Objective: To evaluate the clinical features, diagnostic methods and treatment of extraocular extension of choroidal melanoma.
Methods: It was a retrospective case series study. The records of 12 consecutive cases with extraocular extension of choroidal melanoma confirmed by pathologic examination were analyzed with special attention to the case histories, clinical manifestations, imaging findings, treatment and follow up results.
Results: Four patients were misdiagnosed as glaucoma. Another 4 patients were confirmed the diagnosis of melanoma and 3 of them received the operations of transscleral local resection. The common clinical manifestations included: impaired vision, exophthalmos, blepharoptosis, limited ocular motility, conjunctival hyperemia, and increased ocular or orbital pressure, etc. Characteristic sign was raised mass on the surface of sclera. All cases underwent orbital MRI preoperatively, 6 underwent ocular B-scan echography, and 6 underwent orbital CT scanning to evaluate for extraocular extension of tumor. Typical ultrasonography revealed the discontinued ocular wall and an intraocular mass with a continuous hypoechoic extraocular mass. In some cases the extraocular mass showed hypoechoic with medium echo area. CT scan showed a well-defined homogeneous intraconal mass connecting with intraocular lesion in 6 cases, which could infiltrate eye or optic nerve. The MR signal features of intraocular tumors with extraocular extension showed 4 patterns in all patients. The typical pattern was the tumor showed hyperintensity on T(1) and hypointensity on T(2)-weighted image. The maximum diameter of extraocular tumor was measured over 4 mm in 9 cases. MRI was useful for demonstrating multiple extraocular lesions, remote metastatic lesion or micro extraocular tumor, of which minimal diameter was 3 mm in our cases. Orbital exenteration was performed in 11 cases and ocular enucleation with excision of extraocular tumor was in 1 cases. Microscopic examination showed the epithelioid-cell-type tumors were the most common. The tumor extended out of the eye by three types of way in our cases. Follow-up ranged from 1 to 5 years in 8 cases, who underwent chemotherapy, radiotherapy or interferon. Six cases had no recurrences and general health. Death and metastasis was respectively recorded in one case.
Conclusions: Delayed treatment could induce the growth of choroidal melanoma to the stage of extraocular extension, which has few specific clinical manifestations. The combination of multiple imaging examinations was helpful for the correct diagnosis. Surgical operation with adjunctive therapies could partly reduce recurrence and metastasis of melanoma.