Histological examination has a major impact on macroscopic necropsy diagnoses

Background: Necropsy is the gold standard for clinicopathological discrepancy studies and epidemiological surveys. Inadequate sampling or lack of tissue may hamper the final interpretation and quality of the necropsy. Aim: To compare the histological and gross necropsy diagnoses of different organs. Methods: A retrospective comparison of the provisional reports (gross findings only) and the final reports (after histological examination) of the necropsies performed at the department of pathology of the Hospital das Clinicas, Sao Paulo University, Brazil, a large tertiary care complex, in 2001. The total number of diagnoses listed for the lungs, heart, liver, pancreas, kidneys, and spleen were calculated. Findings were categorised into concordant/refined diagnosis, discordant/additional diagnosis, histology needed, and inconclusive. Results: Three hundred and seventy one postmortem reports were analysed. There were 214 men and 157 women, with a mean age of 50.3 years, ranging from 1 to 92. The lung received the highest number (954) and the pancreas the lowest number (390) of diagnoses. The highest frequencies of discrepancies between the gross and microscopic findings were found in the lung and the liver: 38.7% and 35.1%, respectively. The brain had the lowest frequency of discrepancies. In a small number of cases, the final diagnosis could only be achieved through microscopic analysis, with the highest frequency being found in the kidneys (8.5%). Conclusions: Histological analysis has a major impact on previously performed gross diagnosis at necropsy, especially in the lungs, liver, and kidneys. Adequate sampling and histological analysis are important for necropsy quality.