Two distinctly located primary orbital melanomas following evisceration for congenital corneal staphyloma: a case report and brief literature review.

PURPOSE: To report an unusual case of two distinct primary orbital melanomas emerged 9 years following evisceration for congenital corneal staphyloma and implantation of a MEDPOR® prosthesis.

CASE DESCRIPTION: A 14-year-old female with congenital blindness and progressive right globe enlargement since birth, accompanied by multiple cutaneous blue nevi, initially underwent right eye evisceration with MEDPOR® implant placement in 2012, revealing congenital corneal staphyloma and proliferative vitreoretinopathy on histopathology. Nine years later, she presented with chronic right eye tearing and intermittent bloody discharge. Examination revealed a prominent scalp blue nevus with satellite lesions, mild orbital implant protrusion, conjunctival congestion, and a subconjunctival black mass. MRI identified a 1.9 cm T1-slight hyperintense, T2-hypointense mass superior to the implant, with inferior rectus thickening. Surgical excision yielded two masses: a 41 mm inferonasal lesion (partially pigmented, unencapsulated) and a 20 mm superior-posterior black, spherical mass. Histopathology confirmed orbital malignant melanoma, with tumor cells positive for S-100 (3+), Melan-A (3+), and HMB-45 (2+). NGS revealed no pathogenic variants, and PET/CT showed no metastasis. She subsequently underwent postoperative radiotherapy and maintains good overall health until June 2025.

DISCUSSION: This article reports a case of primary orbital melanoma presenting as two tumors within a single orbit following evisceration, with a focus on elucidating the origin of tumor cells and their relationship with pigmented nevi and orbital implants.

CONCLUSION

Blue nevi may represent an underrecognized risk factor for primary orbital melanoma, and enucleation may be preferable to evisceration for idiopathic corneal staphyloma to reduce melanoma risk.