By Gary M. White, MD
The eccrine poroma (EP) is an uncommon benign adnexal tumor that typically occurs on the side of the foot. It is thought to originate from the acrosyringium or intraepidermal portion of the eccrine sweat duct. There is some evidence that the poroma may be of apocrine origin as well.
There are reported cases of multiple EPs in association with electron beam therapy and total body irradiation There have also been reports of EPs occurring at sites of chronic radiation dermatitis.
A slowly growing red nodule is typical. The sole or side of the foot is the most common site, but lesions have occurred on the back, neck, chest, cheek, and even the face. Most are flesh-colored to red or bluish-red papules, but they may present as plaques, nodules or cystic or even ulcerated lesions. Typically lesions are asymptomatic, but they can be painful and can present with serous or hemorrhagic discharge.
These benign lesions may be treated with shave removal, electrosurgical destruction or surgical excision. Partial removal may be followed by recurrence. In rare cases where a malignant poroma is suspected, wide excision with long-term follow up is needed.
A slightly pedunculated eccrine poroma.
A small eccrine poroma on the sole.
This nodule of 8 months on the shin of an elderly man was read out as a poroma with atypia.