[Primary signet ring cell carcinoma of the eccrine sweat gland in the eyelid. Immunohistochemical and ultrastructural study of a case].

We report a case of a 45-year-old woman who exhibited a primitive eccrine sweat gland carcinoma of the eyelid. Histological study showed cellular proliferation with an Indian file pattern and some signet ring cells with sialomucin secretion. Immunohistochemical study demonstrated these cells to be positive with the anticytokeratin, anti-EMA, anti-HMFG, antiestrogen receptor and antiprogesterone receptor antibodies. Ultrastructural study showed intracytoplasmic vacuoles with numerous microvilli at the apical side. Differential diagnosis with a metastasis from a mammary adenocarcinoma is difficult and a complete staging is necessary to confirm the primitive origin of the tumor. The behavior of this tumor is marked by locoregional recurrence.