Merkel cell carcinoma of the eyelid and periocular tissues.

Five patients had eyelid and periocular Merkel cell carcinoma. The tumor was located on the left lower eyelid in two patients, the left upper eyelid in one patient, the right upper eyelid in one patient, and was metastatic to the right outer canthus in one patient. The mean duration of symptoms was approximately four months. The diagnosis of Merkel cell carcinoma was not suspected clinically in any of the four primary eyelid cases, but was only established on histopathologic examination of biopsy specimens. Light microscopy disclosed carcinoma with small primitive cells in all five tumor biopsy specimens. Immunohistochemical studies showed neuron-specific enolase and keratin and transmission electron microscopy demonstrated neurosecretory granules typical for Merkel cell carcinoma. All five patients in this study were treated with wide surgical excision of the eyelid tumors with intraoperative frozen-section monitoring of the margins of resection. The left lower eyelid Merkel cell carcinoma spread to the preauricular lymph node in one patient. This patient subsequently died of metastatic Merkel cell carcinoma. One patient with metastatic right outer canthus Merkel cell carcinoma received radiotherapy (6,550 cGy). Eyelid Merkel cell carcinoma has the potential for recurrence and metastatic spread. We recommend lifetime follow-up for patients treated for eyelid Merkel cell carcinoma.