[Case of corneally displaced malignant conjunctival melanoma]

We studied the clinicopathologic characteristics in a patient with malignant conjunctival melanoma associated with corneal invasion.

A 62-year-old man had a small melanocytic lesion of the inferior palpebral conjunctiva. Previously he had undergone excisional biopsy and was diagnosed as having melanocytic hyperplasia without cytological atypia at an other hospital. He developed recurrence and was referred to us. The pigmentary lesion was observed in the entire inferior palpebral conjunctiva. Biomicroscopic examination revealed that there was a granular pigment lesion in the cornea. The patient was diagnosed as having conjunctival melanoma with corneal invasion and treated with orbital exenteration and chemotherapy in our hospital. Clinicopathologic tests revealed malignant melanoma cells invading through the bulbar conjunctiva and into the cornea. Ultrastructural study by electron microscopy of the pigmented tumor cells in the cornea showed several lobations of the nuclei, a large active-appearing nucleolus, and an aberrant granular melanosomal morphology.

The infiltration of palpebral malignant conjunctival melanoma was limited to the epidermis of the cornea.