Twitter177 year old woman with left upper lid lesion noted for 4 months with no pain or enlargement. Clinical impression: benign cyst.

 What is the most likely diagnosis?

A. Endocrine mucin producing sweat gland carcinoma.
B. Nodular hidradenoma/hidradenocarcinoma.
C. Nodular basal cell carcinoma.
D. Adenoid cystic carcinoma.




The answer is A.

p40 01
Clinical: Endocrine mucin-producing sweat gland carcinoma is a rare adnexal tumor of the skin with a predilection for the skin of the eyelid, presenting as a slow growing, solitary papule/cyst. The tumor is most frequent in elderly women. Primary breast cancer should be clinically ruled out.

Histologic features: Well circumscribed, dermal based tumor composed of epithelial nests/cords with solid, papillary, or cribriform patterns floating in pools of mucin. Within the nests are ductal/tubular spaces with mucin. The cells are medium sized, monomorphic, and have round to oval nuclei with rare mitotic activity. It is histologically and immunohistochemically analogous to solid papillary carcinoma of the breast.
Focal CK5/6 and p63 staining favor cutaneous primary.
Positive: CK7, ER, PR, GCDFP-15, neuroendocrine markers (synaptophysin, chromogranin)
Negative: CK20

The differential diagnosis also includes metastatic mucinous carcinoma (breast, colon) and other skin tumors such as nodular basal cell carcinoma, nodular hidradenoma, hidradenocarcinoma, hidrocystoma, apocrine tubular adenoma, monomorphic adenoma, dermal duct tumors, and adenoid cystic carcinoma.

 Contributed by Ian Martin, M.D.