Primary Orbital Melanoma: A Systematic Review of Clinical Characteristics, Management and Outcomes

To evaluate the clinical characteristics, management, and outcomes for histopathologically confirmed primary orbital melanoma (POM).

A systematic review was conducted in accordance with PRISMA guidelines and registered with PROSPERO. Studies reporting 1 or more patients with histopathologically confirmed POM and extractable data were included; secondary orbital involvement and nonoriginal reports were excluded. Data were extracted for demographics, clinical features, treatment, and outcomes. Tumors were classified as either melanocytosis/nevus-associated (MATs) or de novo melanomas. Outcomes for local recurrence, metastasis, overall survival (OS), and recurrence-free survival (RFS) were analyzed using Kaplan-Meier methods.

A total of 112 patients were included, of whom 49 (44%) had POMs that arose de novo, 34 (30%) were MATs, and the remainder were unclassified. Patients with MATs were slightly younger (40.1 vs. 47.9 y; P=0.078) and had shorter symptom duration (5.3 vs. 13.1 mo; P=0.158). Globe-sparing surgery was performed in 47% of cases, exenteration in 53%, and adjunctive radiotherapy in 37%. At a mean follow-up of 26.9 months, local recurrence occurred in 21% and metastasis in 39%. Estimates of 5-year OS showed a nonsignificant trend that favored MATs (74% vs. 44%; P=0.058), whereas recurrence-free survival was longer with melanocytosis-associated tumors (P=0.048). Adjuvant radiotherapy was associated with improved survival (HR=0.23; 95% CI: 0.08-0.66; P=0.006).

POM is a rare malignancy. MATs may represent a distinct subset with more favorable outcomes, although interpretation is limited by the many small and heterogeneous data sets. Globe-sparing management appears to be valuable in some cases.