Syringocystadenocarcinoma Papilliferum: A Rare Malignant Sweat Gland Tumor.

A 73-year-old Hispanic woman presented to the clinic with an erythematous, friable 3.0 cm × 2.7 cm × 0.7 cm mass located on the posterior vertex of the scalp (Figure 1). The lesion had been present since birth but had recently begun to bleed intermittently, prompting evaluation. A biopsy was obtained, revealing a tumor with irregular, complex papillomatous invaginations lined by a two-layered epithelium. Atypical and crowded columnar cells lined the luminal aspect, while cuboidal cells lined the epithelium adjacent to the stroma (Figure 2). Decapitation secretion was noted in several areas on the luminal surface.