Microcystic Adnexal Carcinoma: An Uncommon Tumor with Debatable Origin

Abstract

We report two cases of this unusual tumor illustrating some of its characteristics. Our review emphasizes the divergent opinions concerning its differentiation profile and its origin. An organoid nevus as the origin of microcystic adnexal carcinoma in one of our patients is discussed in this context.

Microcystic adnexal carcinoma: Treatment with Mohs micrographic surgery

“…11 Although patients usually present with this tumor in the fourth to sixth decade of life, the age range may be much wider, and there are several reports of tumors occurring in children in their second decade of life. 10,11,12,15 There appears to be an equal distribution of MAC between the sexes, 11,16 but in a few series there seems to be a possible female predominance. 8,12 In our study, there were approximately equal numbers of males and females (21 and 23, respectively) and the mean age was similar to previous reports (54 6 19 years).…”

“…The histologic differential diagnosis include trichoadenoma, syringoma, desmoplastic trichoepithelioma, morpheaform BCC, SCC, and metastatic breast carcinoma. 8,11,16 The use of histochemical stains for carcino-embryonic antigen (CEA), epithelial membrane antigen, and cytokeratin, which are expressed by MAC, may help in making the final diagnosis. 17 These difficulties in the clinical and histopathological diagnosis, result in a many cases of misdiagnosis, especially if only a superficial biopsy is obtained.…”

Microcystic adnexal carcinoma: A focused review and updates

“…These ductal structures are surrounded by a deep pink sclerotic stroma that is often fibrotic and commonly shows perineural and intramuscular invasion (Friedman et al, 1999;Wetter and Goldstein, 2008). This suggests that MACs likely originate from a pluripotent keratinocyte that differentiates along both eccrine and folliculosebaceousapocrine pathways and this accounts for the biphasic histological appearance (Goldstein and Barr, 1982;Ongenae et al, 2001;Lober and Larbig, 1994;Aasi, 2013). The tumor cells often appear benign with lack of cytologic atypia, and few if any mitosis (Goldstein and Barr, 1982).…”

Microcystic Adnexal Carcinoma

“…The differential diagnosis includes syringoma and desmoplastic trichoepithelioma, though these do not extend deeply into the dermis or subcutis and do not show perineural invasion [ 1,3,38 ] .…”