[A case of Merkel cell carcinoma of the eyelid].

An 84-year-old man with Merkel cell carcinoma in the right upper-eyelid is reported. The patient presented with a rapidly growing, reddish-purple, solid tumor with a relatively well-defined margin in the skin of the lid. Increased neuron specific enolase content in the blood returned to normal several months after resection of the tumor and 70 Gy postoperative cobalt radiation. Histopathologic examination of the resected specimen revealed that the tumor was limited by intact epidermis and occupied by moderate-sized, round malignant cells with marked mitoses and scant cytoplasm. The neoplastic cells were positively stained by labeled antibodies for neuron specific enolase, keratin and epithelial membrane antigen. Electron microscopic examination showed abundant perinuclear microfilaments and dense core granules.