Rosette-forming glioneuronal tumor mimicking intraventricular tuberculoma in a 2-year-old: a case report

Introduction. Rosette-forming glioneuronal tumor (RGNT) is a rare WHO grade I central nervous system neoplasm predominantly affecting adolescents and young adults. Originally described in the fourth ventricle, RGNTs have also been reported in other CNS locations, including the third and lateral ventricles, hypothalamus, spinal cord, and cerebrum. RGNTs are characterized by a biphasic architecture composed of glial and neurocytic elements, including true rosettes and perivascular pseudorosettes. Due to overlapping imaging features with other intraventricular pathologies – particularly in regions endemic for tuberculosis – accurate diagnosis can be challenging, especially in pediatric patients. Case presentation. We report a case of a 2-year-old female presenting with vomiting and altered consciousness. MRI revealed a well-circumscribed, enhancing mass in the right lateral ventricle associated with obstructive hydrocephalus. The initial radiological impression favored intraventricular tuberculoma. Surgical resection via right parietal craniotomy was performed. Histopathological examination showed a biphasic tumor with neurocytic rosettes and a glial component. Immunohistochemistry was positive for synaptophysin and GFAP, and negative for Olig2, EMA, and chromogranin, with a low Ki-67 index (2–4%), confirming the diagnosis of RGNT. Conclusion. This case underscores the importance of considering RGNT in the differential diagnosis of pediatric intraventricular masses, especially when imaging mimics infectious granulomas. Accurate histopathological and immunohistochemical evaluation is critical for diagnosis and management. Given its rarity, particularly in very young children and in supratentorial locations, reporting such cases contributes valuable insight into the expanding clinical and anatomical spectrum of RGNT.