Unusual melanocytic nevi of the conjunctiva.
In one patient, an epithelioid cell nevus of the conjunctiva contained numerous large, unpigmented, mononucleated, binucleated, and multinucleated benign-appearing nevus cells with abundant cytoplasm and frequent intranuclear vacuoles. Despite their overall size, the cells manifested a low nuclear-cytoplasmic ratio. After a partial excision of the lesion, the remainder spontaneously regressed during a two-year period. Another patient's lesion was dominated by a proliferation of spindle nevus cells developing in a long-standing epibulbar nevus. The spindle cells were moderately pigmented, frequently located within walls of epithelial inclusion cysts, and had benign cytologic features. Finally, in a third patient with the cutaneous B-K mole syndrome, a dysplastic conjunctival nevus developed that featured intraepithelial, atypical melanocytic proliferation with superficial colonization of the substantia propria. This portion coexisted with a deeper, preexistent lesion in the substantia propria that was comprised of orderly nests of unpigmented cuboidal nevus cells surrounded by pigmented, spindle-shaped blue nevus cells--a so-called "mixed nevus."
D000293:Adolescent; D000328:Adult; D000368:Aged; D003228:Conjunctiva / Q000473:pathology*; D003230:Conjunctival Neoplasms / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000648:ultrastructure; D008854:Microscopy, Electron; D009508:Nevus, Pigmented / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D014792:Visual Acuity