Apocrine adenoma of the breast: report of a case with investigation of lectin binding patterns in apocrine breast lesions.

A 19-year-old female presented with a left breast mass clinically felt to be a fibroadenoma. Pathologically, it was found to be a pure apocrine adenoma of the breast. This is an extremely rate entity, with this case being only the third to be reported. Criteria for diagnosis include: (a) qualification as adenoma; (b) establishment of apocrine differentiation; and (c) distinction from the relatively more frequent malignant counterpart, apocrine carcinoma.