Histological assessment of chronic pancreatitis at necropsy

To evaluate the histological criteria used to diagnose chronic pancreatitis; and to assess interobserver variation among general pathologists.

Forty five cases of chronic pancreatitis diagnosed in necropsy were reviewed to determine whether the diagnosis was acceptable retrospectively. These cases were diagnosed initially as chronic pancreatitis in the final necropsy report complied by general pathologists. In reviewing these cases, special attention was paid to irregular fibrosis and destruction of the lobular architecture.

The 45 cases were re-assigned to seven different diagnostic categories: chronic pancreatitis, 21 (47%) cases; interstitial fibrosis with or without chronic inflammation, 11 (24%) cases; repair stage of acute pancreatitis, four (9%) cases; severe fatty infiltration, three (7%) cases; chronic inflammation without interstitial fibrosis, two (4%) cases; haemochromatosis, one (2%) case; and undetermined, three (7%) cases.

The histological spectrum of chronic pancreatitis was very wide and it was often misdiagnosed. Acinar atrophy, acinar dilation and intralobular fibrosis were diagnostic of chronic pancreatitis. Differential diagnoses include the repair stage of acute pancreatitis, severe fatty infiltration and haemochromatosis. Recognition of these findings may help to reduce overdiagnosis of chronic pancreatitis.