Every Rose Has Its Thorn

The MRI brain showed multiple T1 hypointense T2 hyperintense cystic lesions within the posterior fossa involving the cerebellar vermis, right cerebellar hemisphere, and brainstem. Possible scolices were identified within multiple cysts on T1 images, leading to a high suspicion for parasitic infection, specifically neurocysticercosis (NCC). MRI of the spine showed similar intramedullary lesions extending from brainstem to involve the upper cervical spinal cord. CT of the head demonstrated a single area of calcification in the right cerebellum. An extensive infectious disease, auto-immune, and paraneoplastic evaluation was pursued. Consultation with neurocysticercosis experts at the CDC was obtained. The possibility of coenurosis secondary to Taenia multiceps, T. serialis, T. brauni, or T. glomerata was considered as well. Infectious workup for Echinoccocus, Toxoplasmosis, and TB was negative. Stool ova and parasites was similarly negative. Serum testing for NCC with enzyme-linked immunoelectrotransfer blot (EITB) was sent to the CDC. Auto-immune and paraneoplastic work up were negative. Treatment for a presumed parasitic infection with anti-helminthic therapy after steroid pre-treatment was entertained. However, after further discussion with the CDC, this option was reevaluated due to the high lesion burden and potential massive inflammatory response. There was also growing skepticism for a parasitic etiology of the lesion, a biopsy was obtained for definitive diagnosis. Pathology was diagnostic for a low grade glioneuronal tumor with characteristics suggestive of a rosette-forming glioneuronal tumor (RGNT). Some cells showed oligodendroglioma-like features, however this was ruled out based on the absence of 1p 19q codeletion on chromosomal microarray. RGNT is a glioneuronal tumor that may show oligodendroglioma-like areas and is found in the fourth ventricle, and rare RGNT cases have been reported with similar multi-loculated gross and radiologic morphology. However, this potential diagnosis could not be definitively established on histopathology as the tumor failed to show characteristic rosettes with synaptophysin positive cores.