Malakoplakia of the pancreas with diffuse lymph-node involvement

We report a case of malakoplakia involving the pancreas in a 74-year-old man with associated regional lymphoadenopathy. Histological examination of both pancreas and lymph nodes revealed a diffuse histiocytic infiltrate containing numerous Michaelis-Gutmann bodies. Electron microscopy supported the diagnosis of malakoplakia and showed bacterial-like structures. Differential diagnosis includes myofibroblastic inflammatory tumor and histiocytic neoplasms. Lymph-node involvement during malakoplakia is extremely rare and it has never been documented microscopically. Lymphohematogenous spread of bacteria may be the cause of the nodal involvement, which, however, does not appear to influence the clinical course of the disease.