Giant conjunctival melanoma with rich vascularization causing persistent bleeding.

The present study reported a rare case of persistent bleeding caused by conjunctival melanoma containing abundant vascular channels. A 44-year-old Japanese woman presented with a left upper eyelid nodule in February 2023. A pigmented conjunctival mass was present in the upper palpebral conjunctiva. Enhanced computed tomography demonstrated marked enhancement in the left eyelid in the artery phase, indicating hemangioma. The patient suffered blunt trauma to the face in May 2023 and continuous bleeding occurred. Doctors in the emergency room attempted hemostasis by diathermy and suture, but the bleeding could not be stopped. The patient eventually underwent emergent orbital exenteration of the left eye. At high magnification of the histology sample of the bleeding site, small-to-large vascular channels with various vascular lumens made up of endothelial cells within the conjunctival melanoma tissue could be observed. The tumor cells were positive for SOX10, Melan A, S100 and HMB45. We herein propose a novel variant of conjunctival melanoma with rich vascularization, clinically causing persistent bleeding.