Solitary Intratarsal Blue Nevus.

A 42-year-old woman presented with a small pigmented lesion of the palpebral conjunctiva that had been present for a few months. Because of the possibility of melanoma, the lesion was resected. Microscopic examination displayed an intratarsal blue nevus at the level of the meibomian glands comprised of bland nonpigmented and pigmented cells that enveloped a sebaceous gland and its ducts. The cells were of admixed spindle and epithelioid configuration and were immunoreactive for Melan-A. The Ki67 proliferative marker was negative in these cells, contrasting with the epithelium of the overlying conjunctiva and the sebaceous ducts, and thereby militating against the diagnosis of melanoma. Clusters of melanophages were also present. Although an intratarsal blue nevus has been described as a component of a combined nevus, the current lesion demonstrates the occurrence of a sole tarsal blue nevus. Palpebral pigmented lesions should be customarily excised because many are melanomas.