Multiple intracerebral metastases from an islet cell carcinoma of the pancreas: case report.

Computed tomography and magnetic resonance imaging of an 85-year-old woman with bitemporal headaches revealed cystic lesions in the basal ganglia and cerebellum. The patient remained neurologically asymptomatic until just before her death at age 89. Autopsy revealed tumors of the brain, lungs, liver, periaortic lymph nodes, adrenal gland, and the pancreas. Light microscopy demonstrated a malignant small cell tumor with scant cytoplasm. Electron microscopy revealed intracytoplasmic dense core vesicles, characteristic of neuroendocrine tumors, which prompted the diagnosis of islet cell carcinoma. All lesions were found to be microscopically similar. Previous reports of islet cell carcinoma metastatic to the brain could not be found. This case emphasizes the importance of electron microscopy in cases of small cell neoplasms in the brain.