Primary mucinous adenocarcinoma of the eyelid.

Primary mucinous adenocarcinoma of the eyelid is a very rare tumor arising from the eccrine sweat gland. It is locally invasive with a high rate of recurrence following removal. Although uncommon, metastasis to regional lymph nodes does occur, and there have been several reports of more distant metastasis. This tumor is characterized by the secretion of mucin. This mucin usually forms into pools surrounding the clusters of tumor cells. Less commonly, the mucin may collect within the tumor cells and not be secreted into the extracellular spaces. Such a "mucin-poor" form of the tumor involving the eyelid was recently seen and is reported here. The clinical and pathologic characteristics of primary mucinous adenocarcinoma are presented and the modes of treatment are discussed.