Alveolar Rhabdomyosarcoma of the foot metastasizing to the Iris: report of a rare case

BACKGROUND: Intraocular iris rhabdomyosarcoma is extremely rare, and in the 3 cases reported to date occurred as the primary site of tumour growth. We report a case of rhabdomyosarcoma of the foot metastasizing to the iris. CASE PRESENTATION: An 18-year-old white female was referred to the London Ocular Oncology Service for management of a metastatic rhabdomyosarcomatous deposit in the iris, a metastasis from alveolar rhabdomyosarcoma of the foot. She was diagnosed nearly 2 years earlier with the primary sarcoma with extensive systemic spread and treated by resection of the foot lesion and chemotherapy, and achieved a partial remission. The left iris deposit was noted while she was receiving systemic chemotherapy, heralding a relapse. However, anterior uveitis and raised intraocular pressure developed and she was referred to our service for further management. A left iris secondary rhabdomyosarcoma deposit was noticed and in addition a lacrimal gland mass, as indicated by ultrasound B scan of the eye and orbit. The patient was treated with external beam radiotherapy to the globe and orbit, but died 2 months after treatment completion. CONCLUSION: Rhabdomyosarcoma of the iris is very rare and was previously documented only as a primary malignancy in this location. We report that secondary spread to the iris can also occur, in this case as the first sign of widely disseminated systemic relapse.