Secondary orbital melanomas: analysis of 15 cases

Orbital melanomas comprise a heterogeneous group of pigmented tumours originating from melanocytes of the ophthalmic tissues, or represent distant metastases of cutaneous melanomas to the orbit. They can be classified into primary and secondary orbital melanomas. Whereas primary orbital melanomas are extremely rare, secondary orbital melanomas are seen more often and usually represent massive extrascleral extensions of uveal melanomas. Their diagnosis is difficult and controversy exists both about the treatment policy and regarding the prognosis. In an effort to clarify some of the aspects of the biological behaviour of these intriguing lesions, we retrospectively reviewed all orbital melanomas treated in our departments during the last eight years. The records of 15 patients with massive secondary orbital melanomas treated surgically were reviewed and analysed. Eleven of the patients were female and four were male. The mean age at the time of surgery was 68 years. Presenting features included unilateral orbital mass, often with painless proptosis, conjuctival bleeding, acute glaucoma crisis, decreased visual acuity and intermittent diplopia. The site of origin was the uveal tract in nine cases, the conjunctiva in three, the eyelids in two and the skin of the lower extremity in one patient. All patients were treated surgically with various types of orbital exenteration. Additional treatment included radiotherapy and chemotherapy. Two patients died from intracranial extension of the disease and 10 died from distant metastases. Three patients are alive with no evidence of disease. The longest survival was 33 months and the mean survival was 16.6 months. Early diagnosis and proper management of ocular melanoma prevents orbital extension and prolongs patient survival. Surgical treatment of secondary orbital melanoma with or without adjuvant radiotherapy and/or chemotherapy does not seem to improve patient survival when compared with conservative treatment used in other reports. However, orbital exenteration is effective for local control of the disease.