Axillary masses are uncommon alterations when detected as an isolated finding. We evaluated 31 patients with isolated axillary masses. Patients with alterations of the breasts or the upper limbs or with Ipsilateral chest lesions were excluded from the study. Nine patients had occult breast cancer, 5 of them in the contralateral breast. Seven had metastatic lymph nodes of non-ductal origin, and 1 had carcinoma of apocrine cells with metastasis to the axilla. Four patients had benign lymphadenopathy which disappeared spontaneously, and 4 others had ruptured infundibular follicular cyst, nodular fibromatosis, inflammatory tuberculous and inflammatory rheumatoid lymphadenitis. Five had an ectopic breast (2 with a fibroadenoma and 3 with fibrocystic changes). One patient had an axillary lipoma. The mean age of patients with malignant pathology was 55.1 +/- 10.9 years, and the mean age of patients with a benign pathology was 43.1 +/- 14.7 (P < 0.01). Chest X-ray and bilateral mammography are useful when the cause of the mass cannot be determined by taking a detailed history of neoplastic or infectious antecedents, by careful physical examination of the skin of the arms, trunk and neck, or by palpation of the breasts and thyroid. Fine needle aspiration biopsy distinguishes between benign and malignant pathologies. In cases of indeterminate neoplasia, complete axillary dissection for diagnosis is indicated.