We describe an autopsy case of a 65-year-old man with prostate cancer accompanied by multiple endocrine neoplasia 2A (MEN 2A), including malignant pheochromocytomas, thyroid medullary carcinomas and parathyroid hyperplasia. Metastatic lesions from the prostate primary were identified using immunohistochemistry for prostate specific antigen within both primary and metastatic pheochromocytomas in the liver. To investigate the affinity of prostate cancer for pheochromocytoma cells, immunohistochemistry was carried out using a number of antibodies and both tumors were positive for N-cadherin. Interestingly, pheochromocytomas, thyroid medullary carcinomas and prostate cancer were all positive for the anti-RET antibody. The immunohistochemical results suggest that the cell affinity may, in part, result from cell-cell adhesion via N-cadherin. Although prostate cancer is rarely associated with MEN, RET activation may have participated in the tumorigenesis of this case.