Subtyping of mucinous sweat gland carcinoma unnecessary

This retrospective study found no correlation between the morphology, immunophenotype and prognosis of mucinous sweat gland carcinomas, and argues against subtyping of mucinous sweat gland carcinoma using the current morphologic and immunohistochemical parameters.

The authors reviewed the charts of 16 patients who presented to a single center with vascularized, focally cystic, nonulcerated eyelid margin lesions.

Histopathologic evaluation showed that four lesions had a cystic, papillary, and solid component with an in-situ component, seven were pure invasive mucinous carcinomas, and five demonstrated both growth patterns. Immunohistochemical stains for synaptophysin were greater in pure papillary/cystic lesions (P = 0.036). Other immunohistochemical stains (chromogranin, CD56, and neuron-specific enolase) were equally distributed across growth patterns.

The results indicate that mucin-producing sweat gland carcinoma pathologically represents a continuum, from an in situ lesion to a classic invasive mucinous carcinoma. The authors conclude that neuroendocrine differentiation is common in mucin-producing sweat gland carcinoma of the eyelid and does not have prognostic significance.