Case Report: A Rosette-forming Glioneuronal Tumor in the Tectal Plate in a Patient with Neurofibromatosis Type I

We report the case of a 41–year-old female with neurofibromatosis Type 1 (NF1) who developed a rosette-forming glioneuronal tumor (RGNT) in the tectal plate. This tumor was diagnosed in 2002 when the patient presented with obstructive hydrocephalus, which was subsequently treated with a ventriculoperitoneal shunt and then an endoscopic third ventriculostomy. Initially thought to be a pilocytic astrocytoma, it was followed with serial magnetic resonance imaging (MRI) until tumor progression and development of a large fourth ventricular cystic component prompted resection via suboccipital craniotomy. Histological examination demonstrated an RGNT, a WHO Grade 1 tumor, with neurocytic rosettes, perivascular pseudorosettes, and elements resembling a pilocytic astrocytoma. Initially, the patient did well after her craniotomy, but postoperative complications set in that eventually led to her death. In this case report, we describe a relatively rare tumor that, despite its benign nature, leads to frequent complications and deficits due to its surgically challenging location. Along with previously reported examples, this cases raises the possibility of a causal relationship between NF1 and RGNT.