Eccrine Carcinoma

Excerpt

Eccrine carcinoma (EC) is a rare carcinoma that originates from the eccrine sweat glands of the skin and accounts for less than 0.01% of diagnosed cutaneous malignancies. Sweat gland tumors have traditionally subdivided into four broad groups: eccrine, apocrine, mixed origin (eccrine and apocrine), and other unclassifiable sweat gland tumors. Eccrine tumors further divide into benign and malignant. Benign entities include poroma, hidradenoma, spiradenoma, cylindroma, syringometaplasia, syringoma, syringofibroadenoma, and chondroid syringoma. Malignant eccrine carcinoma entities include porocarcinoma, hidradenocarcinoma, malignant spiradenoma carcinoma, malignant cylindroma, syringoid eccrine carcinoma, microcystic adnexal carcinoma, mucinous carcinoma, adenoid cystic carcinoma, and ductal papillary adenocarcinoma. Other un-classifiable sweat gland tumors include eccrine ductal carcinoma, basaloid eccrine carcinoma, clear cell eccrine carcinoma, and non-specified sweat gland carcinomas.

Malignant sweat gland tumors are heterogeneous neoplasms of different biological behavior. The principal characteristic of these tumors is that they are locally aggressive and show a high rate of recurrence. Separation of eccrine carcinoma has traditionally been according to their behavior into low grade and high grade malignant. Proper identification of eccrine carcinoma is sometimes challenging due to the morphological similarity to other common tumors and the lack of consistent immunohistochemical markers.