Papillary glioneuronal tumor--a rare entity: report of four cases and brief review of literature

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 Tumour: A Case Report

Only a few cases of papillary glioneuronal tumour (PGNT) with predominantly focal symptomatology are described in the literature. We report on the clinical, radiological, and histopathological features of PGNT. The intraoperative pathology revealed no tumour in the walls of the cyst, thus surgical resection of the nodule was performed leaving the cyst wall intact. There was no recurrence of tumour at the three-year follow-up, although a long-term follow-up is necessary.

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.

Neuroradiological features of papillary glioneuronal tumor: a study of 8 cases

OBJECTIVE

The purpose of this study was to characterize the magnetic resonance imaging (MRI), and computed tomographic (CT) findings in a series of 8 patients with papillary glioneuronal tumor (PGNT).

METHODS

The routine MRI (n = 8), DWI (n = 7), and CT (n = 4) of 8 PGNTs verified by pathologic examination were reviewed. The location, internal architecture, calcification, attenuation value on CT; and signal features and degree of enhancement of the lesions on MRI were evaluated.

RESULTS

Papillary glioneuronal tumor showed relatively characteristic imaging features as well-demarcated masses with cystic degeneration, calcification, and inhomogeneous enhancement. Six of the 8 cases were located in the periventricular area. The solid part of the lesion was isointense (n = 5/8) or hypointense (n = 3/8) to gray matter on T1-weighted imaging. Diffusion-weighted imaging presented heterogeneous hypointensity and isointensity (n = 4/7) or homogeneous hypointensity (n = 3/7) in the solid part of the lesion.

CONCLUSIONS

The location adjacent to lateral ventricle, isointensity on T1-weighted imaging, and low signal on DWI may be of some specificity to PGNT.

An individual patient data meta-analysis on characteristics and outcome of patients with papillary glioneuronal tumor, rosette glioneuronal tumor with neuropil-like islands and rosette forming glioneuronal tumor of the fourth ventricle

Background and Purpose

In 2007, the WHO classification of brain tumors was extended by three new entities of glioneuronal tumors: papillary glioneuronal tumor (PGNT), rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) and glioneuronal tumor with neuropil-like islands (GNTNI). Focusing on clinical characteristics and outcome, the authors performed a comprehensive individual patient data (IPD) meta-analysis of the cases reported in literature until December 2012.

Methods

PubMed, Embase and Web of Science were searched for peer-reviewed articles reporting on PGNT, RGNT, and GNTNI using predefined keywords.

Results

95 publications reported on 182 patients (PGNT, 71; GNTNI, 26; RGNT, 85). Median age at diagnosis was 23 years (range 4–75) for PGNT, 27 years (range 6–79) for RGNT, and 40 years (range 2–65) for GNTNI. Ninety-seven percent of PGNT and 69% of GNTNI were located in the supratentorial region, 23% of GNTNI were in the spinal cord, and 80% of RGNT were localized in the posterior fossa. Complete resection was reported in 52 PGNT (73%), 36 RGNT (42%), and 7 GNTNI (27%) patients. Eight PGNT, 3 RGNT, and 12 GNTNI patients were treated with chemo- and/or radiotherapy as the primary postoperative treatment. Follow-up data were available for 132 cases. After a median follow-up time of 1.5 years (range 0.2–25) across all patients, 1.5-year progression-free survival rates were 52±12% for GNTNI, 86±5% for PGNT, and 100% for RGNT. The 1.5-year overall-survival were 95±5%, 98±2%, and 100%, respectively.

Conclusions

The clinical understanding of the three new entities of glioneuronal tumors, PGNT, RGNT and GNTNI, is currently emerging. The present meta-analysis will hopefully contribute to a delineation of their diagnostic, therapeutic, and prognostic profiles. However, the available data do not provide a solid basis to define the optimum treatment approach. Hence, a central register should be established.

Clinical, radiological, and pathological features of 16 papillary glioneuronal tumors

BACKGROUND

Papillary glioneuronal tumors (PGNTs) are a novel distinct intracranial neoplastic entity. In this study, the authors aimed to analyze the clinical, radiological, and pathological features of PGNT.

METHODS

Clinical charts and radiographs of 16 cases of PGNT surgically treated between 2006 and 2013 were retrospectively reviewed. Follow-up evaluations and a literature review were performed.

RESULTS

The study included nine males and seven females with a mean age of 23.8 years. The most common preoperative symptom was headache (68.8 %, 11 of 16 patients). Radiological results showed that the frontal lobe (25.0 %) was the most common portion of the brain involved, and 13 lesions (81.3 %) presented with cystic appearance with or without solid elements. All patients were misdiagnosed as non-PGNT tumors. Complete resection was achieved in 12 patients (75.0 %). Ki67 staining was positive in <1 % of cells present in eight lesions and varied in the other eight lesions, with a range of 1 % to 13 %. The mean follow-up duration was 56.2 months, and no recurrence was observed. Seventy-seven PGNTs (40 males, 51.9 %) have been reported, and 49 patients stained positive for Ki67/MIB-1. Of these cases, 28 (57.1 %) had positive staining rates of ≥1 %. In 51 patients for whom outcome information was available, six (11.8 %) exhibited recurrence, and the recurrence rates for complete resection and incomplete resection were 5.1 % and 33.3 %, respectively.

CONCLUSIONS

PGNTs displayed a wide spectrum of clinical and radiological phenotypes, and they were more frequently observed in the frontal lobe and in young patients without sex predilection. Fair outcomes could be achieved by complete resection. Although PGNT displayed indolent pathobiology, atypical appearances were observed. More patients and longer follow-up periods are needed to further elucidate the biological features of PGNTs.