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 females and one male underwent iris tumour resection and presented to our service with suspicious conjunctival lesions at a median of 22 years later (mean: 21). None showed intraocular relapse. Treatment of the conjunctival tumours 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 wildtype BRAF and NRAS in all. GNA11 mutation was found in 1 case. On array CGH (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) from the subconjunctival relapse, no further episodes of intra/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 over 30 years after surgery. In the absence of an intraocular component, diagnosis may be challenging, as tumours 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 tumour spread rather than a primary conjunctival tumour.