8409/0 Eccrine poroma


ICD-O-3 topography code: C44

Poromas are benign, well circumscribed sweat gland neoplasms with eccrine or apocrine differentiation. They may arise in any cutaneous location, but are typically found on acral sites. The tumour usually presents as a small (generally <1cm), solitary, dome-shaped papule, nodule, or plaque. It is histologically characterized by of a proliferation of uniform basaloid cells, focal ducts lined by cuticles, and cystic structures. Broad columns of epithelial cells extend from the lower epidermis into the dermis. The epithelium is sharply demarcated from neighbouring keratinocytes. The stroma surrounding the lesion is often highly vascular. Mitoses and small areas of necrosis may be observed, but are of no prognostic significance.
Poromas typically arise in middle-aged adults. The tumours are benign, complete excision is curative1
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
3rd Edition
IARC Press: Lyon 2005