ABERRANT DIAGNOSES BY INDIVIDUAL SURGICAL PATHOLOGISTS

Methods of auditing the performance of histopathologists, such as exte rnal and internal quality assurance, clinicopathological conferences, and ''double-reporting'' of microscopic slides, show significant diagn ostic errors in at least 1.2% of reports. Although some of these are i n well-recognized areas of difficulty, such as melanoma or lymphoma, m ost errors are in common biopsy specimens. We have developed a method that compares diagnostic patterns of individual histopathologists. Thi s aims to identify specific diagnoses that a pathologist makes more or less frequently than other colleagues and enables the individual to r eflect on his or her own histologic expertise in reporting on specific biopsy results. The bottom line diagnoses of transurethral resection of prostate specimens; rectal, gastric, and bladder biopsy samples; an d endometrial curettages were analyzed retrospectively. Analyses were performed on diagnoses made by at least 15 pathologists on each specim en type and expressed as a standardized ratio (SR) with 95% confidence intervals (CI). An SR of 1.0 indicated a pattern of diagnosis matchin g the combined pattern of other colleagues. An SR <1.0 indicated relat ive ''underdiagnosis'' and an SR >1.0 indicated relative ''overdiagnos is.'' Diagnostic rates of individual pathologists whose CIs did not st raddle the value of 1.0 were considered aberrant, although not necessa rily incorrect. The 47 of 226 (20.8%) aberrant SRs included four patho logists' diagnoses of prostatic carcinoma, three each of endometrial, rectal, and bladder carcinoma, and one of gastric malignancy. This met hod, which could easily be automated and used regionally or nationally , should provide pathologists with a profile of their diagnostic patte rns in comparison with their peers.