Eccrine Poroma of the Postauricular Area

Eccrine poroma is a common benign cutaneous tumor that originates in an intraepidermal eccrine duct. This tumor exhibits acral distribution (sole, palm), and is rarely encountered in the head and neck area. In fact eccrine poroma in the postauricular area has only been rarely reported. A 55-year-old female visited our hospital with a main complaint of a mass that first developed in the left postauricular area about a year previously. The mass was painless, soft, protruding, domed, and dark red in color, and had slowly enlarged (at presentation it measured $1\times1cm$). Excisional biopsy was performed. Histological examination showed distinct features, and eccrine poroma was diagnosed. Follow-up at 6 months postoperatively showed no recurrence. The frequency of eccrine poroma is dependent on eccrine sweat glands density, and thus, usually occurs on the palms or soles. For eccrine poroma in the head and neck region, the differential diagnosis must rule out other masses, such as nevus, skin tag, pyogenic granuloma, cyst, basal cell carcinoma, and seborrheic keratosis. Importantly, 18% of poromas show malignant transformation, and can develop into porocarcinoma. For these reasons, an eccrine poroma in the facial area requires histological examination, complete excision, and follow-up.