We report the third case of eccrine syringofibroadenoma (ESFA) arising in peristomal skin. A 55-year-old man presented with a 15- x 10-cm pale pink verrucous, exophytic, intermittently tender plaque involving his ileostomy site. He had undergone proctocolectomy with ileostomy creation 33 years prior for ulcerative colitis. The clinical differential diagnosis included granulomatous dermatitis, infection (fungus or atypical mycobacterium), or neoplasm. A punch biopsy specimen was performed and showed ESFA. Although ESFA is considered to be benign, recent reports have demonstrated an association of ESFA with malignancy or malignant transformation of ESFA. Furthermore, ESFA and reported cases of ileostomy carcinoma share similar clinical symptoms at presentation including pain, irritation, ulceration, bleeding, and the presence of a fungating mass. The lesion was, therefore, excised in toto and the excisional specimen showed no evidence of malignancy. We speculate that ESFA is a reaction to chronic irritation and, analogous to other long-standing reactive processes such as lichen sclerosis or burn scar ulcers, may be associated with malignant transformation. Because of this possibility and the clinical overlap with ileostomy carcinoma, peristomal ESFA should be treated with complete excision. If it is not amenable to complete excision because of lesion size or anatomic complexity, generous sampling and close clinical follow-up are recommended.

Eccrine syringofibroadenoma with co-existent squamous cell carcinoma. J Cutan Pathol. 2007 Dec;34 Suppl 1:71-4.

Eccrine syringofibroadenoma (ESFA) is a rare, benign adnexal tumor arising most often on the extremities of elderly individuals. It is typically a slow-growing, flesh- to reddish-colored nodule or plaque. Histologically, the tumor consists of anastomosing cords of cuboidal epithelial cells surrounded by a fibrovascular stroma containing plasma cells. The cords contain scattered ductal structures lined with cuboidal cells resembling eccrine ducts. The co-existence of ESFA with squamous cell carcinoma has been described, eliciting the term eccrine syringofibroadenoma. The differential diagnosis includes poroma, porocarcinoma, fibroepithelioma of Pinkus and clear cell acanthoma. ESFA stain positively with epithelial membrane antigen and carcinoembryonic antigen. Cytokeratin studies have been inconsistent.