Diffuse leptomeningeal glioneuronal tumor (DLGNT) mimicking Whipple's disease: a case report and literature review

Diffuse leptomeningeal glioneuronal tumor in an 8-year-old girl: case report and review of the literature

Diffuse leptomeningeal glioneuronal tumors (DLGNTs) are rare central nervous system tumors of childhood that were recently described as a new entity. DLGNTs usually manifest with symptoms related to increased intracranial pressure or spinal cord compression. The classic radiological feature is a widespread leptomeningeal enhancement that may involve the entire neuroaxis. Microscopic examination demonstrates oligodendroglial-like cells that are positive for OLIG2, MAP2, and S100 and negative for IDH-1. Anaplastic features occur in some cases. Molecularly, DLGNTs are characterized by chromosome arm 1p deletion and alteration of a mitogen-activated protein kinase (MAPK) pathway gene, most commonly BRAF-KIAA1549 fusion. There is no established grading system for these tumors, which may have an indolent or aggressive behavior. Treatment usually involves chemotherapy and radiation therapy.

Pediatric spinal pilocytic astrocytomas form a distinct epigenetic subclass from pilocytic astrocytomas of other locations and diffuse leptomeningeal glioneuronal tumours

Pediatric spinal low-grade glioma (LGG) and glioneuronal tumours are rare, accounting for less 2.8-5.2% of pediatric LGG. New tumour types frequently found in spinal location such as diffuse leptomeningeal glioneuronal tumours (DLGNT) have been added to the World Health Organization (WHO) classification of tumours of the central nervous system since 2016, but their distinction from others gliomas and particularly from pilocytic astrocytoma (PA) are poorly defined. Most large studies on this subject were published before the era of the molecular diagnosis and did not address the differential diagnosis between PAs and DLGNTs in this peculiar location. Our study retrospectively examined a cohort of 28 children with LGGs and glioneuronal intramedullary tumours using detailed radiological, clinico-pathological and molecular analysis. 25% of spinal PAs were reclassified as DLGNTs. PA and DLGNT are nearly indistinguishable in histopathology or neuroradiology. 83% of spinal DLGNTs presented first without leptomeningeal contrast enhancement. Unsupervised t-distributed stochastic neighbor embedding (t-SNE) analysis of DNA methylation profiles showed that spinal PAs formed a unique methylation cluster distinct from reference midline and posterior fossa PAs, whereas spinal DLGNTs clustered with reference DLGNT cohort. FGFR1 alterations were found in 36% of spinal tumours and were restricted to PAs. Spinal PAs affected significantly younger patients (median age 2 years old) than DLGNTs (median age 8.2 years old). Progression-free survival was similar among the two groups. In this location, histopathology and radiology are of limited interest, but molecular data (methyloma, 1p and FGFR1 status) represent important tools differentiating these two mitogen-activated protein kinase (MAPK) altered tumour types, PA and DLGNT. Thus, these molecular alterations should systematically be explored in this type of tumour in a spinal location.

Clinical progression, pathological characteristics, and radiological findings in children with diffuse leptomeningeal glioneuronal tumors: A systematic review

Background

Diffuse leptomeningeal glioneuronal tumors are rare leptomeningeal neoplasms composed of oligodendrocyte-like cells characterized by neuronal differentiation and a lack of isocitrate dehydrogenase gene mutation.

Purpose

We aimed to analyze the clinical progression, pathological characteristics, and radiological findings of diffuse leptomeningeal glioneuronal tumors in children, as well as the relevance of clinico-radiological data.

Data Sources

We searched MEDLINE, PubMed, and Web of Science to identify case reports, original articles, and review articles discussing diffuse leptomeningeal glioneuronal tumors published between 2000 and 2021.

Study Selection

The analysis included 145 pediatric patients from 43 previous studies.

Data Analysis

Data regarding patient pathology, MRI manifestations, clinical symptoms, and progression were collected. The relationship between imaging classification and pathological findings was using chi-square tests. Overall survival was analyzed using Kaplan–Meier curves.

Data Synthesis

Parenchymal tumors were mainly located in the intramedullary areas of the cervical and thoracic spine, and patients which such tumors were prone to 1p-deletion (χ2 = 4.77, p=0.03) and KIAA1549-BRAF fusion (χ2 = 12.17, p<0.001). The median survival time was 173 months, and the survival curve fell significantly before 72 months. Parenchymal tumor location was associated with overall survival (p=0.03), patients with KIAA 1549-BRAF (+) and treated with chemotherapy exhibited a better clinical course (p<0.001).

Limitations

The analysis included case reports rather than consecutively treated patients due to the rarity of diffuse leptomeningeal glioneuronal tumors, which may have introduced a bias.

Conclusions

Early integration of clinical, pathological, and radiological findings is necessary for appropriate management of this tumor, as this may enable early treatment and improve prognosis.

Prognostic factors in diffuse leptomeningeal glioneuronal tumor (DLGNT): a systematic review

BACKGROUND

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare tumor, first described by the WHO Classification of Central Nervous System Tumors in 2016. The clinical course is variable. Most tumors have low-grade histological findings although some may have more aggressive features. The goal of this systematic review was to identify prognostic factors for poor overall survival (OS).

MATERIAL AND METHODS

We performed a systematic review using three databases (PubMed, Google Scholar, and Embase) and the following search terms: diffuse leptomeningeal glioneuronal tumor, DLGNT, DLMGNT. Statistical analysis was performed using Statistica 13.3.

RESULTS

We included 34 reports in our review comprising 63 patients, published from 2016 to 2022. The median OS was 19 months (range: 12-51 months). Using multivariable Cox survival analysis, we showed that Ki-67 ≥ 7%, age > 9 years, symptoms of elevated intracranial pressure (ICP) at admission, and the presence of contrast-enhancing intraparenchymal tumor are associated with poor OS. Receiver operating characteristic (ROC) analysis identified Ki-67 ≥ 7% as a significant predictor of poor OS.

CONCLUSIONS

Signs or symptoms of increased ICP with imaging findings of diffuse leptomeningeal enhancement should raise suspicion for DLGNT. In our systematic review, Ki-67 ≥ 7% was the most important prognostic factor for OS in DLGNT. The presence of intraparenchymal tumor with contrast enhancement was thought to represent disease progression and, together with patient age, was associated with poor OS.

Atypical and aggressive diffuse leptomeningeal glioneuronal tumor in a young adult: A case report and review of the literature

Background

DLGNT is a rare tumor, commonly diagnosed in pediatric age; in most cases, the pathology presents a slow and indolent evolution. We present a case report of a young adult affected by DLGNT characterized by aggressive and atypical behavior.

Case Description

A 21-year-old male presented with mild paraparesis and hypoesthesia with a D2 level. MRI scan of the brain and spine showed a dorsal intramedullary lesion; a diffuse craniospinal leptomeningeal thickening was also present. After a week, the neurological status deteriorated rapidly with paraparesis worsening and onset of acute hydrocephalus. The patient underwent external ventricular drain positioning; a C7-D4 laminectomy was subsequently performed with partial tumor resection. Histological examination revealed a DLGNT with aggressive aspects (Ki67 30%). Postoperatively, the patient showed an immediate mild worsening of the lower limbs deficit. After a few days, severe further neurological deterioration occurred with progressive motor deficit to the upper limbs and ultimately respiratory failure. Mechanical ventilation was necessary and the patient was transferred to the ICU; during the following weeks, he developed tetraplegia and underwent ventriculoperitoneal shunt positioning. By the time, the histological diagnosis was available, the clinical status would not allow radiotherapy or chemotherapy. The patient deceased approximately 90 days after hospitalization due to respiratory complications.

Conclusion

DLGNT is a rare tumor; diagnosis requires a high index of suspicion and confirmation with biopsy. Although most cases have an indolent course, some patients may have aggressive forms. High proliferation index, hydrocephalus occurrence, and massive craniospinal leptomeningeal spread appear to be associated with worse prognosis.

Diffuse leptomeningeal glioneuronal tumor without KIAA1549-BRAF fusion and 1p detection: a case report and review of literature

BACKGROUND

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare mixed neuronal-glial tumor of central nervous system. Chromosome microarray usually identifies co-deletion of the short arm of chromosome 1 and the long arm of chromosome 19 as well as fusion of the KIAA1549 and BRAF genes.

METHODS

We describe a case of a 3-year-old boy with typical imaging and histopathological features, but without KIAA1549-BRAF fusion and 1p deletion. Additionally, a literature review is performed summarizing the clinical features, management, and prognosis of this rare entity.

RESULTS

A 3-year-old boy presented with chronic headache and vomiting. On initial MRI scanning, diffuse thickening with enhancement of the cerebral and spinal leptomeninges could be detected after contrast injection. Multiple cystic lesions were found located on infratentorial leptomeninges, with progressive thickening of leptomeninges and increasing cysts on follow-up MRI after 9 months. Meningeal biopsy was carried out, showing that most of tumor cells were composed of oligodendroglioma-like cells. The tumor cells were immunopositive for GFAP, Olig-2, and synaptophysin but negative for IDH-1 and H3k27M. Molecular genetic testing did not detect KIAA1549-BRAF fusion, 1p deletion, or 1p/19q co-deletion. The patient was finally diagnosed as DLGNT after multidisciplinary team consultation.

CONCLUSIONS

Given that the clinical and pathological mechanism of DLGNTs remains unclear, our case gives supplement about the diversity of molecular genetic characteristics. Combination of clinical, neuroradiological, and histopathological data is particularly important for the diagnosis of DLGNTs, till now.

Diffuse Leptomeningeal Glioneuronal Tumour with 9-Year Follow-Up: Case Report and Review of the Literature

In 2016, the World Health Organisation Classification (WHO) of Tumours was updated with diffuse leptomeningeal glioneuronal tumour (DLGNT) as a provisional unit of mixed neuronal and glial tumours. Here, we report a DLGNT that has been re-diagnosed with the updated WHO classification, with clinical features, imaging, and histopathological findings and a 9-year follow-up. A 16-year-old girl presented with headache, vomiting, and vertigo. Magnetic resonance imaging (MRI) demonstrated a hyperintense mass with heterogenous enhancement in the right cerebellopontine angle and internal auditory canal. No leptomeningeal involvement was seen. The histological examination revealed neoplastic tissue of moderate cellularity formed mostly by oligodendrocyte-like cells. Follow-up MRI scans demonstrated cystic lesions in the subarachnoid spaces in the brain with vivid leptomeningeal enhancement. Later spread of the tumour was found in the spinal canal. On demand biopsy samples were re-examined, and pathological diagnosis was identified as DLGNT. In contrast to most reported DLGNTs, the tumour described in this manuscript did not present with diffuse leptomeningeal spread, but later presented with leptomeningeal involvement in the brain and spinal cord. Our case expands the spectrum of radiological features, provides a long-term clinical and radiological follow-up, and highlights the major role of molecular genetic testing in unusual cases.

Diffuse leptomeningeal glioneuronal tumour: where to biopsy? Case report and literature review

PURPOSE

Diffuse leptomeningeal glioneuronal tumour (DLGT) is an infrequent entity. Diagnosis is made with biopsy but with so few cases described management, prognosis remains undefined. There are not currently any articles regarding most effective place to biopsy.

METHODS

Current literature review and introduction of the case of a 3-year-old male presenting at the emergency room with irritability, vomiting and nuchal rigidity. A head CT was made showing tetraventricular enlargement and a posterior fossa cyst.

RESULTS

Patient underwent urgent ventriculoperitoneal shunting surgery with complete symptomp resolution. Brain MRI showed diffuse leptomeningeal enhancing, predominantly in basal cisterns, and multiple cystic-solid lesions along the neural axis. After ruling other conditions, a biopsy among intraoperative samples, was obtained of a PET positive gadolinium spinal enhancing lesion at D8 level, with the final diagnosis of DLGT.

CONCLUSION

DLGT can present as acute hydrocephalus. Biopsy stablishes the diagnosis but the place to take the sample can be difficult to select. Our experience suggests that PET-CT and intraoperative biopsy analysis can improve the effectivity of a representative sample.

Spinal Cord Diffuse Leptomeningeal Glioneuronal Tumor Presenting without Leptomeningeal Dissemination

BACKGROUND AND IMPORTANCE

Diffuse leptomeningeal glioneuronal tumor (DLGNT) represents a provisional entity in the 2016 World Health Organization classification of tumors; it is characterized by a widespread leptomeningeal growth and oligodendroglial-like cytology. To this day, 4 pediatric patients have been reported to present with an isolated spinal cord tumor in the absence of leptomeningeal dissemination. Gross total resection (GTR) was achieved in only 1 patient. We present the clinical and technical nuances of this unique type of tumor, as well as the second reported case of GTR in a patient with DLGNT.

CLINICAL PRESENTATION

A 4-year-old boy presented to the emergency department after an episode of flaccid paralysis of bilateral lower extremities. MRI showed an intramedullary spinal cord tumor centered at T8. The patient was taken to the operative room, where a laminectomy and tumor resection were performed; cystic and solid tumor components were identified. Pathology report was consistent with DLGNT. After achieving GTR, patient is free of recurrence after a 15-month follow-up.

CONCLUSION

No standard treatment for DLGNT has been identified. Current literature report surgery and chemotherapy with variable success rates. DLGNT presenting as an isolated intramedullary tumor is an uncommon condition which progression appears to be halted when treated promptly. Identifying solid and cystic components of this tumor is crucial for achieving GTR.

Diffuse Leptomeningeal Glioneuronal Tumor in a 4.5-year-old Girl: A Case Report and Review of the Literature

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is an entity introduced in 2016 World Health Organization classification of tumors of the central nervous system. The tumor occurs very rarely. Due to the lack of specific clinical and radiological features, biopsy is necessary to be performed and histological and immunohistochemical testing is essential to reach the diagnosis. A 4.5-year-old girl presented with a history of headache, vomiting, and right eye convergent squint. Imaging revealed multiple enhancing lesions located supra- and infratentorially and intramedullary. Histopathological examination demonstrated diffused growth of neoplastic cells. Molecular testing revealed KIAA1549-BRAF fusion and the diagnosis of DLGNT was stated.

Diffuse Leptomeningeal Glioneuronal Tumor of Childhood

Diffuse leptomeningeal glioneuronal tumor is a newly defined entity under the neuronal and mixed neuronal-glial tumors category in the 2016 World Health Organization classification of brain tumors. In this series, we report clinical, radiologic, and histologic findings in 7 cases of diffuse leptomeningeal glioneuronal tumor. Our cases and literature review indicate that the most characteristic imaging finding is diffuse intracranial and intraspinal nodular leptomeningeal thickening and enhancement. This is often associated with small cyst-like, nonenhancing lesions. It should be noted that tumors sometimes bear nontypical features, for example, presenting as a solitary spinal cord mass without leptomeningeal involvement or with a dominant intracranial mass. In children with characteristic imaging findings and without clinical features of infection, the radiologist has an opportunity to promptly raise the possibility of diffuse leptomeningeal glioneuronal tumor, and thereby, affect streamlined diagnostic evaluation.

Diffuse leptomeningeal glioneuronal tumor in a Chinese adult: a novel case report and review of literature

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare glioma tumor classified by the World Health Organization as a central nervous system tumor in 2016. DLGNT is most common in children and adolescents but is rare in adults. A 25-year-old male patient was admitted due to recurrent seizures. Head magnetic resonance imaging revealed lesions in the right temporal lobe, which were considered to be intracranial tumors with variable properties. The patient was admitted for surgical treatment. After admission, it was confirmed that seizures were associated with right temporal lobe lesions. Right temporal epileptogenic focus resection was performed by craniotomy. Immunohistochemistry revealed that tumor cells were reactive for oligodendrocyte transcription factor 2, synaptophysin, S100 proteins, and α-thalassemia mental retardation X-linked; and partially reactive for neuronal nuclei, glial fibrillary acidic protein, and nestin. The vascular wall was reactive for vimentin, CD34, CD31, and smooth muscle actin. Ki-67 was 4%. Molecular detection demonstrated 1p36 deletion, O⁶-methylguanine-DNA-methyltransferase methylation, and positive v-raf murine sarcoma viral oncogene homolog B mutation. DLGNT. The patient recovered well after surgery and received 54 Gy/27f radiotherapy without neurological dysfunction and seizures. In this study, onset age, tumor site, tumor increment coefficient, molecular detection, treatment methods, and prognosis of 54 patients were summarized from 19 studies. DLGNT patients are characterized by more singular tumor site, smaller volume, lower increment coefficient, and longer stable disease period. Patients with DLGNT may also have a longer stable condition in cases of molecular detection of 1p/19q deletion, or BRAF fusion.

Diffuse leptomeningeal glioneuronal tumour (DLGNT) with hydrocephalus as an initial symptom: a case-based update

PURPOSE

Diffuse leptomeningeal glioneuronal tumour (DLGNT) is a rare disease classified in 2016. There are different views of the clinical, pathologic and neuroradiologic characteristics of DLGNT due to the minor studies on this disease.

METHODS

We describe a case of a 12-year-old boy who initially presented intermittent headache, vomiting and communicating hydrocephalus. A literature review is also presented summarizing the clinical characteristics and treatments of DLGNT.

RESULTS

In our case, a ventriculoperitoneal shunt was applied to reduce intracranial pressure caused by communicating hydrocephalus. T1-weighted contrast-enhanced magnetic resonance imaging (MRI) showed linear enhancement, and microscopy showed tumour-like spindle cells. The diagnosis of DLGNT was confirmed, and temozolomide was administered. The clinical characteristics were similar in the reported cases, while the treatments showed differences.

CONCLUSION

Ventriculoperitoneal shunts are effective for patients with hydrocephalus-related intracranial hypertension. Chemotherapy including temozolomide has shown varying outcomes, and further studies are expected.

Unusual radiological and histological presentation of a diffuse leptomeningeal glioneuronal tumor (DLGNT) in a 13-year-old girl

Diffuse leptomeningeal glioneuronal tumors (DLGNTs) are newly recognized as an entity in the 2016 revision of the WHO Classification of tumors of the central nervous system. They typically present as diffuse leptomeningeal infiltrates along the neuraxis with focal and superficial involvement of the parenchyma. Here, we report a DLGNT with unusual radiological and histological features. A 13-year-old girl presented with scoliosis and back pain. Magnetic resonance imaging demonstrated a syrinx from C2 to T11 and an intramedullary mass from T6 to T9-10. No leptomeningeal involvement was recognized. Histological examination of the gross total resection specimen revealed a low-grade neuroepithelial neoplasm predominantly infiltrating the spinal cord and only focally involving the leptomeninges. Chromosome microarray identified co-deletion of the short arm of chromosome 1 and the long arm of chromosome 19 as well as fusion of the KIAA1549 and BRAF genes. Next-generation sequencing demonstrated wild-type alleles at the mutational hotspots of IDH1 (R132) and IDH2 (R140 and R172). In contrast to most reported DLGNTs, the tumor described in this manuscript was characterized by a predominant parenchymal component and only minor leptomeningeal involvement both radiographically and histologically. Our case, therefore, expands the spectrum of radiological and histopathological features of this new entity. It also highlights the critical role of molecular genetic testing in establishing the diagnosis of DLGNT in unusual cases.

A germline variant of TP53 in paediatric diffuse leptomeningeal glioneuronal tumour

PURPOSE

Diffuse leptomeningeal glioneuronal tumour (DLGNT) is an extremely rare tumour involving the neuroaxis. At present, its exact pathogenesis and associated factors remain incompletely characterised. Recent molecular investigations in a small cohort have offered some insights into this disease. However, the role of germline findings has not yet been fully explored in affected patients. The authors present a case of DLGNT, focusing on the clinical and molecular features with reference to current disease knowledge.

METHODS

A 4-year-old male presented with raised intracranial pressure symptoms secondary to extensive leptomeningeal disease of the brain and spine. Preliminary impression was that of an inflammatory lesion.

RESULTS

A lumbar biopsy of the lesion confirmed DLGNT on routine diagnostic examination. Further molecular analysis of his tumour and blood demonstrated a previously unreported TP53 exon 5 (c.147V > I) germline variant. Based on the latest DLGNT molecular subtyping classification, his tumour falls into the group with better clinical outcome. However, his germline findings may add an extra layer of uncertainty to his overall prognosis.

CONCLUSION

Given that much remains unknown in many rare paediatric tumours at this stage, isolated findings found in an individual may be of significance. Supplementary genetic information, together with tumour molecular analysis, add to our current understanding of this uncommon disease. This case highlights the benefit of combined clinical and molecular efforts, including germline testing, especially for children affected by such challenging neoplasms.

Paediatric diffuse leptomeningeal tumor with glial and neuronal differentiation harbouring chromosome 1p/19q co-deletion and H3.3 K27M mutation: unusual molecular profile and its therapeutic implications

Diffuse leptomeningeal glioneuronal tumor (DL-GNT) is a newly introduced tumor entity of uncertain prognosis characterised by a primary diffuse leptomeningeal growth pattern, oligodendroglial-like morphology and dual glial/neuronal differentiation. Predominantly occurring in children, these tumors present as chronic meningitis and mimic infectious/inflammatory diseases. They are surgically challenging tumors with a high incidence of delayed morbidity and mortality despite low-grade histology. Their molecular genetic profile is not fully elucidated and few reports have identified chromosome 1p and 19q deletions, and BRAF alterations. We present a rare instance of a DL-GNT in a 13-year-old female who presented with slowly progressive and sequential neurological deficits over a 12-month duration. Imaging showed leptomeningeal thickening and spinal lesions. Biopsy from the spinal mass showed histomorphological features characteristic of DL-GNT. Further molecular analysis revealed 1p and 19q co-deletion and H3K27M mutation, while no mutation were identified in IDH, TERT, or BRAF genes. Patient died 4 months after diagnosis. Only one previous case of DL-GNT has been reported to harbour H3K27M mutation. Although H3K27M mutations have been described in rare examples of low-grade glial and glioneuronal tumors, whether DL-GNTs with H3K27M represent a rare growth pattern of the aggressive H3K27M-mutant diffuse midline gliomas needs further clarification.