Eccrine porocarcinoma is a rare carcinoma with eccrine differentiation arising from the sweat gland duct. It is characterized by the presence of intraepidermal and dermal nests and cords of malignant epithelial cells. The nests are sharply demarcated from the adjacent epidermal keratinocytes. The overlying epidermis may be acanthotic. Up to 15% of lesions show deep dermal intralymphatic invasion
Robson A, Greene J, Ansari N, Kim B, Seed PT, McKee PH, Calonje E (2001)
. The tumour may arise de novo or as a malignant transformation in a pre-existing poroma. Most commonly affected sites are legs, buttocks, and feet, followed by trunk and head. The lesion typically presents as a nodular or verrucous ulcerative plaque.
Eccrine porocarcinoma (malignant eccrine poroma): a clinicopathologic study of 69 cases.
Am J Surg Pathol 25: 710-20
Eccrine porocarcinoma affects predominantly elderly patients (average age 67 years). Approximately 20% of cases recur after excision; lymph node (20%) and distant (12%) metastases may also develop
Snow SN, Reizner GT (1992)
. Metastasis is associated with a high mortality rate
Eccrine porocarcinoma of the face.
J Am Acad Dermatol 27: 306-11
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
IARC Press: Lyon 2005