonable inferences in Plaintiff’s favor, this

testimony is sufficient to show that Dr. Bernstein believed Dr.

Brown deviated from the standard of care in August 2016 by

failing to perform a biopsy on the red portion of Mrs. Boesen’s

lesion.

Defendant’s argument fails to persuade the Court otherwise.

Although the quoted portions from Defendant’s brief are accurate

representations of Dr. Bernstein’s testimony, they do not

undermine the Court’s conclusion that Dr. Bernstein holds the

opinion that Dr. Brown breached the standard of care in August.

33 When Dr. Bernstein stated, “I cannot render an opinion based

upon my speculation. I can’t tell you what he saw,” Bernstein

Dep., ECF No. 42-17 at 122; this response was in the context of

Defendant’s counsel repeatedly asking Dr. Bernstein whether he

“still h[e]ld the opinion that on August 30th, the lesion that

Dr. Brown saw, the four-by-one centimeter lesion was red and

white,” id. at 117-18. Dr. Bernstein repeatedly stated that he

didn’t know and “will never know . . . what [Dr. Brown] saw at

that time.” Id. at 118. Defendant’s counsel then, over the

objection of Plaintiffs’ counsel, concluded that Dr. Bernstein’s

opinion “is not an opinion that [he could] render without

engaging in speculation,” and Dr. Bernstein replied again, “I do

not know what Dr. Brown saw.” Id. at 119. The Federal Rules of

Evidence do not require experts to testify from personal

knowledge. See Fed. R. Evid. 602. Thus, Dr. Bernstein’s lack of

knowledge of the color of Mrs. Boesen’s lesion in August is not

fatal to his opinion testimony and Defendant is not entitled to

summary judgment on this ground.

2. December Appointment

Defendant claims that Dr. Bernstein’s testimony “does not

establish legally sufficient evidence that Dr. Brown breached

the standards of care when he provided treatment to Ms. Boesen

on December 15th” because his statement “makes clear, that he is

expressing his personal opinion about what he would have done,

34 not an opinion about what was required by the national standards

of care.” Def.’s Reply, ECF No. 43-1 at 8. Looking at the record

as a whole, the Court again disagrees.

First, in Defendant’s own statement of facts, he claims

that “Dr. Bernstein stated in his deposition that the standard

of care required a biopsy be taken on December 15, 2016,” citing

to the portion of Dr. Bernstein’s testimony that Defendant now

challenges. Pls.’ SOMF, ECF No. 42-3 ¶ 46. While this portion of

the record indeed includes Dr. Bernstein’s statement that “to

me—well, that’s a mandatory biopsy,” Bernstein Dep., ECF No. 42-

17 at 122; other portions of Dr. Bernstein’s testimony confirm

that he is speaking about an established national standard

rather than a personal one. Earlier in his testimony, Dr.

Bernstein states: “I have a rule that says you have a lesion

that does not go away after you’ve tried to treat it—it’s not my

rule. This is the rule. Okay? This is—this is a maxim in oral

pathology. You have a mucosal lesion that doesn’t go away after

you’ve tried to treat it in a couple of weeks, it gets

biopsied.” Id. at 111 (emphases added). Furthermore, Dr.

Bernstein testified that, applying this rule to Mrs. Boesen’s

case in December, after the lesion “is not getting any better

with the steroid treatment” prescribed by Dr. Brown in August,

“[t]hat would have been an instant biopsy, a re-biopsy.” Id. at

115-16. Thus, Dr. Bernstein’s testimony in full context 35 establishes that he believes Dr. Brown violated an established

standard—as he put it, “a maxim in oral pathology”—when Dr.

Brown did not re-biopsy Mrs. Boesen’s lesion. Therefore, taking

the evidence as a whole and rendering all reasonable inferences

in Plaintiffs’ favor, the Court does not conclude that Dr.

Bernstein’s testimony spoke only to his own, personal standards.

Because Defendant has failed to establish as a matter of

law that Plaintiffs’ evidence on a breach of the standard of

care in either August or December is insufficient, the Court

declines to grant summary judgment on this ground.

V. Conclusion

For the foregoing reasons, the Court DENIES Defendant’s

Motion for Summary Judgment, see ECF No. 41.

An appropriate Order accompanies this Memorandum Opinion.

SO ORDERED.

Signed: Emmet G. Sullivan United States District Judge November 14, 2023

36