Ductal carcinoma in-situ arising in mammary-like glands of the vulva

Recently a variant of cutaneous glands has been recognized in the anogenital region that combines the morphologic and immunohistochemical features of eccrine, apocrine, and mammary glands, so-called 'mammary-like glands of the vulva'. Carcinoma arising in mammary-like tissue of the vulva is a rare occurrence. So far, there have been 11 cases of primary, mammary-type invasive carcinoma and one case of in-situ carcinoma reported in the vulva. We describe an unusual case of ductal carcinoma in-situ without invasion arising in mammary-like glands of the vulva. A 57-year old woman presented with a 1-year history of a 1 cm nodule in the right labium majus. Excision showed ductal carcinoma in-situ with cribriform and papillary morphology in an adenosis-like lesion associated with mammary-like glands. No invasion into the stroma was identified. Immunostains were positive for gross cystic disease fluid protein 15 (GCDFP-15) and estrogen and progesterone receptors. An extensive survey including bilateral mammograms was negative. One year postoperatively, the patient shows no evidence of disease. To our knowledge, this represents the second case of DCIS associated with mammary-like glands of the vulva reported in the English literature.