Extramammary Borderline Phyllodes Tumor Presenting as an Umbilical Mass. (September 2021)

• Record Type: Journal Article
• Authors: Jackson, John; Walker, Eleanor; Bethune, Robert; Bracey, Tim; Mason, Chris; Mandalia, Trupti
• Is Part Of: International journal of surgical pathology. Volume 29:Number 6(2021)
• Page Start: 648
• Page End: 652
• Publication Date: 2021-09
• Subjects: accessory breast tissue -- phyllodes tumor -- borderline -- extramammary; Pathology, Surgical -- Periodicals; 617.07
• DOI: 10.1177/1066896920981632
• Languages: English
• ISSNs: 1066-8969

Abstract

Phyllodes tumors (PTs) represent a spectrum of rare, fibroepithelial neoplasms of the breast, which can be subcategorized as benign, borderline, or malignant based on their histological appearance. Accessory breast tissue may present anywhere along the embryological mammary ridge, and at distant locations as aberrant breast tissue. We present the case of a 56-year-old lady with an umbilical mass, thought to represent a strangulated hernia. Sections showed a fibroepithelial tumor with leaf-like ducts, conspicuous mitotic activity (up to 8 per 10 high-power fields), and focal infiltration into fat. Immunohistochemical studies showed diffuse positivity of epithelial cells for estrogen receptor, mammaglobin, GCDFP-15, and CK7. These findings were consistent with a borderline PT. This is the first case report of PT presenting as an umbilical mass, and the first extramammary borderline PT described.