Occult breast carcinoma presenting as axillary metastases

Breast carcinoma presenting with axillary lymphadenopathy and no clinical or radiological evidence of a primary tumor is a rare presentation. We aimed to examine the management of the breast by observation, radiation therapy, or mastectomy.

Departmental records from 1979 to 1996 of unknown primary presentations and cases of T0N1-2M0 breast carcinoma were reviewed to find cases of occult breast carcinoma presenting as axillary lymphadenopathy with no clinical or imaging evidence of a primary tumor.

There were 6047 presentations of breast carcinoma with 20 cases of occult breast carcinoma meeting the criteria. The breast was treated by observation in 6 cases, mastectomy in 2 cases, and radiotherapy to the intact breast in 12 cases. Eighty-three percent of patients (5 of 6 patients) who had observation of the breast had a local recurrence, compared to 25% who had radiotherapy to the intact breast (3 of 12 patients) and 0% who had a mastectomy (0 of 2 patients). The median recurrence-free survival was 7 months in patients who had observation of the breast, compared to 182 months in patients who had local treatment. Three of the 6 patients who underwent breast observation have died whereas 1 of the 14 who had local treatment have died, with a mean follow-up of 73 months. It was found that patients having observation of the breast had a poorer recurrence-free survival (p = 0.003) and overall survival (p = 0.05) compared to those having local treatment of the breast.

Patients with such a presentation should have a complete physical examination, mammography, ultrasound, and MRI of the breasts. If there remains no evidence of a primary tumor, an axillary dissection should be carried out and the breast treated by radiotherapy or mastectomy. Observation of the breast is not a recommended option.