Axillary apocrine carcinoma with Paget's disease and apocrine naevus.

Apocrine carcinoma is a rare malignant sweat-gland neoplasm with apocrine differentiation. There have been some reported cases of apocrine carcinoma with apocrine naevus. We report a case of a 78-year-old man with a painless tumour of the left axilla. Positron emission tomography (PET) showed slight fluorodeoxyglucose (FDG) uptake in both axillae. The patient underwent radical excision of the left axilla with left axillary lymph-node resection. The resected specimen showed apocrine adenocarcinoma with extramammary Paget's disease and apocrine naevus. Two years later, the patient noted enlargement of the right axilla, and PET showed increased FDG uptake. On resection of this enlarging right axilla, an apocrine naevus was found. FDG-PET is a useful method for detecting precancerous lesions, allowing monitoring of abnormal foci that are not suspicious for cancer and have no clinically apparent cause for concern.