Clinicopathological concordance in the diagnosis of skin diseases: a retrospective analysis of 5000 histopathology reports

BACKGROUND: The accuracy of clinical diagnoses of skin diseases has not been researched in Saudi Arabia. OBJECTIVES: Assess concordance between the histopathological and clinical diagnosis in skin diseases. DESIGN: Retrospective. SETTING: Academic tertiary care center. METHODS: Demographic, clinical and pathological data were collected from the medical record for the period 1997-2013. MAIN OUTCOME MEASURES: Concordance between the pathological and clinical diagnosis. SAMPLE SIZE: 4268 cases. RESULTS: Of 4268 biopsies, 2440 (58.1%) were females. The mean age (SD) of patients was 36.9 (17.8) years. The three most common locations from which skin biopsies were retrieved in descending order were the lower extremity (1123; 29.1%), head, neck, scalp and hair (1033; 26.7%) and trunk (853; 22.1%). Overall concordance was 75.9% (partial concordance 47.6%, full concordance 28.3%). Biopsies from the oral mucosa and lips had the lowest concordance (overall 58.5%, full 26.4%) at P=.004. Overall concordance was highest for the following three diagnoses: malignant neoplasms, 88%; vesiculobullous diseases 87%; urticarias, erythemas, and purpuras 87%. CONCLUSION: There is considerable variability in concordance among different histopathological diagnoses. The full concordance between the clinical diagnosis and the pathological diagnosis is low. This is a reflection of the fact that the biopsies were obtained only in cases where the clinical diagnosis was a dilemma. LIMITATIONS: Single center, retrospective, incomplete medical records, low percentage of biopsies were assessed by dermatopathologists. CONFLICT OF INTEREST: None.