Malignant medulloepithelioma mimicking retinoblastoma — clinical and morphological case analysis and cell culture experience

Abstract

The paper presents clinical and morphological case analysis of primary intraocular malignant medulloepitelioma (medulloblastoma) of rare localization (central part of the retina with optic nerve involvement) that simulated retinoblastoma in a 2-year-old child. Histological features of the tumor are given in details (tubular and mesh structures of the tumor, rosettes, ribbons, cells with hyperchromic nuclei, and cellular polymorphism). An experience of creating a primary intraocular malignant medulloepitelioma cell culture, as yet exclusive in the Russian Federation, is described. Culture sensitivity for particular drugs (oxaliplatin, irinotecan, ifosfamide, and ascorbic acid at different concentrations) was evaluated by MTT-assay. Of the four products, IC50 (3.3 mg/ml) was obtained only for ascorbic acid. Despite the relative rarity of primary intraocular malignant medulloepitelioma, its differential diagnosis should be carried out, with retinoblastoma in mind in the first place. The obtained data on the effectiveness of ascorbic acid against intraocular malignant medulloepitelioma cells can be used to supplement the existing chemotherapeutic protocols in pediatric ocular and neuro-oncology.