Occult breast cancer and axillary mass.

Occult breast cancer presenting with axillary metastases is an unusual presentation and can be a diagnostic and therapeutic challenge. A comprehensive work-up, including mammogram, sonogram, magnetic resonance imaging, and even pathologic examination of the mastectomy specimen may not disclose the primary tumor in up to one third of patients. Traditionally, occult breast cancer is treated with total mastectomy and axillary dissection, but accumulating data suggest that primary breast irradiation following axillary dissection may provide an equivalent survival with the advantage of breast conservation. Occult breast cancer patients are eligible for adjuvant chemotherapy and radiation as stage II/ III node-positive patients would be treated. Overall, the prognosis for occult breast cancer is equivalent to or slightly better than staged counterparts with detectable primary breast tumors.