An ultrastructural analysis of breast carcinoma presenting as isolated axillary adenopathy.

Metastatic adenocarcinoma in the axillary lymph nodes of a female patient often originates from a primary tumor in the ipsilateral breast. Mastectomy may be recommended if adenocarcinoma is found in the axillary nodes even when the primary tumor is not clinically detectable. In these circumstances, the recommendation for mastectomy should be based on the firm histologic diagnosis of adenocarcinoma. In the present report, five female patients are discussed who presented with axillary lymphadenopathy without clinically evident breast masses or mammographic evidence of malignancy. Axillary lymph node biopsies, performed in each patient, were inconclusive after conventional light microscopic examination. Electron microscopy established the diagnosis of adenocarcinoma. These findings were complemented by sex steroid analyses of the tumors where possible. Each patient underwent ipsilateral mastectomy, and in each specimen an occult breast carcinoma was found. The necessity of making a precise tissue diagnosis in all cases of metastatic cancer from an unknown primary is stressed, and special techniques to accomplish this must be considered preoperatively. This is particularly important in the female patient with metastatic breast carcinoma in an isolated axillary lymph node, since ipsilateral mastectomy may be curative.