Positron emission tomography in diagnosis of occult adenocarcinoma of the breast.

Occult adenocarcinoma with clinically apparent axillary lymphadenopathy represents a challenging surgical problem. Mammography is frequently unable to identify a primary breast carcinoma, and extramammary sources are common and equally difficult to identify. This may leave the clinician and patient with a conundrum of whether to proceed with "blind" mastectomy. A 35-year-old white female presented with axillary adenopathy and a normal breast physical exam. Mammography was unable to demonstrate a specific tumor. Excisional biopsy of the axillary lymph node demonstrated metastatic adenocarcinoma. Positron emission tomography showed increased uptake in the breast and the axilla, consistent with breast carcinoma and axillary metastases. The patient underwent modified radical mastectomy and pathologic review of the specimen proved infiltrating ductal carcinoma in the breast with metastatic nodes. Positron emission tomography may be helpful in localizing occult carcinoma of the breast that presents with metastatic lymph nodes and in excluding other potential primaries.