Adenosis tumour of anogenital mammary-like glands

Abstract

Dear Editor: Anogenital mammary-like glands, although known to exist (as ectopic breast tissue) as early as 1872, have recently been thoroughly studied. They have been suggested to be the possible origin for various neoplastic (benign and malignant) and reactive conditions that show a striking homology with lesions in the breast. The term “adenosis tumour” was coined for a clinically detectable mammary tumour in which several benign changes, often occurring as isolated lesions of the breast, are seen in combinations. We describe a lesion that occurred in the anogenital area of a woman and apparently arose in anogenital mammarylike glands. A 64-year-old woman presented with a solitary asymptomatic lesion located in the perianal area. She was uncertain about the duration of the lesion. Her past medical history was unremarkable. Clinical examination revealed a 1.7-cm oval nodule. Rectoscopy revealed an internal haemorrhoid. The lesion was surgically removed. The patient showed no recurrence 7 months after the surgery. Histologic examination revealed a well-delimited but not encapsulated nodule with little surrounding connective tissue composed of fibrous stroma and glands and ducts, many cystic or with cellular proliferation, reminiscent of mammary glands; papillary areas and apocrine metaplasia could also be seen. An immunohistochemical study was performed, showing a myoepithelial (actin-positive) and a cytokeratin 7+/20− epithelial component with marked EMA expression but not of CEA. Approximately 15% of cells expressed oestrogen and/or progesterone receptor. Anogenital “sweat glands”, recently termed as anogenital mammary-like glands, are a newly recognised variant of cutaneous adnexal glands and may play an important role in a group of neoplastic disorders of the anogenital region in both women and men. These glands appear to be eccrine glands that transform fully or partially into apocrine glands with the capacity to form breast lobules and histologic, biochemical and ultrastructural features that fall somewhere in between conventional sweat glands and breast tissue. The secretory epithelium of mammary-like glands is characteristically tall columnar with snouts, can express both oestrogen and progesterone receptors and shows drastic periodic alterations. It is important for everybody to be familiar with mammarylike glands because they can give rise not only to tumour adenosis, but also to hidradenoma papilliferum, extramammary Paget’s disease, fibroadenoma, phyllodes tumour, anogenital mammary type sclerosing adenosis, lactating adenoma, adenocarcinomas, stromal hyperplasia and lobular hyperplasia. Adenosis originating from mammary-like anogenital glands is rare; to date, only eight cases have been documented in the literature, including the case described herein. Adenosis tumour is defined as clinically recognisable lesions that histologically primarily consist of adenosis, but also exhibits various combinations of diverse epithelial changes seen in other benign breast diseases. Int J Colorectal Dis (2008) 32:223–224 DOI 10.1007/s00384-007-0323-x