Expert Review of Histologic Slides and Papanicolaou Tests in the Context of Litigation or Potential Litigation

Abstract

Review of histologic sections and cytologic smears is often a key component of civil litigation in cases of alleged negligence or medical malpractice. While the outcome of such cases may hinge on the testimony of expert witnesses, determining who is qualified to serve as an expert in such cases is generally left to the court. The Board of Governors of the College of American Pathologists has adopted separate statements for review of histologic slides and Papanicolaou (Pap) tests that outline some of the issues that should be considered in this context. These guidelines were developed in an effort to ensure accuracy and fairness in expert testimony when histologic or cytologic slides are reviewed as part of litigation.Departure from the standard of care in the practice of medicine is defined as conduct that falls below that which a reasonable physician would practice under similar circumstances. Finding a deviation from the standard of care in surgical pathology is in sharp contrast to a difference of opinion, which may not represent an error on the part of the original pathologist. When histologic slides are reviewed in the context of litigation, several issues must be considered before determining whether the standard of practice has been met or whether negligence has occurred. Such issues include the following:The following guidelines have been prepared by the College of American Pathologists to help ensure accuracy and fairness in expert testimony when histologic slides are reviewed for reasons of litigation, potential litigation, or disciplinary action.1. Individuals performing slide review in the context of litigation must have significant experience examining and reporting the disease and type of specimen under consideration. Those lacking such experience are not qualified to render an expert opinion on whether the original pathologist met the standard of care. Instead, the court should rely on the testimony of expert witnesses who have, at a minimum, the following qualifications:2. The standard of care should be that of a reasonable and prudent practitioner following normal practices at the time the original diagnosis was rendered. Finding a deviation from the standard of care requires showing that the diagnosis was inappropriate based on examination of the original slides and clinical information that was available to the pathologist. This finding should not be based on clinical outcome or subsequent changes in diagnostic criteria.3. To reduce the effect of hindsight bias, histologic slide review should be done without knowledge of clinical outcomes or the specifics of the claim. Disclosing a subsequent recurrence, metastasis, or other significant development to the reviewing expert witness before he or she has reviewed the slides introduces the possibility of bias into the review.4. Review should occur in an environment that, as closely as possible, approaches a normal practice environment. This may be in the reviewing pathologist's own office or laboratory, but can occur in other settings.5. When slides are reviewed for the purposes of litigation or the determination of negligence, the same slides that were the basis for the original interpretation must be the subject of the review.6. Fair and impartial review of histologic slides must not discriminate between defendant and plaintiff.7. Compensation of the physician-witness should reasonably reflect the time and effort expended by the witness in preparation, depositions, and trial. Compensation of a physician-witness must not be contingent on the outcome of the trial, as this introduces the possibility of bias and the appearance of possible impropriety.The Pap test is the most effective cancer screening test in medical history and remains the most effective screening method for the identification of premalignant cervicovaginal conditions. The Pap smear has been associated with a 70% to 80% decrease in the death rate from cervical cancer in the United States.If the Pap test is to continue as an effective cancer screening procedure, it must remain widely accessible and reasonably priced for all women, including those who are economically disadvantaged and at high risk for cervical cancer. There must also be an understanding of the inherent limitations of this procedure.The Pap test is a screening test that involves subjective interpretation by a cytotechnologist or pathologist of the 50 000 to 100 000 cells that are present on a typical Pap smear. Experience indicates an irreducible false-negative rate of at least 5%. Although rescreening can reduce the false-negative rate, zero-error performance can never be attained. Many factors, including the subjectivity involved in diagnosing difficult cases and sampling problems with specimen collection, prevent zero-error performance.The following guidelines should be used for review of Pap tests for litigation or potential litigation.1. The finding of a false-negative smear is not necessarily evidence of practice below the standard of care. The decision as to whether a false-negative smear is the result of negligence should be made not only on the basis of the individual result, but also in the context of the laboratory's overall performance on Pap tests.2. Atypical cells of undetermined significance represent a poorly defined diagnosis with poor interobserver and intraobserver reproducibility. Therefore, disputed cases of atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance are not likely to represent reasonable grounds for allegations of practice below the standard of care.3. Papanicolaou test slides being assessed for possible litigation should be reviewed without knowledge of clinical outcome and in an environment that simulates the normal screening practice as closely as possible. This may be accomplished through an unbiased screening review process that includes the contested case as one of a number of normal and abnormal Pap smears representing a variety of disease states. Review with knowledge of subsequent development of carcinoma biases the objectivity of the review and does not reflect standard practice.4. The standard of care should be that of the reasonable and prudent practitioner. Courts should recognize that a false-negative result is not sufficient proof of negligence. Rather, the courts should look to whether the overall Pap test practices of the laboratory meet the standard of care.5. Professional expert witnesses who do not have significant experience in cytopathology are not qualified to express an expert opinion on the standard of care. Instead, a court should rely on the testimony of expert physician-witnesses that have, at a minimum, the following qualifications:6. Compensation of the physician-witness should reasonably reflect the time and effort expended by the witness in preparation, depositions, and trial. Compensation of a physician-witness contingent on the outcome of the case introduces the possibility of bias and should not be permitted.7. The state should adopt a mechanism by which nonbinding arbitration would be required prior to the filing of any civil action alleging negligence in the taking, examining, or reviewing of a Pap test or the reporting of its results. The nonbinding arbitration mechanism should include the following features:If the state does not adopt such a plan, the parties should strongly consider mediation or nonbinding arbitration by a panel of individuals trained and having experience in cytopathology before proceeding with civil litigation relating to a Pap test.The usefulness of the Pap test guidelines in actual litigation has been demonstrated on numerous occasions in the 2 to 3 years since they were adopted by the College. Their credibility has been further strengthened by the adoption of similar guidelines with minor modifications by the American Society of Cytopathology,1 the American Society for Cytotechnology,2 and by more than 30 state pathology societies. Of particular significance has been the acknowledgment that a Pap test being reviewed should be examined “through an unbiased screening review process that includes the contested case as one of a number of normal and abnormal Pap smears representing a variety of disease states.”Multiple-slide, blinded rescreening panels3,4 have emerged as unbiased objective prelitigation tests and have been used in numerous cases before assertions of a breach of the standard of practice are entertained. The guidelines in general represent a science-based approach to protect the interests of patients, laboratories, and the public alike in maintaining and protecting medical history's most effective cancer screening test.