[Malignant thymoma associated with insulinoma].

A 44-year-old male died with severe hypoglycemia (26 mg/dl). Autopsy revealed invasive thymoma in the anterior mediastinum and insulinoma in the caudal part of the pancreas. A diagnosis of insulinoma was made based on light and electron microscopic findings; it was confirmed immunohistochemically using anti-insul. antibody. According to the Annuals of Pathological Autopsy Cases in Japan between 1971-1980, 40 out of a total of 429 thymoma cases (9.3%) had associated malignancies. Because malignancies associated with total malignancies, stomach cancers, and lung cancers were 5.1%, 7.2%, 4.8%, respectively, thymoma is a frequent associated malignancy (p less than 0.005). Hematopoietic malignancies were more common in cases with thymoma than in those with other malignancies (p less than 0.0003).