To report a case with agressive massive choroidal invasion by Retinoblastoma in already treated patient.

A case report

A 24-month-old girl was diagnosed with bilateral retinoblastoma who has been treated with systemic chemotherapy and intra-arterial chemotherapy (IAC) for left eye. At 4 years of age, 6 months after last treatment, fundus examination showed regressed tumor in both eyes without any signs of activity. Three months later,a recurrent lesions was found in inferior quadrant of left eye.She underwent 2 cycles of monthly IAC adjunctive with laser thermotherapy. The patient found intra-ocular pressure (IOP) rising. One month after last IAC, surprisingly, we found a huge infero-nasal yellowish mass and 4 quadrant retinal detachments.Under close observation, 2 weeks later, despite our decision for doing Ru106 plaque radiotherapy, indirect ophthalmoscopy showed rapidly growing peripheral choroidal mass and ultrasound biomicroscopy revealed a mass lesion involving the choroid/ciliary body with dimensions of 18 ×18× 16 mm capsule. Clinical view of the mass was not similar to the classic recurrence of RB therefore, due to high IOP, total RD and unresponsive very rapid growth intraocular lesion, enucleation was considered for her. Histopathology examination demonstrates extensive involvement of choroiod, ciliary body and angle with poorly differentiated retinoblastoma.

. The sudden appearance of a dome-shaped mass with rapid growth in undergoing treatment patients should be suspect to choroidal involvement.