Poroma: a review of eccrine, apocrine, and malignant forms.

Poroma is a benign adnexal neoplasm of the terminal sweat gland duct. Although poromas have traditionally been thought to originate from the eccrine sweat gland, there have been cases of apocrine etiology as well. Eccrine and apocrine poromas typically present as erythematous or flesh-colored nodules on the palms and soles. As these features overlap with a multitude of differential diagnoses, it is imperative to have a firm understanding of the characteristics that make the diagnosis of poroma. In addition, the malignant counterpart to the poroma, the eccrine porocarcinoma, manifests in a similar nonspecific fashion. Case studies and literature reviews have contributed immensely to our present knowledge of poroma and porocarcinoma. Given the rarity of these neoplasms, however, there remains a relative paucity of information on atypical presentations and rates of malignant transformation. In this article, the epidemiology, clinical presentation, diagnosis, and management of poroma and porocarcinoma will be reviewed. This systematic approach may serve as a guide in navigating the diagnostic dilemma of these rare cutaneous lesions.