Mucinous sweat gland adenocarcinoma of the eyelid - current knowledge of a rare tumor.

Purpose: To review the medical literature on mucinous sweat gland adenocarcinoma of the eyelid (MSA) and present two new cases.
Methods: Details of published case reports and small series (between 1971-2010) were evaluated and summarized including two patients diagnosed and treated at our institution. Data regarding age, gender, ethnicity, precise location, clinical presentation, treatment and follow up of each patient were collected.
Results: 25 reports describing 55 patients were found in the medical literature. The mean age was 61.3 years (30-87), 22(59%) were male and 28(80%) were Caucasian. In 23(44.2%) patients the lesion was in the lower lid, in 20(38.5%) in the upper lid, in 3(5.7%) involving both lids and in 6(11.6%) in a canthus. In 12(21.8%) patients a lesion with a benign diagnosis was previously excised from the same location. In 2 of them histological re-examination resulted in a diagnosis of MSA. Intraorbital involvement was found in 2(3.6%) patients. Regional lymph node metastasis was found in 2(4.4%) patients. Surgical excision was the treatment of choice using Mohs' micrographic-controlled excision technique in recent years. Radiotherapy was applied to 2 patients with clinical resolution in 1. Recurrence of the tumor was reported in 14(30%) patients.
Conclusions: MSA is a rare tumor of the eyelid with no clinically distinguishing features. It should be suspected particularly with recurrent eyelid lesions and must be differentiated from metastatic disease. The tumor may extend into the orbit and metastasize regionally. Surgical removal with continued regular follow-up examination is the treatment of choice.