Amelanotic Conjunctival Melanoma

Conjunctival melanoma is a rare condition of the eye pigment predominantly affecting white adults. We describe a 32-year-old white man with an amelanotic malignant melanoma of the conjunctiva that is not associated with primary acquired melanosis (PAM) or melanocytic nevus. The patient presented with a 2-year history of nonpigmented vascularized nodules of the right eye. Results of hematoxylin and eosin (H&E) staining of the lesion showed an invasive nodule with vertical spreading, invasion of the substantia propria corneae, and ulceration. S100 protein was expressed in the cells of the invasive nodule. HMB45 protein was highly positive in the melanoma cells. The de novo amelanotic malignant melanoma of the conjunctiva we describe is an extremely uncommon tumor mainly affecting white adults.