Solid intraventricular papillary glioneuronal tumor: magnetic resonance imaging findings with histopathological correlation

Intraventricular papillary glioneuronal tumor with high proliferation index and CD117 positivity: Report of an atypical case and review of literature

Papillary glioneuronal tumors are rare neoplasm, accounting only <0.02% of all intracranial tumors. They are generally low grade usually occur in the temporal lobe near the third ventricle. We report an extremely rare case of intraventricular tumor with a high proliferation index. CD 117 expression found in our case is the first study to the best of our knowledge to be described in these tumors. The clinical and diagnostic significance of this finding is subject to further studies.

Acute presentation of papillary glioneuronal tumor due to intra-tumoral hemorrhage in a toddler: an odd presentation of a rare pathology

BACKGROUND AND IMPORTANCE

Papillary glioneuronal tumor is a recently known entity in central nervous system tumors. These benign WHO grade I tumors are mostly seen in young adults. Pediatric PGNT is rare and there is no report of these tumors in toddlers. Headache, nausea/vomiting and seizure are most common clinical symptoms. Acute presentation with focal neurological deficits or loss of consciousness are not amongst the expected presentations. These tumors are typically cystic with enhancing mural nodule. Although case with chronic intermittent microhemorrhages are reported in the literature but overt intra-tumoral hemorrhage is an odd radiological presentation with just one reported case in the literature.

CLINICAL PRESENTATION

We present an extremely rare case of PGNT presenting with sudden onset hemiparesis and impaired consciousness due to acute intra-tumoral hemorrhage in a toddler which was surgically treated with favorable outcome.

CONCLUSION

PGNTs can also be seen in very young children even in toddlers. Also, it should be kept in mind that these tumors have potential for overt intra-tumoral hemorrhage and acute presentation with focal neurological deficits mimicking more common pathologies which should be considered to plan optimal patient management.

Papillary glioneuronal tumors: A radiopathologic correlation

OBJECTIVE

Papillary glioneuronal tumors (PGNT) are a rare and recently recognized tumor entity. The neuroimaging findings were reviewed to determine if any specific findings emerge to assist a preoperative diagnosis of PGNT.

MATERIALS AND METHODS

Seven histologically confirmed cases of PGNT were evaluated from 2004 to 2014. Clinical, neuroimaging and histological findings were reviewed and tabulated.

RESULTS

Headache and seizures were observed in 4 patients (57.1%) each. The majority (n=5, 71.4%) of lesions were periventricular and located in temporal lobe with 57.1% cases being solid cystic (n=4), and 42.9% being purely solid (n=3). Calcification and hemorrhage were noted in 3 cases (42.9%) and 5 cases (71.4%) respectively. The most frequent imaging feature was the presence of septations in the cystic component that enhanced on contrast which correlated with long pseudopapillary projections into the cyst cavity on histopathology. The solid inner component demonstrated heterogeneous enhancement. One case with tumor recurrence demonstrated hemorrhage with superficial siderosis, patchy diffusion restriction, raised choline and focal areas of raised perfusion which correlated on histopathology with increased cellularity and anaplasia.

CONCLUSION

Presence of cystic mass in periventricular location with septations and a solid inner component should raise a suspicion of PGNT on neuroimaging.

Clinicopathologic and neuroradiologic studies of papillary glioneuronal tumors

BACKGROUND

Papillary glioneuronal tumor (PGNT) is a rare, recently described distinct low-grade brain neoplasm. This study was performed to characterize the clinicopathologic and neuroradiologic features of PGNTs.

METHODS

We reviewed the medical records of 16 patients with PGNT who underwent surgery, including 11 males and five females (median age 27 years). The clinical, neuroradiologic, histopathologic, and immunohistochemical findings were documented.

RESULTS

Headache was the principal presentation. Neuroimaging showed contrast-enhancing, cystic-solid or cystic masses with a mural nodule, mostly involved the frontal or parietal lobes. Histologically, the tumors were characterized by glial fibrillary acidic protein (GFAP)-positive small cuboidal cells lining hyalinized vascular pseudopapillae and synaptophysin and/or NeuN-positive interpapillary neuronal elements. Other findings included small angiomatous areas in ten, small islands of neuropil and rosettes in seven, and microvascular proliferation and/or nuclear atypia in six. Mitoses or necrosis were absent. All lacked isocitrate dehydrogenase 1 (IDH1) R132H protein expression. Low expression of p53 was observed in three cases. Ki67 labeling index ranged from less than 1 to 3 %. All but one was totally resected. Median follow-up was 65 months, and one patient had tumor recurrence.

CONCLUSIONS

PGNTs display distinct clinicopathologic and imaging characteristics and indicate a favorable prognosis. However, recurrences sometimes occur. Immunohistochemistry facilitates the appropriate diagnosis of these tumors. Complete resection of the tumor is important for a favorable outcome.