Small Choroidal Melanoma Revealed by a Large Extrascleral Extension

Abstract

Aims: Orbital extraocular extension of choroidal melanoma is very rare with small melanomas. We report the case of a patient whose small choroidal melanoma was initially overlooked and was revealed by a large extrascleral extension. Methods: A 48-year-old Caucasian woman presented with sudden total visual loss in the right eye. Multicolor imaging of the fundus showed right optic disc edema and an orange and green lesion near the optic disc. The diagnosis of unilateral optic neuritis was made. Magnetic resonance imaging showed an extraocular mass adjacent to the optic nerve; on ultrasound, this mass was acoustically hollow and a small intraocular component was visible. Results: Choroidal melanoma with a large extrascleral extension was diagnosed (T4eN0M0, stage IIIC according to the AJCC 7th TNM classification, 2010). The size of the extraocular nodule was 13 × 5 mm. Treatment consisted of enucleation followed by adjuvant external beam orbital radiotherapy. Tumor analysis showed a mixed cell type melanoma with monosomy 3. The patient developed liver metastasis 10 months after local treatment. Conclusion: Extraocular extension of choroidal melanoma can occur with small lesions. Prognosis is generally poor according to AJCC TNM. This case is a reminder that fundus examination may reveal the nature of the mass in some patients with orbital tumors.

MR imaging characteristics of uveal melanoma with histopathological validation

“…It should be diagnosed in order to be taken into account in the treatment plan. We found extrascleral extension in 7% of the UM, consistent with current literature [ 27 , 29 – 31 ]. Interestingly, in the present study, all observed extrascleral extensions occurred in small tumors with a maximum prominence of 4.8 mm, although in general, it occurs more commonly in medium or large tumors [ 29 , 32 ].…”

“…We found extrascleral extension in 7% of the UM, consistent with current literature [ 27 , 29 – 31 ]. Interestingly, in the present study, all observed extrascleral extensions occurred in small tumors with a maximum prominence of 4.8 mm, although in general, it occurs more commonly in medium or large tumors [ 29 , 32 ]. Extrascleral extension often develops along scleral canals, via perivascular or perineural invasion.…”

“…Extraocular growth is associated with an increased rate of orbital recurrence and worse survival [ 29 , 30 ]. It should be diagnosed in order to be taken into account in the treatment plan.…”

“…Extrascleral extension often develops along scleral canals, via perivascular or perineural invasion. Therefore, the scleral underlying the tumor does not need to be invaded and the extrascleral tumor can even be located further away from the intraocular tumor [ 29 , 30 ]. We had no false-positive cases with MRI, and one false-negative case where the extrascleral extension was 1.1 mm and anteriorly located.…”

Application of Multimodal and Molecular Imaging Techniques in the Detection of Choroidal Melanomas

“…When a choroidal melanoma involves the optic nerve, the fundus may have a similar manifestation of optic neuritis; MRI may show the tumor as a mass adjacent to the optic nerve. However, ultrasound evaluation can show the absence of an echo and reveal intraocular components, thus aiding in diagnosis of the mass ( 40 ). Nevertheless, for small choroidal melanomas, the specificity of ultrasound involving subretinal fluid is low, because such tumors cannot be distinguished from retinal thickening, cystic changes, and pigment epithelial detachment ( 41 ).…”