Surgical Resection and Cellular Proliferation Index Predict Prognosis for Patients with Papillary Glioneuronal Tumor: Systematic Review and Pooled Analysis

Breaking new ground: can artificial intelligence and machine learning transform papillary glioneuronal tumor diagnosis?

Papillary glioneuronal tumors (PGNTs), classified as Grade I by the WHO in 2016, present diagnostic challenges due to their rarity and potential for malignancy. Xiaodan Du et al.'s recent study of 36 confirmed PGNT cases provides critical insights into their imaging characteristics, revealing frequent presentation with headaches, seizures, and mass effect symptoms, predominantly located in the supratentorial region near the lateral ventricles. Lesions often appeared as mixed cystic and solid masses with septations or as cystic masses with mural nodules. Given these complexities, artificial intelligence (AI) and machine learning (ML) offer promising advancements for PGNT diagnosis. Previous studies have demonstrated AI's efficacy in diagnosing various brain tumors, utilizing deep learning and advanced imaging techniques for rapid and accurate identification. Implementing AI in PGNT diagnosis involves assembling comprehensive datasets, preprocessing data, extracting relevant features, and iteratively training models for optimal performance. Despite AI's potential, medical professionals must validate AI predictions, ensuring they complement rather than replace clinical expertise. This integration of AI and ML into PGNT diagnostics could significantly enhance preoperative accuracy, ultimately improving patient outcomes through more precise and timely interventions.

Papillary glioneuronal tumor: a case report of the cerebral aqueduct and review of literature

Papillary glioneuronal tumour is an entity described as grade I neuronal-glial tumour by the World Health Organization. Headaches, seizures, vomiting, language or visual disturbances, and hemiparesis are the most common clinical findings. This tumour typically presents as cystic with enhancing mural nodule in the cerebral hemisphere. In this paper, we reported a case of a papillary glioneuronal tumour in a young adult whose magnetic resonance imaging revealed a solid tumour in the cerebral aqueduct. The tumour was totally resected surgically 13 years ago. The histological and immunohistochemical examination determined the diagnosis. No further therapy was necessary. Currently, the patient presents no neurologic signs or symptoms and there is no radiologic evidence of tumour relapse. The case of papillary glioneuronal tumour reported here displayed unusual location and radiologic features. The long duration of follow-up of this case with no tumour relapse enhances that the preferred management for this type of tumour is its total surgical resection.

Imaging manifestations of papillary glioneuronal tumors

To analyse the imaging findings of papillary glioneuronal tumors (PGNTs), in order to improve the accuracy of preoperative diagnosis of this tumor. The clinical and imaging manifestations of 36 cases of PGNT confirmed by pathology were analyzed retrospectively. A total of 17 males and 19 females, averaging 22.47 (± 11.23) years. Initial symptoms included epilepsy in ten, headache in seven, and others in 19 cases. 97.2% (35/36) of the lesions were located in the supratentorial area, and 80.5% (29/36) in the intraventricular or deep white matter adjacent to the lateral ventricles. Twenty-four of the lesions (66.7%) were mixed cystic and solid, four (11.1%) were cystic with mural nodules, four (11.1%) were cystic, and four (11.1%) were solid. Four cases of PGNT of cystic imaging showed a "T2-FLAIR mismatch" sign. 69.4% (25/36) had septations. Nine lesions (25%) were accompanied by edema, and 9 (25%) of the mixed cystic and solid lesions were accompanied by hemorrhage. Among the 18 patients who underwent computed tomography (CT) or susceptibility-weighted imaging (SWI), nine had lesions with calcification. PGNTs mostly manifest as cystic mass with mural nodules or mixed cystic and solid mass in the white matter around the supratentorial ventricle, and the cystic part of the lesion is mostly accompanied by septations. Pure cystic lesions may exhibit the sign of "T2-FLAIR mismatch". PGNT is rarely accompanied by edema but sometimes by calcification and hemorrhage. Patients often present with seizures, headaches, and mass effect symptoms.

Papillary Glioneuronal Tumor Masquerading as Malignant Brain Tumors: A Case Report

Papillary glioneuronal tumor (PGNT) is a low-grade biphasic tumor that is composed of glial fibrillary acidic protein (GFAP)-positive glial cells and synaptophysin-positive neurons. We report a case of PGNT occurring in the right occipital lobe of a 48-year-old woman who presented with acute headache and left homonymous hemianopsia, the latter of which was difficult to distinguish from malignant brain tumors because of peritumoral brain edema, intratumoral hemorrhage, and intraoperative fluorescence staining. PGNT should be included as one of the differential diagnoses in cases where the tumor shows hemorrhagic change despite decreased perfusion in arterial spin labeling MRI.

Varied histomorphology and clinical outcomes of FGFR3-TACC3 fusion gliomas

Targeted therapies for driver gene fusions in cancers have yielded substantial improvements in care. Here, the authors outline a case series of 6 patients with FGFR3-TACC3 fusion in primary brain tumors ranging from polymorphous low-grade neuroepithelial tumor of the young to papillary glioneuronal tumors and glioblastoma (GBM). Previous studies indicated the FGFR3-TACC3 fusion provides survival benefit to GBM patients. Consistent with this, 2 patients with GBM had unexpectedly good outcomes and survived for 5 and 7 years, respectively. In contrast, 2 patients with initially lower graded tumors survived only 3 years and 1 year, respectively. One patient received erdafitinib, a targeted FGFR inhibitor, for 3 months at late disease recurrence and no response was seen. There were varied histomorphological features, including many cases that lacked the characteristic FGFR3-TACC3 pathology. The findings of this cohort suggest that molecular testing is justified, even for glioma cases lacking classic histopathological signatures. Currently, FGFR3-TACC3 fusion gliomas are often classified on the basis of histopathological features. However, further research is needed to examine whether IDH1/2-wild-type tumors with FGFR3-TACC3 fusion should be classified as a subtype on the basis of this molecular fusion. Because patients with IDH1/2-wild-type GBM with FGFR3-TACC3 fusion have improved survival, routine molecular testing for this mutation in patients enrolled in clinical trials and subsequent stratification may be warranted.

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.

A Case of Suprasellar Papillary Glioneuronal Tumor Mimicking Craniopharyngioma

Papillary glioneuronal tumor (PGNT) is a low-grade biphasic neoplasm with astrocytic and neuronal differentiation. This tumor occurs most commonly in the frontal and temporal lobes, close to the ventricles, and rarely in the cerebellum, brainstem, and pineal gland. However, there has been no report of this tumor in the suprasellar region to date. In this paper, we report a case of PGNT in the suprasellar region in a 16-year-old girl. Magnetic resonance imaging (MRI) revealed a cystic tumor with calcification that progressed from the anterior skull base to the suprasellar and temporal regions. Preoperatively distinguishing this tumor from craniopharyngioma was difficult because of the patient’s age, localization of the tumor, and neuroimaging results. This case showed a backward shift of the chiasma, which is observed in only 4.7% of craniopharyngioma, as well as normal endocrine findings. Endocrinological examination and an MRI evaluation of the chiasmal shift may be useful for discrimination.

5-ALA fluorescence in a WHO grade I papillary glioneuronal tumour: a case report

5-ALA is proven to be effective in high-grade glioma operative resection. The use of 5-ALA in WHO grade I lesions is still controversial. A 49-year-old lady was diagnosed in 2004 with a left temporal lobe lesion as an incidental finding; she was followed up clinically and radiologically. In 2016, the lesion showed contrast enhancement and she was offered surgical resection but given she is asymptomatic, she refused. In 2018, the lesion showed signs of transformation with ring contrast enhancement, increased vasogenic oedema and perfusion; the patient accepted surgery at that point. She had preoperative mapping by navigated transcranial magnetic stimulation and she had operative resection with 5-ALA. The tumour was bright fluorescent under Blue 400 filter—Zeiss Pentero 900©(Carl Zeiss Meditec)—and both bright fluorescence and pale fluorescence were resected. Postoperative MRI showed complete resection and histopathology revealed WHO grade I papillary glioneuronal tumour, negative for BRAF V600 mutation. WHO grade I papillary glioneuronal tumour may present as 5-ALA fluorescent lesions. From a clinical perspective, 5-ALA can be used to achieve complete resections in these lesions which, in most cases, can be curative.

Papillary glioneuronal tumor (PGNT) exhibits a characteristic methylation profile and fusions involving PRKCA

Papillary glioneuronal tumor (PGNT) is a WHO-defined brain tumor entity that poses a major diagnostic challenge. Recently, SLC44A1-PRKCA fusions have been described in PGNT. We subjected 28 brain tumors from different institutions histologically diagnosed as PGNT to molecular and morphological analysis. Array-based methylation analysis revealed that 17/28 tumors exhibited methylation profiles typical for other tumor entities, mostly dysembryoplastic neuroepithelial tumor and hemispheric pilocytic astrocytoma. Conversely, 11/28 tumors exhibited a unique profile, thus constituting a distinct methylation class PGNT. By screening the extended Heidelberg cohort containing over 25,000 CNS tumors, we identified three additional tumors belonging to this methylation cluster but originally histologically diagnosed otherwise. RNA sequencing for the detection of SLC44A1-PRKCA fusions could be performed on 19 of the tumors, 10 of them belonging to the methylation class PGNT. In two additional cases, SLC44A1-PRKCA fusions were confirmed by FISH. We detected fusions involving PRKCA in all cases of this methylation class with material available for analyses: the canonical SLC44A1-PRKCA fusion was observed in 11/12 tumors, while the remaining case exhibited a NOTCH1-PRKCA fusion. Neither of the fusions was found in the tumors belonging to other methylation classes. Our results point towards a high misclassification rate of the morphological diagnosis PGNT and clearly demonstrate the necessity of molecular analyses. PRKCA fusions are highly diagnostic for PGNT, and detection by RNA sequencing enables the identification of rare fusion partners. Methylation analysis recognizes a unique methylation class PGNT irrespective of the nature of the PRKCA fusion.