Immunohistochemical analysis of cytokeratin expression in multiple eccrine hidrocystoma

The histologic diagnosis as eccrine hidrocystoma may contain some other cysts which do not originate from the eccrine sweat glands. Some authors have suggested that true eccrine hidrocystoma does not exist. However, multiple eccrine hidrocystoma (Robinson type) is a distinct clinical entity which is characterized by multiple translucent papules around the eyelids which appear in warm weather. Cytokeratin expression in 8 cases of multiple type of unequivocal eccrine hidrocystoma was analyzed immunohistochemically. Immunoreactivities in our cases were similar to those of eccrine dermal ducts. Therefore, we confirmed that these tumors were derived from the eccrine dermal duct, not from the other appendages, and that true eccrine hidrocystoma exists.