Eccrine poroma on the face: An atypical presentation

Abstract

An eccrine poroma is a solitary tumor arising from the eccrine duct epithelium in the epidermis. The lesions commonly occur on the sole of the foot, the hands, and occasionally on the nose, eyelids, neck, and chest. We report a patient who presented with a slow-growing nodular lesion over her left cheek, prompting a diagnosis of basal cell carcinoma or keratoacanthoma. Biopsy from the nodule revealed a well-defined epidermal tumor with uniform small cuboidal cells with rounded deeply basophilic nuclei, few narrow ductal lumina, and occasional cystic spaces confirming the diagnosis of an eccrine poroma.

Dermoscopy of a Non-Pigmented Eccrine Poroma

“…This rare tumor may exhibit polymorphic features that can make the diagnosis difficult [8]. Differential diagnosis described in previous case reports includes a wide range of benign and malignant lesions, such as pyogenic granuloma, hemangioma, seborrheic keratosis, wart, melanocytic nevus, Kaposi sarcoma, cysts, and basal and squamous cell carcinoma [3,5,8]. Moreover, it can mimic malignant tumors, including amelanotic melanoma, which emphasizes the importance of characterizing the dermoscopic patterns of non-melanocytic lesions [6].…”

“…The tumor is composed of cuticular and poroid cells with a sharp line of demarcation between tumor cells and normal epidermis [5]. These tumor cells are uniformly cuboidal with a round basophilic nucleus, and are connected by intercellular bridges [8]. They have abundant glycogen that gives the cytoplasm a pale appearance [5].…”

“…In addition, enzyme histochemical staining shows prevalence of eccrine enzymes such as phosphorylase and succinate dehydrogenase [8]. By contrast, poromas are Ber-Ep4 negative helping to exclude basal cell carcinoma [3].…”

Benign eccrine poroma of neck: an unusual presentation

“…[3][4][5] Clinically, benign poromas usually present as solitary, plaques, papules or nodules and can mimic benign and malignant melanocytic and non-melanocytic lesions. 6 The surface can be smooth or verrucous and color can be pink, red or normal skin type. On the other hand, eccrine porocarcinoma may appear exophytic and ulcerative.…”

“…[3][4][5] Clinically, poromas usually present as solitary, plaques, papules or nodules and they can mimic benign and malignant melanocytic and non-melanocytic lesions. 6 Being a benign adnexal lesion, treatment is curative. Superficial lesions are treated with simple excision or electrosurgical destruction.…”