Endocrine mucin‐producing sweat gland carcinoma and associated primary cutaneous mucinous carcinoma: Review of the literature

Abstract

Background Endocrine mucin‐producing sweat gland carcinoma (EMPSGC) is a rare, low‐grade, cutaneous adnexal carcinoma with neuroendocrine differentiation. It is considered to be a precursor of invasive neuroendocrine type primary cutaneous mucinous carcinoma (PCMC). Objective To review clinicopathological literature summary of EMPSGC and associated neuroendocrine PCMC from all reported cases and compare its behavior vs non‐neuroendocrine PCMC data reported in the literature. Methods A review of English literature of all EMPSGC cases with and without associated PCMC was carried out. Results EMPSGC was associated with invasive neuroendocrine type PCMC in 35.7% of cases. We found the recurrence rate of PCMC associated with EMPSGC of about 12.3%, which is much less than the 30% recurrence rate reported for the non‐neuroendocrine subtype of PCMC. The non‐neuroendocrine subtype of PCMC shows a 4% and 11% rate of distant and lymph node metastasis, respectively, vs EMPSGC‐associated neuroendocrine type of PCMC, which is very indolent and only one recent case of locoregional metastasis out of 190 EMPSGC cases has been reported so far. Limitation Limitation of our study includes data derivation from case reports and case series in the literature. Conclusion The prognostic benefits for this cohort of patients may be considered in their overall management.

Recurrent Neuroendocrine Primary Cutaneous Mucinous Carcinoma of the Scalp After Complete Excision

“…In contrast, the group of PCMCs that showed positivity (variable distribution and intensity) for neuroendocrine markers-called "neuroendocrine PCMCs" and often associated with an EMPSGCfeatured focal, smaller pools of extracellular mucin, were cytologically bland, and showed a more "classic" neuroendocrine histologic appearance with stippled nuclear chromatin. 4,5 This case did not readily reveal its neuroendocrine component on first-glance, routine H&E histology. Morphologically, it falls more in line with the criteria delineating a nonneuroendocrine subtype; yet, upon IHC staining, it showed expression for neuroendocrine markers, thus underscoring the importance of obtaining IHC to elucidate subtle neuroendocrine features.…”

Dome-Shaped Periorbital Papule

“…Nests of uniform tumor cells are composed of small-to medium-sized epithelial cells with monomorphic nuclei showing fine to stippled chromatin. 2 Histologically, EMPSGC resembles a solid papillary carcinoma of the breast, which is attributed to their common embryologic origin. 3 Intracytoplasmic and extracellular mucin often are seen on hematoxylin and eosin staining.…”

“…3 Intracytoplasmic and extracellular mucin often are seen on hematoxylin and eosin staining. 2 Variable immunohistochemical stain expression has been reported, including positive staining with synaptophysin and chromogranin. Other markers include cytokeratin CAM 5.2, epithelial membrane antigen, estrogen or progesterone receptors, and cytokeratin 7.…”

“…Histologically, primary cutaneous mucinous carcinoma that has transformed from EMPSGC would show an infiltration of tumor nests with desmoplastic stroma or mucin pools with clusters of tumor cells. 2 Primary cutaneous adenoid cystic carcinoma is a rare malignant tumor that often presents on the head and neck. It usually appears as a single, slowly growing subcutaneous nodule or multinodular plaque.…”

“…8 The characteristic features of basal cell carcinomas, such as nests of basaloid cells with peripheral palisading cells, retraction of adjacent stroma, increased apoptosis and mitotic figures, and connection to the epidermis, can be helpful to distinguish basal cell carcinoma histologically from EMPSGC. 2 Apocrine hidrocystomas clinically present as round, flesh-colored, shiny or translucent, dome-shaped papules or nodules near the eyelid margin or lateral canthus. 9 Histologically, they are composed of proliferating apocrine secretory coils with an epithelial side of cuboidal or columnar cells and a luminal side exhibiting decapitation secretion (Figure 3).…”