Long-Term Clinical Results and Management following Vitrectomy in Undetected Retinoblastoma Eyes.

Introduction: Given the rarity of retinoblastoma and the consequences of accidental vitrectomy in the event of misdiagnosis, reporting on clinical experience in this area is important.

Objective: The aim of this study was to analyse the management and complications with a focus on local orbital recurrence and metastatic disease in 10 children vitrectomized in an undetected retinoblastoma eye.

Methods: This is a retrospective descriptive case series conducted in a single-centre referral university hospital.

Results: From October 1991 to June 2019, 10 patients with a vitrectomy in an unsuspected retinoblastoma eye were included in this study. The main preoperative diagnoses were unilateral inflammation with a suspected lymphoma, uveitis or toxocariasis in 5 cases, vitreous haemorrhage after trauma in 2 cases, and the last 3 were misdiagnosed with Coats disease, rhegmatogenous retinal detachment and congenital cataract. Mean age at surgery was 3 years, ranging from 14 months to 6 and a half years. Nine patients were suffering from unilateral retinoblastoma; these were enucleated and treated with 4-6 cycles of chemotherapy and/or radiation therapy. The sclerotomy sites were infiltrated with tumour cells in 3 cases. In 1 patient, the differential diagnosis of a malignant medulloepithelioma could not be excluded. One patient had bone marrow infiltration on initial presentation; all other patients are healthy without any signs of orbital recurrence or metastatic disease with a mean follow-up of 5.4 years.

Conclusion: In children, intraocular tumours, including retinoblastoma and medulloepithelioma, should be ruled out before pars plana vitrectomy is performed. If no doubtless preoperative diagnosis can be established, preoperative magnetic resonance imaging is mandatory. If a vitrectomy in a retinoblastoma eye has been performed, immediate enucleation of the eye with subsequent chemotherapy and orbital radiation is effective to avoid local recurrence and systemic metastases.