Adenocarcinoma from an unknown primary presenting in women with an axillary mass.

Adenocarcinoma from an unknown primary is generally associated with a poor prognosis. This is not the case with women who present with disease confined to one axilla, when the primary, despite negative investigations, is often found to lie in the ipsilateral breast. Twenty such patients presented to our department between 1977 and 1989 and were generally treated by radical radiotherapy to the breast and peripheral lymphatics. Local control was achieved in the axilla in 17 of the 20 patients (85%). No primary has appeared in the breast, although one patient has died of a carcinoma of the colon. The 5-year actuarial survival of the group is 66%, similar to stage II breast carcinoma patients. The value of radiological and histopathological investigations is discussed. The cosmetic results are good and in view of the excellent local control achieved by irradiation we feel mastectomy is unnecessary in this rare presentation of breast cancer.