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

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.

Conclusions: Limitation of our study includes data derivation from case reports and case series in the literature. Conclusions: The prognostic benefits for this cohort of patients may be considered in their overall management.