Treated Choroidal Melanoma with Late Metastases to the Contralateral Orbit

Abstract

Choroidal melanoma is the commonest adult primary intraocular tumour, 1 and usual sites of secondary spread are to liver, bone and lung. Although delayed recurrence of ipsilateral orbital melanoma is well documented, metastasis to the contralateral orbit is a rarely encountered phenomenon. We describe a case of metastatic spread to the contralateral orbit in a patient 12 years after proton beam radiotherapy of choroidal melanoma. Keywords: choroidal melanoma, metastases, orbit, proptosis Case ReportA 73 year old lady attended ophthalmic outpatients in 1993 describing photopsia in her left pseudophakic eye. Snellen visual acuity was right eye 6/9, left eye 6/18. Dilated fundoscopy demonstrated an elevated, pigmented mass in the superotemporal quadrant of her left eye approximately 3 disc diameters from the optic nerve head. The clinical appearance was consistent with malignant melanoma of the choroid and ultrasound (U.S.) B scan demonstrated a lesion of 14 mm width and 7 mm height. Haematological markers, chest radiography and liver ultrasound were all normal. Following referral to a national centre for ocular oncology, a course of proton beam radiotherapy was instituted and the patient attended for regular follow up. Tumour dimensions were repeatedly assessed and found to be stable and regular clinical review until June 2005 demonstrated no change in the fundal mass, or anterior extension in relation to scleral markers inserted at the time of proton beam radiotherapy. No scleral extension was evidenced on thorough orbital ultrasound, nor was there any evidence of systemic involvement.In July 2005, the patient now aged 85, presented with sudden, non-axial, painless proptosis of the right globe associated with upper lid ptosis. There was 2 mm proptosis and medial and inferior displacement of 2 mm and 8 mm respectively (Fig. 1). There was associated oedema and erythema of the soft tissue but no signifi cant pain or heat on palpation. Orbital CT displayed a well-defi ned, non-enhancing, rounded mass lesion in the superolateral right orbit extending medially and inferiorly into the intraconal space displacing the superior rectus and optic nerve (Fig. 2). Histology of the biopsied lesion showed a necrotic malignant melanoma composed of epithelioid cells containing large nuclei with prominent nucleoli and a moderate amount of pink cytoplasm. Focally the cells contained melanin pigment. These expressed the melanocytic markers melan A and HMB 45 on immunohistochemistry but were non-reactive to S100 and CAM 5.2. (Fig. 3).Systemic evaluation with CT scan of chest, abdomen and pelvis showed multiple metastatic deposits in the liver and at least one in either lung base. Referral to the regional oncology unit ensued and palliative chemotherapy of oral Temozolomide was commenced. Additional treatment with oral dexamethasone 4 mg daily greatly improved the right orbital tissue swelling and globe proptosis and the patient remained comfortable for 6 months. She died one year following this presentation. DiscussionOrbita...

Orbital melanocytoma: When a tumor becomes a relieving surprise

“…Metastases from choroidal melanoma to the contralateral orbit are rarely reported. 11 Although, orbital metastases have been described following systemic spread from choroidal melanoma, 12 there are few reports about orbital secondary lesions to be the first sign of distant spread. 11 , 13 , 14…”

Adjuvant External Beam Radiotherapy Following Enucleation of Eyes With Extraocular Extension From Uveal Melanoma

“…As one patient presented with systemic metastasis within a month of enucleation, it is possible that this orbital tumor may have been a local metastasis rather than extraocular extension directly from the tumor, as metastasis of treated choroidal melanoma to the contralateral orbit have been previously reported. [38][39][40] Unfortunately, due to the limitations pertaining to the standardized documentation of metastatic status, we were unable compare the risk of distant metastasis between the groups. Likewise, as the cause of death was not known in many patients, we could only report all-cause mortality and overall survival.…”