Orbital melanoma with calcification: A diagnostic dilemma

Area of Science:

• Ophthalmology
• Oncology
• Pathology

Background:

• Primary orbital melanoma is a rare malignancy with diverse clinical presentations.
• Orbital tumors can present with symptoms like proptosis and decreased vision, mimicking other orbital pathologies.

Observation:

• A 28-year-old female presented with proptosis and decreased vision, initially diagnosed as optic nerve sheath meningioma via CT scan.
• The patient opted for observation, but experienced worsening proptosis and vision loss over six months.

Findings:

• Surgical exploration revealed a pigmented mass encasing the optic nerve, confirmed as malignant melanoma via histopathology.
• Metastatic workup was negative, and the patient underwent a left eye lid-sparing exenteration.

Implications:

• This case highlights the importance of considering orbital melanoma in the differential diagnosis of rapidly growing orbital masses, especially those mimicking meningioma.
• A high index of suspicion is necessary for prompt diagnosis and management of primary orbital melanoma to improve patient outcomes.