Discrepancies in dermatopathology diagnoses: the role of second review policies and dermatopathology fellowship training

Background: Expert consultation and institutional policies mandating second review of pathologic diagnoses in the course of referral have been advocated to optimize patient care.

Objective: We sought to investigate the rate of diagnostic discrepancies between pathologists with and without dermatopathology fellowship training.

Methods: All available outside pathology reports were reviewed for material sent to the University of Pittsburgh Medical Center Dermatopathology Unit during 1 year. The outside diagnosis was compared with the diagnosis rendered by the referral dermatopathology service. Cases were assigned into 1 of 4 categories: melanocytic neoplasm, nonmelanocytic neoplasm, inflammatory, and other. For each case, the outside pathologist's level of dermatopathology training was noted. Any change in diagnosis resulting in significant alteration in therapy or prognosis, as dictated by the accepted standard of care, was considered a major discrepancy.

Results: A total of 405 cases were reviewed. In 51 cases (13%), no preliminary diagnosis was rendered at the outside facility. The referral diagnosis differed from the outside diagnosis in 226 cases (56%), and major discrepancies were identified in 91 cases (22%). Of these 91 cases, 84 were received from outside pathologists who were not dermatopathology trained and 7 were received from pathologists with dermatopathology training. The 91 cases with major discrepancies were categorized as: 36 nonmelanocytic neoplasms (40%), 30 inflammatory (33%), 23 melanocytic neoplasms (25%), and 2 other (2%).

Limitations: This was a retrospective study limited to 2 consultant dermatopathologists at an academic referral center, which typically receives and reviews select cases.

Conclusion: Dermatopathology fellowship training is associated with a substantial decrease in major diagnostic discrepancies. Pathologists without dermatopathology fellowship training tend to successfully identify those cases for which expert consultation is most useful.