Visceral cancer metastasis to pituitary adenoma: Report of two cases

BACKGROUND We report two cases of metastases from visceral cancers to pitui tary adenomas, and review the literature. CASE DESCRIPTION Two female patients, aged 75 and 87 years, underwent trans esophageal surgery for presumably benign pituitary adenomas. Using extensiv e immunostaining studies, histopathological examination showed that the sur gical specimens from both patients were composed of metastatic deposits wit hin gonadotropin adenomas. Fourteen cases of metastases to pituitary adenomas have been mentioned in 1 1 reports in the literature. In all cases, the correct diagnosis was made a fter autopsy or histopathological studies, even in patients known to suffer from visceral malignancies. In our cases, immunohistochemical studies were conclusive in characterizing the two distinct tumor components. The pathog enetic mechanisms favoring the development of metastases in pituitary adeno mas are discussed, especially those altering the normal hypophyseal circula tion. CONCLUSION Neurosurgeons performing pituitary surgery should be aware of th e possibility of metastases in pituitary adenomas. (C) 2001 by Elsevier Sci ence Inc.