Endocrine Mucin-Producing Sweat Gland Carcinoma

Abstract

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare low-grade sweat gland carcinoma with a strong predilection to the eyelid region. It is histologically analogous to endocrine ductal carcinoma/solid papillary carcinoma of the breast and is characterized by a multinodular solid cystic mucinous tumor with immunoreactivity to neuroendocrine markers. Only 20 cases of this unusual tumor have been reported. We present the clinical and histopathologic findings of 2 new cases of EMPSGC and review the relevant literature. The histological differential diagnosis is discussed and attention drawn to the role of immunohistochemistry in clarifying the nosological position of EMPSGC within the spectrum of cutaneous mucinous neoplasms.

Endocrine Mucin-Producing Sweat Gland Carcinoma, a Histological Challenge

“…In the breast, solid papillary carcinoma/endocrine ductal carcinoma in situ is deemed the precursor lesion to mucinous (colloid) carcinoma [3], and it is thought by many in the literature that this is also true in sweat glands. EMPSGC is believed to be the immediate precursor lesion to primary cutaneous mucinous (colloid) carcinoma [2, 3]. …”

“…Once the mass is deemed a primary skin adnexal tumor, the differential diagnosis for EMPSGC includes basal cell carcinoma (nodular subtype), nodular hidradenoma, hidradenocarcinoma, hidrocystoma, apocrine tubular adenoma, monomorphic adenoma, and dermal duct tumor [1, 2, 6, 8]. …”

“…It is therefore pertinent that a comprehensive physical exam with imaging is completed to rule out a primary breast lesion with metastases. When considering EMPSGC, the differential diagnosis also includes other skin tumors especially nodular basal cell carcinoma, nodular hidradenoma, hidradenocarcinoma, hidrocystoma, apocrine tubular adenoma, monomorphic adenoma, and dermal duct tumors [1, 2, 6, 8]. If a tumor has a lobular architecture with solid, papillary, and/or cribriform areas, evidence of neuroendocrine differentiation, and mucin production, EMPSGC should be considered.…”

Endocrine mucin-producing sweat gland carcinoma of the eyelid: A clinical and histological conundrum

“…The immunohistochemical profile of strong positivity for estrogen/progesterone receptors and cytokeratin 7 along with the histological resemblance to breast carcinoma makes it crucial to rule out the possibility of cutaneous metastases in all cases of EMPSGC. [ 5 ] However, our patient did not clinically show any mass lesion in the breast, retraction, discharge from the nipple or pain; all of which are the most common presenting signs in male breast cancer.…”

“…Whether EMPSGC represents an in situ or an invasive carcinoma depends on the presence or absence of a peripheral rim of myoepithelial cells. [ 5 ] The presence of the rim of myoepithelial cells around the tumor cells should be confirmed using smooth muscle actin (SMA). However, SMA reactivity should be interpreted with caution because staining of stromal myofibroblasts around tumor nodules may result in an erroneous impression of an intact layer of myoepithelial cells.…”