Case of primary orbital melanoma causing Recurrent Orbital Hemorrhage in elderly patient

After 6 months, complete ophthalmologic examination was performed again; VA was 20/20 OU, and there was no remaining proptosis. Two weeks later, the patient presented to the ED for another episode of acute, painless, right proptosis, and the VA had decreased to 20/40OD. MRI showed a right retrobulbar hemorrhage. Systemic corticosteroid therapy was again prescribed for 48 hours with rapid resolution of the visual impairment but incomplete resolution of the proptosis.

One month later, the patient presented to ophthalmology department. The VA was 20/20 OU, with a persistent, mild, nonreducible, nonpulsatile proptosis unrelated to Valsalva maneuver but associated with extraocular movement limitation in upgaze. A repeated MRI was performed.

Patient was diagnosed having Recurrent retrobulbar hemorrhage owing to an orbital tumor: a primary orbital melanoma. Additional imaging, including a computed tomography and positron emission tomography scan was done.

The differential diagnosis of a retrobulbar hemorrhage includes orbital trauma; recent orbital, eyelid, lacrimal, or sinus surgery; orbital vascular anomalies; Valsalva-related hemorrhage in a patient with sinonasal carcinoma; and primary orbital tumor ormetastasis. In this patient, there was no history of recent trauma or orbital or periorbital surgery. This presentation—recurrent retrobulbar hemorrhage associated with orbital mass effect over several weeks and restriction in upgaze—suggested an orbital tumor history but was not specific enough to eliminate an orbital vascular anomaly.

MRI was needed to differentiate between a vascular or tissular lesion. The isointensity of the lesion in T1- and T2-weighted images was in favor of a tissular lesion; avascular or cystic lesion would be hyperintense on T2-weighted images. These findings supported a retrobulbar tumor surrounding the optic nerve.

Additional imaging was needed for disease staging and treatment planning. Computed tomography (CT) imaging of the orbital region can show bony involvement (osteolysis), which, if present, can help in surgical planning. CT imaging of the cranial, neck, thoracic, and abdominal regions can show primary disease or metastasis. Positron emission tomography (PET) imaging can assess the metabolic uptake of the orbital lesion and is more sensitive than CT imaging in cancer staging. Angiography is not helpful as an initial imaging modality; orbital vascular anomalies are unlikely owing to the tissue like aspect of the lesion.

In this case, CT imaging showed no osteolysis, and PET imaging revealed hypermetabolism of the orbital tumor without the presence of other hypermetabolic lesions. An inferior transconjunctival orbital biopsy was performed. Histologic examination confirmed a primary melanoma. This biopsy should be done after cancer staging imaging so as not to miss another, more accessible site of biopsy.

Nonmetastatic malignant melanoma treatment involves complete surgical removal with safety margins. Evisceration or enucleation were not an option in this patient as the tumor was primarily intraorbital and not intraocular. Ultimately, eyelid-sparing exenteration was performed, followed by radiotherapy. The primary meningeal melanoma originated in the optic nerve, developed in the posterior orbit, and infiltrated the oculomotor muscles, orbital fat, and sclera without intraocular extension. Genetic testing was positive for the GNAQ variant and negative for the BRAF variant. Unfortunately, the patient developed a hepatic metastasis diagnosed on postradiotherapy imaging. The patient died a few months later.

Source: Alexis Mathieu; Romain Nicot; Matthias Schlund; JAMA Ophthalmology Clinical Challenge

doi:10.1001/jamaophthalmol.2022.2875