Syringomatous Adenoma of the Nipple: A Case Report

We report herein a 41-year-old woman who underwent excisional biopsy of a firm mass beneath the left nipple. Gross examination of the lesions revealed a firm irregularly-bordered cream-gray mass measuring 1.5×1.5×1cm which histologically exhibited an infiltrative tumor constituted by small cord-like and angulated tubules individually set in an abundant fibrous stroma. These tubular structures were lined by one or more layers of epithelial cells and had the teardrop, tadpole or comma-like shapes characteristic. On closer examination, a distinct layer of myoepithelial cells could be identified between the epithelial cells and the fibrous stroma. In most areas epithelial cells exhibited squamous differentiation with occasional keratin-filled cysts formation. Multifocal neural invasion was also evident. Eventually, with respect to mentioned features the diagnosis was a very rare syringomatous adenoma, benign tumor of the nipple which only 27 cases of it have been documented in the English literature. To the best of our knowledge this may be the first reported case in Iran.