Dermoscopy of a Non-Pigmented Eccrine Poroma

Eccrine poroma, first described by Goldman and Pinkus in 1956, is a rare benign tumor of the intraepidermal portion of the eccrine sweat duct. It represents 10% of all sweat gland tumors, and only 0.0058% of epithelial skin tumors. However, it can progress to its malignant counterpart, the porocarcinoma. It commonly occurs on soles and palms, but can also be found on other anatomic sites. As a result of its morphologic variability, it is usually difficult to recognize clinically. Hence the utility of using dermoscopy to guide the diagnosis and eliminate other differential diagnosis. We present a case report of a 54 year old male patient presenting a non-pigmented eccrine poroma of the heel, which we noticed while he was hospitalized for a management of rheumatoid purpura. Through our case, we present a detailed review of clinical and dermoscopical features of this rare tumor along with its histopathological caracteristics, with special interest to dermoscopy.