Primary leptomeningeal oligodendrogliomatosis

Understanding diffuse leptomeningeal glioneuronal tumors

INTODUCTION

Diffuse leptomeningeal glioneuronal tumors (DLGNTs) pose a rare and challenging entity within pediatric central nervous system neoplasms. Despite their rarity, DLGNTs exhibit complex clinical presentations and unique molecular characteristics, necessitating a deeper understanding of their diagnostic and therapeutic nuances.

METHODS

This review synthesizes contemporary literature on DLGNT, encompassing epidemiology, clinical manifestations, pathological features, treatment strategies, prognostic markers, and future research directions. To compile the existing body of knowledge on DLGNT, a comprehensive search of relevant databases was conducted.

RESULTS

DLGNT primarily affects pediatric populations but can manifest across all age groups. Its diagnosis is confounded by nonspecific clinical presentations and overlapping radiological features with other CNS neoplasms. Magnetic resonance imaging (MRI) serves as a cornerstone for DLGNT diagnosis, revealing characteristic leptomeningeal enhancement and intraparenchymal involvement. Histologically, DLGNT presents with low to moderate cellularity and exhibits molecular alterations in the MAPK/ERK signalling pathway. Optimal management of DLGNT necessitates a multidisciplinary approach encompassing surgical resection, chemotherapy, radiotherapy, and emerging targeted therapies directed against specific genetic alterations. Prognostication remains challenging, with factors such as age at diagnosis, histological subtypes, and genetic alterations influencing disease progression and treatment response. Long-term survival data are limited, underscoring the need for collaborative research efforts.

CONCLUSION

Advancements in molecular profiling, targeted therapies, and international collaborations hold promise for improving DLGNT outcomes. Harnessing the collective expertise of clinicians, researchers, and patient advocates, can advance the field of DLGNT research and optimize patient care paradigms.

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.

[Primary leptomeningeal gliomatosis treated with temozolomide: a case report]

A 35-year-old man was admitted to our department for loss of consciousness. CT and MRI revealed diffuse enhancement of the subarachnoid space surrounding the brainstem and the cerebellar sulci, without any parenchymal lesions in the brain or the spinal cord. Furthermore, gadolinium-enhanced MRI revealed a nodular lesion with heterogeneous enhancement in the right prepontine cistern, at the site from which a biopsy was obtained via right lateral suboccipital craniotomy on the day following admission. Histopathological examination of the resected specimen revealed glioblastoma multiforme. Based on the radiological and histopathological findings, the patient was diagnosed with primary leptomeningeal gliomatosis (PLG). The patient received temozolomide chemotherapy with concurrent radiotherapy and showed radiological remission, 12 months after diagnosis. However, he developed local recurrence 6 months later and died 23 months after diagnosis. Autopsy findings showed tumor cell infiltration of the leptomeninges, as well as the brain and spinal parenchyma. PLG should be considered in the differential diagnosis in patients with diffuse leptomeningeal enhancement even without parenchymal lesions on radiological imaging. A surgical biopsy is recommended for prompt and accurate diagnosis in such cases.

Cranial and Spinal Oligodendrogliomatosis: A Case Report and Review of the Literature

Secondary leptomeningeal gliomatosis is a condition known as a result of invasion of the subarachnoid space or the ventricular system of primary intraparenchymal glioma. In this article, we present a 7-year-old boy presented with neck and back deformity and deterioration of gait. Cranial and spinal magnetic resonance imaging revealed lesions in the supratentorial and infratentorial areas, in the brainstem downward the spinal cord. Disseminated oligodendrogliomatosis is extremely rare and our case we present is the 24^th in the literature.

Diffuse meningeal oligodendrogliomatosis characterized by spinal intra-parenchymal nodules on magnetic resonance imaging in a dog

Meningeal oligodendrogliomatosis is a relatively rare neoplasm in dogs. Ante-mortem diagnosis is difficult due to nonspecific neurologic signs overlapping other conditions. The only reported consistent feature is a high level of protein in the cerebrospinal fluid. Veterinary literature offers only 1 case report with magnetic resonance imaging (MRI) of canine spinal meningeal oligodendrogliomatosis in a single dog. In contrast to the predominant diffuse meningeal enhancement shown in that report, we present the case of a young female cane corso dog with marked nodular invasion of the spinal cord on MRI, confirmed by histopathology to be consistent with diffuse meningeal oligodendrogliomatosis. Key clinical message: Meningeal oligodendrogliomatosis should be a differential diagnosis when marked nodular invasion of the spinal cord is seen on MRI, both with and without meningeal enhancement.

Primary diffuse leptomeningeal oligodendrogliomatosis with an isolated 1p deletion

We report a case of primary diffuse leptomeningeal oligodendrogliomatosis with an isolated 1p deletion confirmed by fluorescent in situ hybridization (FISH) analysis in 52 year-old man. The MRI scan in a patient presenting with progressive headache, nausea and diplopia revealed diffuse leptomeningeal thickening and enhancement without definitive evidence of an intraparenchymal lesion. Biopsy of thickened, enhancing meninges within the left sylvian fissure revealed subarachnoid proliferation of oligodendroglial cells with varying degrees of de-differentiation and sparing of the underlying cortex. An isolated 1p deletion was confirmed by FISH analysis. This is the first reported adult case of a 1p deletion in primary diffuse leptomeningeal oligodendrogliomatosis.

Parenchymal Infiltration in Primary Diffuse Leptomeningeal Gliomatosis: Dynamic Changes in Brain MRI

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare and fatal disease with no special clinical manifestations. Here, we report the dynamic brain magnetic resonance imaging (MRI) changes in a 30-year-old female PDLG patient over a 10-month period. MRI showed aggressive dilation of the subarachnoid space and the ventricular system, numerous encapsulated cysts in the subarachnoid space and the dilated cerebral sulci, diffuse reticulated or focal nodular enhancement in the subarachnoid space, as well as overall enhancement in the cystic walls. In addition to the aforementioned PDLG pathological findings, MRI also revealed non-contrasted solid lesions and a contrasted cyst-like lesion in the paraventricular areas. The dynamic and multiform neuroradiological changes help us to understand the pathological process of PDLG. Of particular interest is the discovery that parenchymal infiltration can occur in PDLG.

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

INTRODUCTION

Diffuse leptomeningeal glioneuronal tumor is a new entity under the neuronal and mixed neuronal-glial tumors in the WHO 2016 updated classification and commonly found in children and adolescents. The initial diagnosis is challenging because of its non-specific radiologic feature and negative CSF cytology analysis. A 17 years male was presented with intractable headache subsequently followed by back pain and joint pain. MRI showed enhancement of arachnoid membrane at basal cistern, bilateral sylvian fissure and cerebral cistern with slight enlargement of ventricles. There were no evidences of infection in CSF and blood samples. Based on the duodenal biopsy and prodromal symptom of joint pain, the patient was suspected of having Whipple's disease. Eleven months after the onset, a small mass lesion was observed at the anterior horn of right lateral ventricle. The histology was remarkable for anaplastic oligodendroglioma. Immunostainings revealed positivity for GFAP, Olig2, synaptophysin and negativity for IDH1 mutation, H3K27M. MIB1 labeling index was 40% and 1p19q FISH analysis showed only 1p deletion. Therefore, a final diagnosis of DLGNT was made.

CONCLUSION

DLGNT should be included as a differential diagnosis of patients with leptomeningeal-enhanced and high CSF protein level with normal white blood cell count.

Spinal Anaplastic Oligodendroglioma With Oligodendrogliomatosis: Molecular Markers and Management: Case Report

BACKGROUND AND IMPORTANCE

Spinal cord oligodendrogliomas are rare tumors, with a reported incidence varying between 0.8% and 4.7% of all spinal cord tumors and just over 50 cases reported in the literature. Of these, only 9 cases are histologically defined as anaplastic oligodendrogliomas, with few having complete molecular characterization. The diffuse tumor spread that can occur along the subarachnoid space with secondary invasion of the leptomeninges is called oligodendrogliomatosis and is associated with poor outcome.

CLINICAL PRESENTATION

A 68-year-old man with a history of lumbar stenosis status after lumbar decompression presented with new-onset right lower-extremity weakness. Magnetic resonance imaging demonstrated an intramedullary lesion from T9 to T12. During an attempted diagnostic biopsy, numerous intradural intramedullary lesions not present on magnetic resonance imaging were observed. Tissue biopsy demonstrated a 1p/19q-codeleted anaplastic oligodendroglioma with diffuse oligodendrogliomatosis. Postoperative treatment included 39.2-Gy radiation over 22 fractions from T1 to the bottom of the thecal sac with a boost to the T9-T12 area, the primary site of disease, to a total dose of 43.2 Gy in 24 fractions, followed by adjuvant temozolomide at a dose of 200 mg/m on days 1 to 5 in a 28-day cycle. At the 1-year follow-up, the patient demonstrated moderate neurological improvement.

CONCLUSION

Management, prognosis, and use of molecular data in the decision-making algorithm for these patients are discussed, together with a review of all cases of primary intradural intramedullary spinal anaplastic oligodendrogliomas reported to date. Our study indicates that the combination of sequential treatment with radiation and temozolomide might provide a favorable outcome in the case of 1p/19q-codeleted spinal anaplastic oligodendrogliomas and that molecular analysis can be beneficial in guiding treatment strategies, although the impact of IDH mutations on these tumors is still unclear.

IMAGING DIAGNOSIS-MAGNETIC RESONANCE IMAGING OF DIFFUSE LEPTOMENINGEAL OLIGODENDROGLIOMATOSIS IN A DOG WITH "DURAL TAIL SIGN"

A case of diffuse leptomeningeal oligodendrogliomatosis affecting the brain and spinal cord of a dog is presented. A 7.5-year old, male neutered Staffordshire bull terrier presented for evaluation of a chronic history of tetraparesis and seizures, with a multifocal neuroanatomical localization was determined. Extra-axial intradural lesions with an atypical presentation of a dural tail sign were seen on MRI. Histologically, the lesions were consistent with leptomeningeal oligodendrogliomatosis. To the authors' knowledge, a dural tail sign has not previously been reported as an MRI characteristic of diffuse leptomeningeal oligodendrogliomatosis in dogs.

Imaging of oligodendroglioma

Oligodendroglioma are glial tumours, predominantly occurring in adults. Their hallmark molecular feature is codeletion of the 1p and 19q chromosome arms, which is not only of diagnostic but also of prognostic and predictive relevance. On imaging, these tumours characteristically show calcification, and they have a cortical–subcortical location, most commonly in the frontal lobe. Owing to their superficial location, there may be focal thinning or remodelling of the overlying skull. In contrast to other low-grade gliomas, minimal to moderate enhancement is commonly seen and perfusion may be moderately increased. This complicates differentiation from high-grade, anaplastic oligodendroglioma, in which enhancement and increased perfusion are also common. New enhancement in a previously non-enhancing, untreated tumour, however, is suggestive of malignant transformation, as is high growth rate. MR spectroscopy may further aid in the differentiation between low- and high-grade oligodendroglioma. A relatively common feature of recurrent disease is leptomeningeal dissemination, but extraneural spread is rare. Tumours with the 1p/19q codeletion more commonly show heterogeneous signal intensity, particularly on T₂ weighted imaging; calcifications; an indistinct margin; and mildly increased perfusion and metabolism than 1p/19q intact tumours. For the initial diagnosis of oligodendroglioma, MRI and CT are complementary; MRI is superior to CT in assessing tumour extent and cortical involvement, whereas CT is most sensitive to calcification. Advanced and functional imaging techniques may aid in grading and assessing the molecular genotype as well as in differentiating between tumour recurrence and radiation necrosis, but so far no unequivocal method or combination of methods is available.

Cranial and spinal oligodendrogliomatosis: a case report and review of the literature

INTRODUCTION

Oligodendrogliomatosis is a rarely reported entity in literature associated with poor prognosis in terms of length and quality of life. In this paper, we describe oligodendrogliomatosis in a 15-year-old male who initially presented with altered mental status due to diabetic ketoacidosis.

CLINICAL PRESENTATION

He was refractory to temozolomide initially but demonstrated disease regression with radiotherapy (XRT). More recently, he has had disease recurrence, which was stabilized with temozolomide therapy for a period of time.

CONCLUSION

Contrary to most reports in literature, our patient has had excellent quality of life since his initial diagnosis and continues to carry good prognosis. In addition to oligodendrogliomatosis, our patient also developed multiple intracranial cavernomas secondary to radiation therapy, which have remained stable and asymptomatic.

Disseminated oligodendroglial-like leptomeningeal tumor with anaplastic progression and presumed extraneural disease: case report

We report the neuroimaging and histopathologic findings of a 12-year-old female patient with a disseminated oligodendroglial-like leptomeningeal tumor with anaplastic progression and presumed extraneural metastatic disease. These tumors may represent distinct pathology primarily seen in pediatric patients. Neuroimaging demonstrates diffuse, progressive enhancement of the leptomeninges often with interval development of intraparenchymal lesions on follow-up. Disease is typically confined to the central nervous system, though diffuse peritoneal disease was seen in our case, possibly through metastatic seeding of the abdomen via ventriculoperitoneal shunt.

Spinal Meningeal Oligodendrogliomatosis in Two Boxer Dogs

Two Boxer dogs developed progressive ataxia in association with a neoplastic infiltration of the spinal leptomeninges. In the first dog, the leptomeningeal neoplasm encompassed the entire cord and the ventral aspect of the brainstem and extended bilaterally into the piriform lobes. In the second, the neoplasm surrounded the C1–C3 segments of the spinal cord and the brainstem without involvement of the brain or spinal cord parenchyma. In both dogs, the neoplastic cells had variably distinct cell borders, clear to eosinophilic cytoplasm, and a round to ovoid hyperchromatic nucleus. Neoplastic cells were immunopositive for Olig2 and doublecortin in both dogs and for vimentin in one dog but were immunonegative for glial fibrillary acidic protein, S-100, CD34, E-cadherin, cytokeratin, CD3, and CD20. The morphological and immunohistochemical features of the neoplastic cells were consistent with an oligodendrocyte lineage. This hitherto poorly recognized neoplasm in dogs is analogous to human leptomeningeal oligodendrogliomatosis.

Disseminated oligodendroglial-like leptomeningeal tumor of childhood: a distinctive clinicopathologic entity

Rare, generally pediatric oligodendroglioma-like neoplasms with extensive leptomeningeal dissemination have been interpreted variably as glial, oligodendroglial or glioneuronal. The clinicopathologic features have not been fully characterized. We studied 36 patients, 12 females and 24 males with a median age of 5 years (range 5 months-46 years). MRI demonstrated leptomeningeal enhancement, frequently with cystic or nodular T2 hyperintense lesions within the spinal cord/brain along the subpial surface. A discrete intraparenchymal lesion, usually in the spinal cord, was found in 25 (of 31) (81 %). Tumors contained oligodendroglioma-like cells with low-mitotic activity (median 0 per 10 high power fields, range 0-4), and rare ganglion/ganglioid cells in 6 cases (17 %). Tumors were mostly low-grade, with anaplastic progression in 8 (22 %). Immunohistochemistry demonstrated strong reactivity for OLIG2 (7 of 9) (78 %), and moderate/strong S100 (11 of 12) (92 %), GFAP (12 of 31) (39 %) and synaptophysin (19 of 27) (70 %). NeuN, EMA, and mutant IDH1 (R132H) protein were negative. Median MIB1 labeling index was 1.5 % (range <1-30 %). FISH (n = 13) or SNP array (n = 2) demonstrated 1p loss/intact 19q in 8 (53 %), 1p19q co-deletion in 3 (20 %), and no 1p or 19q loss in 4 (27 %). Clinical follow-up (n = 24) generally showed periods of stability or slow progression, but a subset of tumors progressed to anaplasia and behaved more aggressively. Nine patients (38 %) died 3 months-21 years after diagnosis (median total follow-up 5 years). We report a series of a neoplasm with distinct clinicopathologic and molecular features. Although most progress slowly, a significant fraction develop aggressive features.

Pineocytoma with diffuse dissemination to the leptomeninges

Pineal parenchymal tumors are rare. Of the three types of pineal parenchymal tumors, pineocytomas are the least aggressive and are not known to diffusely disseminate. In this paper, we report the successful treatment of a case of pineocytoma with diffuse leptomeningeal relapse following initial stereotactic radiotherapy. A 39-year-old female presented with headaches, balance impairment, urinary incontinence, and blunted affect. A pineal mass was discovered on magnetic resonance imaging (MRI). A diagnosis of pineocytoma was established with an endoscopic pineal gland biopsy, and the patient received stereotactic radiotherapy. Ten years later, she developed diffuse leptomeningeal dissemination. The patient was then successfully treated with craniospinal radiation therapy. Leptomeningeal spread may develop as late as 10 years after initial presentation of pineocytoma. Our case demonstrates the importance of long-term follow-up of patients with pineal parenchymal tumors following radiation therapy, and the efficacy of craniospinal radiation in the treatment of leptomeningeal dissemination.