Neuroendocrine activity in metastatic breast carcinomas.

The expression of NSE and hormone immunoreactivity were examined in lymph node metastases from 15 primary breast carcinomas (6 NSE-positive and 9 NSE-negative). NSE immunoreactivity was expressed in metastases in 7 cases. Both the primary tumour and lymph node metastasis(es) were NSE-positive in 3 cases. In 4 cases NSE-negative primary tumours were associated with NSE-positive lymph node metastases. In 2 of the 7 cases with NSE-positive metastases, the metastatic lesions did not express uniform NSE immunoreactivity. Immunoreactivity for hormones (gastrin (1 case), prealbumin (2 cases), ACTH and beta-endorphin (1 case) and somatostatin (1 case] was present in 5 of the 7 NSE-positive lymph node metastatic lesions. In one case only the same hormone (gastrin) was expressed in both the primary tumour and its lymph node metastasis. The present study shows that no relationship exists between primary tumours and the corresponding lymph node metastases with regard to NSE and hormone immunoreactivity.