Mucin-producing sweat gland carcinoma of the eyelid: diagnostic and prognostic considerations.

Abstract

To describe the clinical and pathologic characteristics of mucin-producing sweat gland carcinoma of the eyelid and to determine whether neuroendocrine differentiation is of prognostic significance. Retrospective interventional case series. Search of the New York Eye and Ear Infirmary pathology database between 1990 and 2011 identified 16 patients with mucin-producing sweat gland carcinoma. Clinical, histopathologic, and immunohistochemical analyses were performed on all identified cases. The patients presented with vascularized, focally cystic, nonulcerated eyelid margin lesions. Histopathologic evaluation showed that 4 lesions (25%) had a cystic, papillary, and solid growth pattern with an in situ component, 7 (44%) were pure invasive mucinous carcinomas, and 5 (31%) demonstrated both growth patterns. Immunohistochemical analysis of 15 tumors showed that pure cystic/papillary lesions had a significantly greater percentage of synaptophysin-immunoreactive cells (P = .036). There was no significant difference in the number of neuroendocrine markers expressed or in the intensity of immunostaining among the 3 different growth patterns. Re-excision for margin clearance was performed in 8 of 13 cases (61.5%). Two of 13 lesions recurred (15%); 1 of these was an in situ tumor with cystic morphology and neuroendocrine differentiation and the other was pure invasive mucinous carcinoma. None of the lesions metastasized. Mucin-producing sweat gland carcinoma pathologically represents a continuum, from an in situ lesion to a classic, invasive mucinous carcinoma. Immunohistochemical evidence of neuroendocrine differentiation can be observed in all lesions and does not appear to have a prognostic significance, arguing against the utility of immunohistochemical subtyping of mucinous sweat gland carcinomas.