Glioneuronal tumor with unique imaging and histologic features

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.

Spinal cord glioneuronal tumor with rosetted neuropil-like islands in pediatric age group

Glioneuronal neoplasms are rare tumors. Recently, an unusual glioneuronal tumor histologically showing neuropil-like islands has been described. Here, we present such a tumor originating from spinal cord of a 14-year-old girl, who has scoliosis and urinary incontinence. Microscopically, the glial component was chiefly fibrillary astrocytic, punctuated by neuropil-like islands. Immunohistochemically, glial tissue was GFAP positive, and neuropil-like areas and big neurons were synaptophysin reactive. For astrocytic component Ki-67 proliferation index was 1% and p53 was immunonegative. This case is unique in that in the literature it is the second reported case in pediatric age group that is located at spinal cord.

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.

Spinal cord glioneuronal tumor with neuropil-like islands with 1p/19q deletion in an adult with low-grade cerebral oligodendroglioma

Glioneuronal tumor with neuropil-like islands (GTNI) is considered a rare variant of astrocytoma, characterized by discrete aggregates of cells expressing neuronal markers that punctuate a GFAP-positive glial background. Of the 24 published GTNI cases, only two occurred in adult spinal cords; none occurred concurrent with another CNS tumor; and none of those tested exhibited the 1p/19q deletion typical of oligodendroglioma. A 48-year-old man without significant past medical history was diagnosed with a WHO grade II oligodendroglioma by stereotactic biopsy of a lesion discovered after the patient suffered a generalized tonic-clonic seizure. By FISH analysis, this tumor exhibited the 1p/19q deletion present in up to 80% of oligodendrogliomas. The patient received 14 monthly cycles of temozolomide, and his cerebral tumor had a minor response. When the patient subsequently reported progressive paresthesias of his lower extremities, an MRI revealed an enhancing, cystic tumor of the thoracic spinal cord that was diagnosed as GTNI by histological analysis. By FISH analysis, this lesion exhibited the same 1p/19q deletion present in the concurrent cerebral oligodendroglioma. This case of a spinal cord GTNI with 1p/19q deletions constitutes the third report of a spinal cord GTNI in an adult patient; the first report of a GTNI in an individual with a separate CNS neoplasm; and the first report of a GTNI with 1p/19q deletions. This case establishes a potential genetic kinship between GTNI and oligodendroglioma that warrants further investigation.

Glioneuronal tumor with neuropil-like islands of the spinal cord with diffuse leptomeningeal neuraxis dissemination

A 54-year-old Caucasian female presented with a 1 year history of intermittent numbness of the left leg progressing to bilateral, lower extremity sensory loss that advanced to include impaired vibration and proprioception. The subsequent thoracic spine magnetic resonance imaging (MRI) scan revealed a heterogeneous, avidly enhancing, centrally situated spinal cord mass involving T7 through T10 in association with thick linear enhancement of the anterior and posterior cord surfaces extending both superiorly and inferiorly. Both the cervical and lumbar spine MRI demonstrated diffuse leptomeningeal disease as well. A brain MRI revealed focal leptomeningeal enhancement in the left and right sylvian fissures, the suprasellar cistern, and the posterior fossa; a pattern consistent with metastatic disease. The patient underwent a T6-T10 laminectomy for tumor biopsy and debulking. Histology revealed a WHO grade III glioneuronal tumor with rosetted neuropil-like islands. Synaptophysin and neurofilament (NF) positive staining was noted within the neural appearing component, whereas, glial fibrillary acidic protein (GFAP) immunopositivity was evident in the fibrillary astrocytoma component of the tumor. The Ki-67 labeling index was 7%. This tumor pattern, now included in the 2007 World Health Organization (WHO) classification of central nervous system tumours as a pattern variation of anaplastic astrocytoma (Kleihues et al. In: Louis et al. (eds) WHO classification of tumours of the central nervous system, 2007), was first described in a four-case series by Teo et al. in 1999. The majority of subsequently reported cases described them as primary tumors of the cerebrum. Herein, we report a unique example of a spinal glioneuronal tumor with neuropil-like islands with associated leptomeningeal dissemination involving the entire craniospinal axis.

Cytogenetic study of glioneuronal tumor with neuropil-like islands: a case report

Glioneuronal tumor with neuropil-like islands (GTNI) is a recently recognized glioneuronal neoplasm but it was classified as an astrocytic tumor by the World Health Organization (WHO) in 2007. We performed a cytogenetic study in a case of GTNI arising in a 55-year-old man and analyzed its genetic alteration. It presented as a heterogeneously enhancing, multi-lobulating solid mass on MRI. Histopathologically, the tumor showed the biphasic feature of the predominating micronodular neuropil-like islands and the diffusely infiltrating glial component. In addition, the prominent blood vessels with perivascular hyalinization were observed. On cytogenetic study, loss of 4q, 5q, 11p and gain of 6p, 7, 8, 11q, 12p, 15q were found. The remaining tumor after subtotal resection progressed 7 months later, despite combined chemo- and radiotherapy. From the results, it seems that GTNI does not share pathologic or genetic features with conventional astrocytoma, suggesting a unique entity with aggressive behavior.

Glioneuronal Tumor With Neuropil-like Islands (GTNI): A Report of 8 Cases With Chromosome 1p/19q Deletion Analysis

Glioneuronal tumor with neuropil-like islands (GTNI) is a rare neoplasm harboring circumscribed loci of neuronal differentiation and diffusely infiltrating astroglial and oligodendrocytelike components. We report 8 previously unpublished examples of GTNI, specifically studied for chromosome 1p and 19q allelic losses. All tumors showed characteristic histologic features and immunoprofile. One primary tumor displayed frankly malignant histology with frequent mitoses, microvascular proliferation, and necrosis. This tumor progressed within months of the initial resection. Three other tumors (2 low-grade and 1 showing only focal microvascular proliferation) recurred at 2 years, 3 years, and 1 year, respectively. All cases were evaluated for 1p/19q allelic losses by standard polymerase chain reaction-based loss of heterozygosity assays. No evidence of 1p/19q losses was found in 7 of 8 tumors. One tumor demonstrated small interstitial deletions at 1p36 (at D1S1612 and D1S513, but not at D1S548 or D1S1592) and a small interstitial deletion at 19q13 (at D19S219 and D19S412, but not at PLA2G4C). The lack of large, whole-arm 1p/19q losses (such as those found in oligodendroglial tumors), aberrant p53 expression, and the predominance of astroglial components may indicate a biologic relationship of the GTNI to diffuse astrocytoma. Although GTNI shares some morphologic features with recently reported cases of oligodendroglioma with neurocytic differentiation, the 2 tumors appear different at the molecular genetic level.

Unusual malignant glioneuronal tumors of the cerebrum of adults: a clinicopathologic study of three cases

Malignant glioneuronal tumors of the brain are rare and poorly characterized. Herein, we report the clinicopathologic features of three examples with unusual morphologies including both glial and neuronal differentiation. Hematoxylin and eosin-stained slides were reviewed in all cases. Immunohistochemical stains were performed on formalin-fixed, paraffin-embedded sections. Transmission electron microscopy (EM) was performed on both formalin-fixed (n=1) and paraffin embedded tissue (n=2). The immunogold technique for localization of GFAP was also performed. Two patients were male and one was female, age 66, 84, and 34 years, respectively. Radiologic studies demonstrated hyperdensity on CT (n=3), multicentricity (n=2), and a cortical based solid component with a cystic extension into underlying white matter (n=2). At surgery, all three tumors were superficial and relatively circumscribed. Histologically, they were composed of large epithelioid cells (n=3), spindle cells (n=1), and poorly differentiated smaller cells with high nuclear/cytoplasmic ratios (n=1). Brisk mitotic activity and coagulative non-palisading necrosis were present in all cases. The tumors were immunopositive for GFAP (n=3), S-100 (n=3), synaptophysin (n=3), chromogranin (n=3), Neu-N (n=2), and neurofilament protein (n=2). Stains for EMA were negative. EM demonstrated convincing neurosecretory granules in one case, some in filament-containing cells immunogold labeled for GFAP. Two patients expired 3-5 weeks after surgery. True malignant neoplasms with glial and neuronal differentiation do occur in the central nervous system of adults and may pursue a highly aggressive course. The use of minimal diagnostic criteria, e.g., immunoreactivity for a single antigen like neurofilament protein, may not be sufficient and should be discouraged.