Medulloepithelioma: invasive versus noninvasive diagnostic methods and their impacts on outcome.

Purpose: The purpose of this study was to report a case of a 34-month-old patient who presented with leukoria and underwent a vitrectomy and vitreous biopsy at an outside hospital followed by definitive enucleation for a nonteratoid medulloepithelioma and to review the literature regarding metastatic rates for this tumor after intraocular surgery.
Methods: The authors reviewed the clinical, histopathologic, and neuroimaging records in the unusual case of a child with medulloepithelioma who had previously undergone pars plana vitrectomy and vitreous biopsy. An in-depth literature search was performed for patients with medulloepithelioma with prior biopsy or surgery.
Results: Clinical examination showed a subluxed cataractous lens and neovascular glaucoma. Ultrasonography showed a large, cystic lesion with high reflectivity. Enucleation was performed, and histopathologic analysis showed a diffuse nonteratoid medulloepithelioma.
Conclusion: Metastasis in medulloepithelioma is very rare. A systematic review of cases of patients with medulloepithelioma undergoing invasive intervention indicated that some patients subsequently developed metastases. Such procedures should be avoided to prevent orbital seeding or creating tracts for tumor migration and ultimate extraocular relapse.