                   United States Court of Appeals
                         FOR THE EIGHTH CIRCUIT
                                   ___________

                                   No. 03-2554
                                   ___________

Robert E. Mattke; Sherry Mattke,         *
                                         *
             Plaintiffs - Appellants,    *
                                         *
      v.                                 *
                                         *
Claude Deschamps, M.D.,                  *
individually and in his professional     *
capacity; Clayton Cowl, M.D.,             * Appeal from the United States
individually and in his professional     * District Court for the
capacity,                                 * District of Minnesota.
                                         *
             Defendants,                 *
                                         *
Mayo Clinic, Rochester; The Mayo         *
Foundation,                              *
                                         *
             Defendants - Appellees.     *
                                     __________

                           Submitted: March 8, 2004
                              Filed: July 8, 2004
                               ___________

Before WOLLMAN, MORRIS SHEPPARD ARNOLD, and COLLOTON, Circuit
      Judges.
                         ___________

COLLOTON, Circuit Judge.
       Robert and Sherry Mattke appeal two decisions of the district court1 in this
diversity case arising out of alleged medical negligence. First, the Mattkes appeal the
district court's adverse grant of judgment as a matter of law on their claim based on
the doctrine of res ipsa loquitur. Second, they appeal the district court's jury
instruction prohibiting the jury from basing a finding of negligence on the actions of
Mayo Clinic's pathology department. We affirm.

                                           I.

       Appellant Robert Mattke was referred to Mayo Clinic in Rochester, Minnesota,
by his family physician after he had been coughing up blood for several months. Mr.
Mattke had been a heavy smoker for fifty years, until quitting in 1992. He had also
been exposed to asbestos. A CT scan performed on October 26, 1999, at Mayo Clinic
revealed a mass in the upper lobe of Mr. Mattke's right lung. A Mayo Clinic
physician performed a biopsy of the lung two days later, and tissue samples collected
during the biopsy were reviewed by two Mayo pathologists. Both pathologists
diagnosed Mr. Mattke with adenocarcinoma of the lung, a form of cancer. Based on
Mr. Mattke's medical history and the pathology report, a team of Mayo Clinic doctors
recommended that Mr. Mattke undergo surgery to remove the mass. Mr. Mattke
agreed, and on November 1, 1999, a surgeon removed the upper right lobe of Mr.
Mattke's lung. Extensive tests performed on the removed section of lung indicated
that Mr. Mattke did not, in fact, have cancer. Rather, Mr. Mattke's lung contained an
abscess caused by infection, a non-emergent condition that could have been treated
without surgery.

      Mr. Mattke and his wife brought a diversity action in the district court, alleging
claims based on medical malpractice, res ipsa loquitur, respondeat superior, and loss


      1
      The Honorable Richard H. Kyle, United States District Judge for the District
of Minnesota.

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of consortium. The Mattkes did not bring claims based on a breach of warranty or
guarantee, or negligent non-disclosure of risk. At trial, appellees Mayo Clinic and
Mayo Foundation (collectively "Mayo Clinic" or "Mayo") presented evidence that the
misdiagnosis of Mr. Mattke's tissue samples occurred because of a phenomenon
known as cellular floaters. Mayo's evidence indicated that this phenomenon occurs
when cells from one patient become mixed with tissues samples of another patient
during the processing of the tissue samples in the pathology laboratory.

       Evidence presented to the jury by Mayo indicated that cellular floaters are a
rare but "inevitable" occurrence in modern pathology laboratories. A study by the
College of American Pathologists showed that floaters occur on approximately one
out of every 100 slides, but are rarely problematic, because the floaters generally are
of a different tissue type than the cells under examination. For example, muscle cells
appearing on a brain tissue biopsy slide often are easily distinguished by a
pathologist. On one out of 1,000 slides -- ten percent of slides with floaters -- the
contaminant cells will be cancerous. The evidence presented showed that on six out
of 100,000 slides, these cancerous floater cells will be "mimics," that is, cells that are
of the same tissue type as the biopsy tissue. Mayo Clinic presented evidence that
these cancerous "mimics" cannot be detected or prevented, and can cause errors in
diagnosis.

       The district court granted Mayo's motion for judgment as a matter of law on the
Mattkes' res ipsa loquitur claim, finding that the Mattkes had failed to present
evidence that cellular floaters generally do not occur absent negligence. The district
court also instructed the jury that conduct of the Mayo pathologists could not form
the basis for a determination that Mayo Clinic was negligent, because no standard of
care, or a departure from such standard, had been established with respect to the
pathology department. Because this is a diversity suit, we apply the substantive law
of the forum state, which is Minnesota. Erie R.R. v. Tompkins, 304 U.S. 64, 78
(1938).

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                                           II.

                                           A.

       On appeal, the Mattkes claim that the district court erred in granting Mayo's
motion for judgment as a matter of law on the Mattkes' res ipsa loquitur claim. "We
review a district court's grant of judgment as a matter of law de novo, applying the
same standard as the district court." Anderson v. Independent Sch. Dist., 357 F.3d
806, 809 (8th Cir. 2004). Judgment as a matter of law is appropriate when "a party
has been fully heard on an issue and there is no legally sufficient evidentiary basis for
a reasonable jury to find for the party on that issue." Fed.R.Civ.P. 50(a). We draw
all reasonable inferences in favor of the non-moving party, and do not make
credibility determinations or weigh the evidence. Reeves v. Sanderson Plumbing
Prod., Inc., 530 U.S. 133, 150 (2000).

        Res ipsa loquitur is a Latin phrase meaning "[t]he thing or situation speaks for
itself." Hestbeck v. Hennepin County, 212 N.W.2d 361, 365 (Minn. 1973). Under
Minnesota law, a plaintiff wishing to submit a res ipsa loquitur claim to a jury needs
to prove three things: "(1) that ordinarily the injury would not occur in the absence
of negligence; (2) that the cause of the injury was in the exclusive control of the
defendant; and (3) that the injury was not due to plaintiff's conduct." Hoven v. Rice
Mem'l Hosp., 396 N.W.2d 569, 572 (Minn. 1986). A plaintiff must present evidence
supporting application of the doctrine before a jury may be instructed on res ipsa
loquitor. Weiby v. Wente, 264 N.W.2d 624, 629 (Minn. 1978); see also Hoven, 396
N.W.2d at 571-72 (where plaintiff did not present evidence that his nerve injury did
not normally occur absent negligence, trial court properly refused to submit res ipsa
loquitur claim to jury).

     Expert medical testimony is not necessary to support a res ipsa loquitur claim
where "the matters to be proved fall within an area of common knowledge and

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developing lay comprehension of medical techniques and where the results of
surgical or medical treatment, viewed in the light of all the circumstances, provide a
sufficient evidentiary basis to support an inference of negligence." Hestbeck, 212
N.W.2d at 364. The district court found that "[t]his case, which involves the internal
workings of the pathology lab, clearly falls outside" an area of common knowledge.
(Tr. 417). The court further found that the Mattkes had failed to present evidence
from which a jury reasonably could conclude that what happened in Mayo Clinic's
pathology laboratory must have been caused by negligence. We agree with the
district court.

       At trial, a pathologist with Mayo Clinic testified that cellular floaters cannot
be prevented and can cause diagnostic error. He testified that he believed Mr. Mattke
was misdiagnosed because of this unpreventable phenomenon. Because the Mattkes
did not present any evidence contradicting Mayo Clinic's cellular floater evidence,
the uncontroverted evidence at trial was that cellular floaters are not preventable and
can cause diagnostic error. In other words, the Mattkes presented no evidence that
cellular floaters ordinarily do not occur in the absence of negligence. As the district
court noted, "the evidence before the Court indicates only the reverse." (Tr. 417).

        Without expert testimony indicating that cellular floaters normally do not occur
without negligence, the Mattkes' claim of res ipsa loquitur should have been
submitted to the jury only if it involved "an area of common knowledge and
developing lay comprehension." Hestbeck, 212 N.W.2d at 364. It did not. This is
not the type of situation that has been held to be within an "area of common
knowledge" by the Minnesota Supreme Court. In fact, that court has held specifically
that a claim involving pathological diagnosis "is distinctly not the kind of case where
the negligence 'speaks for itself' without expert medical opinion, such as where a
surgeon leaves a sponge in the body or where there is unexplained injury to a healthy
part of the body remote from the treatment area." Todd v. Eitel Hosp., 237 N.W.2d
357, 361 (Minn. 1975); see also Hestbeck, 212 N.W.2d at 364; Schulz v. Feigal, 142

                                          -5-
N.W.2d 84, 88-89 (Minn. 1966) (claim based on res ipsa loquitur appropriate where
physician mistakenly injected patient's heart with adrenalin); Warrick v. Giron, 290
N.W.2d 166, 169 (Minn. 1980) (res ipsa loquitur did not apply because "the
injury-producing event involves complex questions of the effect of certain medical
treatments on a patient suffering from nerve and muscle disorders not completely
understood by the medical profession itself"). Accordingly, the district court did not
err in granting Mayo's motion for judgment as a matter of law on this claim.

                                           B.

       The Mattkes also claim that the district court erred by instructing the jury that
the conduct of the doctors in the Mayo Clinic pathology department could not form
a basis for finding that Mayo was negligent in the diagnosis, care, or treatment of Mr.
Mattke. District courts have broad discretion in formulating jury instructions, and we
review the instructions for an abuse of discretion. Lighting & Power Servs., Inc. v.
Roberts, 354 F.3d 817, 819 (8th Cir. 2004). "Our review is limited to determining
whether the instructions, when taken as a whole and in light of the particular issues
presented, fairly and adequately presented the evidence and the applicable law to a
jury." Id. Because this is a diversity case, Minnesota law applies to the substance of
the instructions, while federal law controls our review of the district court's discretion
in refusing or admitting the instructions. Bennett v. Hidden Valley Golf and Ski, Inc.,
318 F.3d 868, 873 (8th Cir. 2003).

       Minnesota law requires a plaintiff to establish four elements in a medical
malpractice claim: (1) "the standard of care recognized by the medical community as
applicable to the particular defendant's conduct;" (2) a departure from that standard;
(3) that the defendant's departure from the standard of care was a direct cause of the
plaintiff's injuries; and (4) damages. Tousignant v. St. Louis County, 615 N.W.2d 53,
59 (Minn. 2000). The first two of these elements generally must be established
through the testimony of expert witnesses. See, e.g., id. at 58; Hestbeck, 212 N.W.2d

                                           -6-
at 364. This is because "most medical malpractice cases involve complex issues of
science or technology, requiring expert testimony to assist the jury in determining
liability." Tousignant, 615 N.W.2d at 58.

       Under Minnesota law, a physician who is to give an expert opinion about the
quality of care given by a defendant doctor must "make a substantial showing of
qualification in the particular field of inquiry." Swanson v. Chatterton, 160 N.W.2d
662, 669 (Minn. 1968); see also Teffeteller v. Univ. of Minn., 645 N.W.2d 420, 427
(Minn. 2002). It is generally required that expert physician witnesses have an
understanding of what would usually and customarily be done by a doctor in a
situation similar to that confronted by the defendant physician. Lundgren v.
Eustermann, 370 N.W.2d 877, 880 (Minn. 1985). The Mattkes, however, did not
present expert testimony regarding either the appropriate standard of care for the
pathology department, or a departure from such a standard.

       Dr. Donald Burrows, the Mattkes' only expert witness, testified that he was not
a pathologist, though he had contacts with pathologists and pathology laboratories in
the course of his duties as a physician. Dr. Burrows' primary areas of practice are
sleep disorders and pulmonology. He had never heard of the phenomenon of cellular
floaters until he began work on this case. He further testified that he was not familiar
with the cellular floaters study introduced by Mayo Clinic, did not know how often
cellular floaters occurred, and did not know what measures modern pathology
laboratories take to avoid floaters. We do not believe, therefore, that Dr. Burrows
could be considered an expert under Minnesota law for purposes of commenting on
the actions of Mayo Clinic's pathology department or the phenomenon of cellular
floaters. See Swanson, 160 N.W.2d at 666-69 (holding trial court properly excluded
testimony of internist who testified regarding fractures, because expert was not an
orthopedist, and did not have experience treating fractures like the one at issue in the
case). And even assuming arguendo that Dr. Burrows could qualify as such an



                                          -7-
expert, his testimony did not set forth a standard of care or a departure from such
standard by the Mayo pathology department.

        The Mattkes argue that testimony at trial by Mayo Clinic's witnesses
established a standard of care. Assuming that this is the case, all of Mayo's witnesses
testified that no malpractice occurred. Since Dr. Burrows was the Mattkes' only
expert witness, no expert called by either the Mattkes or Mayo Clinic testified as to
a breach of a standard of care by the Mayo pathology department. In order to prove
medical negligence in a malpractice action, a plaintiff "must offer expert medical
testimony both to state the standard of medical care and the treatment recognized by
the medical community and to establish that the defendant physician in fact departed
from that standard[.]" Silver v. Redleaf, 194 N.W.2d 271, 272 (Minn. 1972)
(emphasis added); see also Sorenson v. St. Paul Ramsey Med. Ctr., 457 N.W.2d 188,
190 (Minn. 1990); Shea v. Esensten, 622 N.W.2d 130, 135 (Minn. Ct. App. 2001).

      The exception to this rule is that "expert testimony is not necessary where the
matters to be proved fall within an area of common knowledge and developing lay
comprehension of medical techniques . . . ." Hestbeck, 212 N.W.2d at 364. As
discussed above in the context of appellants' res ipsa loquitur claim, we do not
believe that this is a situation falling into such an area. This conclusion is especially
strong in light of Dr. Burrows' testimony that he was not familiar with the
phenomenon of cellular floaters prior to the trial. If a licensed and practicing
physician is not aware of a particular medical phenomenon, we cannot expect it to be
something with which a reasonable layperson would be familiar. The actions of the
pathology department here involve facts that would not be within "an area of common
knowledge and developing lay comprehension of medical techniques." Hestbeck, 212
N.W.2d at 364. Minnesota law therefore requires that expert testimony be presented
regarding a departure from an established standard of care before a negligence claim
based on the actions of Mayo Clinic's pathology laboratory could be considered by



                                          -8-
the jury. There was no such evidence, and the district court's jury instructions were
a correct statement of Minnesota law in light of the evidence in this case.

      For the foregoing reasons, the judgment of the district court is affirmed.
                    _____________________________




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