Neurothekeoma palpebrae: A report of 3 cases.

Neurothekeoma palpebrae is the diagnostic term used to describe nerve sheath myxoma or neurothekeoma of the eyelid. Although these tumors are not uncommonly found in the head and neck region, eyelid involvement is very uncommon. We present 2 cases of cellular neurothekeoma and 1 case of nerve sheath myxoma occurring in the eyelid. Patient 1 was a 13-year-old girl with a left upper eyelid lesion of 6-months duration. Microscopic examination disclosed a cellular neurothekeoma with mild myxoid change and osteoclast-like multinucleated cells. Tumor cells infiltrated the orbicularis oculi muscle. The tumor cells were immunopositive for NKI.C3, CD34, and focally for S-100 protein. Multinucleated cells were reactive to CD68. Mart-1, smooth muscle actin, CD31, keratin, desmin, myogenin, synaptophysin, and neurofilament protein (NFP) were negative. Patient 2 was a 4-year-old girl with a left upper eyelid lesion diagnosed clinically as a chalazion. The lesion was incised. Five months later, the patient returned with a firm 5.5-mm nodule at the site. Excision revealed cellular neurothekeoma invading the orbicularis oculi. Tumor cells were NKI.C3 immunopositive and S-100 protein negative, and the multinucleated cells were CD68 positive. Patient 3 was a 70-year-old woman with a 10-year history of a subcutaneous right lower eyelid nodule which had recently changed color. The excised specimen demonstrated a hypocellular, well-circumscribed myxoid tumor surrounded by a thin rim of fibrous connective tissue. Tumor cells contained moderate amounts of eosinophilic cytoplasm with irregular, hyperchromatic nuclei. Nucleoli and mitotic figures were not apparent. Tumor cells were NKI.C3 negative, and S100 protein and glial acidic fibrillary protein positive, consistent with a nerve sheath myxoma. Including our 3 cases, 10 cases of nerve sheath myxoma and neurothekeoma occurring in the eyelid have been reported the English language literature. Although uncommon, these lesions should be kept in the differential diagnosis of eyelid tumors that can masquerade as chalazia.