NEUROENDOCRINE CARCINOMA IN THREE AIDS PATIENTS

Abstract

Background: Poorly-differentiated neuroendocrine carcinoma (or small-cell undifferentiated carcinoma) is a rare malignancy when it occurs in an extra-pulmonary site or in the young, and has not been reported as an AIDS-related malignancy. BK virus is prevalent in many immunodeficiency disorders and has been associated with neuroendocrine tumors in an animal model as well as with several rare human malignancies. Methods: Clinical histories and pathology material were reviewed on three cases of neuroendocrine carcinoma in individuals with AIDS. H&E slides, special stains, immunohistochemistry and electron micrographs were studied to confirm neuroendocrine differentiation of each tumor. Results: All patients were males with symptomatic AIDS. Case 1 (1982) represented invasive neuroendocrine carcinoma of the rectum with metastases to the liver in a 26 year old. Case 2 (1985) was a pancreatic primary, metastatic to regional lymph nodes, and occurring in a 27 year old. Case 3 (1996) consisted of an invasive tumor localized to the tracheobronchial tree in a 13 year old. H&E stained sections show infiltrating tumor cells arranged in sheets and nests. All of the tumors had a small-cell morphology with little cytoplasm and round to oval nuclei with a "salt-and-pepper" chromatin pattern. All three cases were confirmed to have neuroendocrine differentiation by special stains, immuno-histochemistry or electron microscopy. Conclusions: Poorly differentiated neuroendocrine carcinomas are rare, especially in young patients. Therefore, in the setting of young AIDS patients, these tumors may represent a heretofore unrecognized AIDS-related malignancy. The possible relationship between BK virus and the neuroendocrine carcinomas found in these patients will be investigated further.