How accurate are the suggested diagnoses on biopsy requisitions for inflammatory skin disease? A retrospective study of 348 cases.

Clinical information is often critical to the histopathologic interpretation of cutaneous biopsies for inflammatory skin diseases. This information is often conveyed to the dermatopathologist as list of possible diagnoses. We reviewed 348 cases of biopsied inflammatory skin disease and measured the correlation between the original clinical differential diagnoses on the pathology requisition and the patient's final diagnosis. The final diagnosis was included among the suggested diagnoses in 270 of 348 (78%) cases reviewed. In 191 of 270 (71%) correctly diagnosed cases, the final diagnosis was listed first among those included in the differential diagnoses. The total number of suggested diagnoses did not correlate with overall diagnostic accuracy. The most commonly neglected diagnoses were eczematous dermatitis, psoriasis, lichen planus, and granuloma annulare. We conclude that the differential diagnosis submitted with pathology specimens for inflammatory skin disease includes the final diagnosis in a majority of cases. The first listed diagnosis has the highest positive predictive value. Submitting longer differential diagnosis lists did not improve diagnostic accuracy.