Late Solitary Extraocular Recurrence From Previously Resected Iris Melanoma.

PURPOSE: To report on cases of late extraocular relapse of previously resected iris melanoma, without concurrent intraocular recurrence. DESIGN: Retrospective case series. METHODS: A retrospective chart review of 4 patients diagnosed with late subconjunctival relapse of previously resected iris melanoma. RESULTS: Three female patients and 1 male patient underwent iris tumor resection and presented to our service with suspicious conjunctival lesions at a median of 22 years later (mean: 21 years). None showed intraocular relapse. Treatment of the conjunctival tumors included excisional biopsy (n = 4), followed by cryotherapy (n = 3) and/or brachytherapy (n = 3). In all cases, histopathology confirmed malignant melanoma, with no intraepithelial component or associated melanosis. Genetic sequencing (n = 3) showed wild-type BRAF and NRAS in all. GNA11 mutation was found in 1 case. On array-based comparative genomic hybridization (n = 3), gain of 6p was found in 2 cases and gain of 8 in 2. Overall, findings were strongly suggestive of a diagnosis of late extraocular relapse from previously resected iris melanoma. In a median of 2.5 years (mean: 7.7 years) from the subconjunctival relapse, no further episodes of intraocular/extraocular recurrence were recorded, and all patients were free from distant metastasis. CONCLUSIONS: Patients undergoing iris melanoma resection are at risk of developing late solitary extraocular relapse even more than 30 years after surgery. In the absence of an intraocular component, diagnosis may be challenging, as tumors mimic a primary conjunctival lesion. Management by excisional biopsy followed by adjuvant therapy was successful, and histopathology and genetic analysis supported a diagnosis of extraocular uveal tumor spread rather than a primary conjunctival tumor.