Neoplastic meningitis: How MRI and CSF cytology are influenced by CSF cell count and tumor type

Case report: MRI and CT imaging features of a melanocytic tumour affecting a cervical vertebra in an adult dog, and review of differential diagnosis for T1W-hyperintense lesions

A 7-year-old Lhasa Apso presented with a history of left thoracic limb lameness and neck pain. Magnetic resonance imaging revealed a well-defined, extradural lesion that was hyperintense on T1-weighted (T1W) images and isointense on T2-weighted (T2W) images and T2* images located at the left lamina of the C4 vertebra. Computed tomography showed an isoattenuating and contrast-enhancing mass centered on the left C4 vertebral lamina with associated osteolysis. The mass was surgically debulked, and histopathology revealed a malignant melanocytic tumour. The patient recovered completely and received radiotherapy and three doses of the melanoma vaccine as adjunctive treatment. Eighteen months following treatment, the patient presented with neck pain again, but further investigations were declined at this stage, and the patient was euthanised. To the author's knowledge, this is the first case report describing the imaging characteristics of a cervical extradural melanocytic tumour in a dog. This case illustrates the MRI and CT imaging features and treatment of a canine melanocytic tumour of the cervical vertebrae.

MRI manifestations of central nervous system leukaemia and cytological analysis of the cerebrospinal fluid

AIM

To investigate the magnetic resonance imaging (MRI) features and explore the value of MRI in the diagnosis of central nervous system leukaemia (CNSL).

MATERIALS AND METHODS

A retrospective study was performed in 68 patients with leukaemia who underwent cranial MRI between January 2020 and June 2022 at Institute of Hematology and Blood Diseases Hospital.

RESULTS

A total of 33 patients fulfilled the requirements for inclusion. The findings showed that 87.9% patients exhibited neurological symptoms, and 23 patients showed abnormal MRI findings. No differences were observed between the MRI+ and MRI- groups in terms of age, sex, neurological symptoms, glucose in the cerebrospinal fluid (CSF), chloride in the CSF, abnormal cells detected using conventional cytology (CC), bone marrow status at the diagnosis of CNSL, signal intensity ratio, and mortality, except for protein concentration and the number of leukaemic cells detected using flow cytometry (FCM) in the CSF. Kaplan-Meier survival analysis in patients with leukaemia revealed no statistical differences in the median survival times between the MRI+ group and MRI- group. Cox regression analysis and multivariate analysis showed no significant difference in survival rate between the MRI+ and MRI- groups. Kappa consistency test shows weak diagnostic consistency between MRI and CC, and weak diagnostic inconsistency between MRI and FCM.

CONCLUSION

MRI could serve as an important complementary tool to CC and FCM in the diagnosis of CNSL, especially in patients without leptomeningeal involvement.

Multidisciplinary management of patients with non-small cell lung cancer with leptomeningeal metastasis in the tyrosine kinase inhibitor era

OBJECTIVE

Leptomeningeal metastasis (LM) is a challenging scenario in non-small cell lung cancer (NSCLC). Considering that outcomes of treatment modalities stratified by LM chronological patterns related to brain metastasis (BM) are lacking, the aim of this study was to evaluate outcomes and explore prognostic factors.

METHODS

The authors retrospectively collected data of patients with NSCLC undergoing Ommaya reservoir implantation, ventriculoperitoneal shunt implantation, or lumboperitoneal shunt implantation. Based on radiographic findings and time from diagnosis of NSCLC to LM, the authors divided them into subtypes of LM as follows: LM without BM; LM concurrent with BM; or LM after BM. The Kaplan-Meier method was applied to analyze overall survival (OS) and multivariate Cox regression for prognostic factors.

RESULTS

Sixty-one patients with LM were included, with a median OS of 8.1 (range 0.2-70.0) months. Forty-three (70.5%) patients had EGFR-mutant disease. Forty-two (68.9%) patients had 19-del or L858R mutation, and one (1.6%) patient had G719A mutation. Fifty-seven (93.4%) patients had hydrocephalus. Twenty-one (34.4%) patients received whole-brain radiotherapy before LM diagnosis, 3 (4.9%) patients underwent operation for BMs before LM diagnosis, and 42 (68.9%) patients received EGFR tyrosine kinase inhibitor (TKI) therapy before LM diagnosis. Eleven patients were treated with chemotherapy, 10 patients were treated with TKIs, and 32 patients were treated with chemotherapy combined with TKIs before LM diagnosis. Patients with LM after BM had lower Karnofsky Performance Status (KPS) scores (KPS score 50) than did those with LM without BM (KPS score 80) or LM concurrent with BM (KPS score 70; p = 0.003). More patients with LM after BM received intrathecal methotrexate than in the other subgroups (p < 0.001). The median OS was significantly shorter in the LM after BM than in the concurrent LM and BM and the LM without BM subgroups (5.4 vs 5.5 vs 11.6 months; p = 0.019). Cox regression revealed that a KPS score ≥ 70 (HR 0.51; p = 0.027) and shunt implantation (HR 0.41; p = 0.032) were favorable prognostic factors.

CONCLUSIONS

Patients with NSCLC who had LM without BM had better survival outcomes (11.6 months) compared with those who had LM after BM or concurrent LM and BM. Aggressive shunt implantation may be favored for LM.

Assessing CSF ctDNA to improve diagnostic accuracy and therapeutic monitoring in breast cancer leptomeningeal metastasis

PURPOSE

Cerebrospinal fluid (CSF) cytology is the gold standard diagnostic test for breast cancer leptomeningeal metastasis (BCLM), but has impaired sensitivity, often necessitating repeated lumbar puncture to confirm or refute diagnosis. Further, there is no quantitative response tool to assess response or progression during BCLM treatment.

EXPERIMENTAL DESIGN

Facing the challenge of working with small volume samples and the lack of common recurrent mutations in breast cancers, cell-free DNA was extracted from CSF and plasma of patients undergoing investigation for BCLM (n=30). ctDNA fraction was assessed by ultra-low pass whole genome sequencing (ulpWGS), which does not require prior tumor sequencing.

RESULTS

In this proof-of-concept study ctDNA was detected (fraction {greater than or equal to}0.10) in CSF of all 24 BCLM+ patients (median ctDNA fraction 0.57), regardless of negative cytology or borderline MRI imaging, whereas CSF ctDNA was not detected in the 6 BCLM- patients (median ctDNA fraction 0.03, P<0.0001). Plasma ctDNA was only detected in patients with extracranial disease progression or who had previously received whole brain radiotherapy. ctDNA fraction was highly concordant with mutant allele fraction measured by tumor mutation-specific ddPCR assays (r=0.852, P<0.0001). During intrathecal treatment, serial monitoring (n=12 patients) showed that suppression of CSF ctDNA fraction was associated with longer BCLM survival (P=0.034) and rising ctDNA fraction was detectable up to 12 weeks before clinical progression.

CONCLUSION

Measuring ctDNA fraction by ulpWGS is a quantitative marker demonstrating potential for timely and accurate BCLM diagnosis and therapy response monitoring, with the ultimate aim to improve management of this poor prognosis patient group.

Leptomeningeal disease from melanoma-Poor prognosis despite new therapeutic modalities

OBJECTIVE

The development of leptomeningeal disease (LMD) among melanoma patients is associated with short survival. Unspecific clinical symptoms and imprecise diagnostic criteria often delay diagnosis. Because melanoma patients with LMD have been excluded from most clinical trials, the efficacy of immune checkpoint blockade (ICB) and targeted therapies (TTs) has not been adequately investigated among these patients.

METHODS

We performed a retrospective study in two tertiary-referral skin cancer centres to evaluate the clinical characteristics, diagnostics, treatments, and overall survival (OS) of melanoma patients with LMD between June 2011 and March 2019.

RESULTS

In total, 52 patients were included. The median age at LMD diagnosis was 58 years. Most patients (n = 30, 58%) were men. The median time from the first diagnosis of unresectable disease to the first diagnosis of LMD was 8.5 months (range 0-91.5 months). Most patients (65%, n = 34) were BRAF V600 mutated. Sixteen patients (31%) presented with LMD only, whereas 36 patients (69%) presented with concomitant brain metastases at LMD diagnosis. Eleven patients (21%) showed no evidence of extracranial disease. Forty-four patients (85%) had clinical symptoms at LMD diagnosis. Forty-two patients (81%) had received at least one prior therapy. Forty patients (77%) received at least one treatment after LMD diagnosis, including TT (n = 17), ICB (n = 13), bevacizumab (n = 1), radiotherapy (n = 3), and intrathecal chemotherapy (n = 1); five patients received both TT and ICB. Twelve patients (23%) received no treatment because of rapid progression of LMD. The median OS for the entire cohort was 2.9 months (95% confidence interval [CI] 1.7-4.1). Among patients receiving systemic therapy, OS was 3.7 months (95% CI 2.4-4.9).

CONCLUSIONS

Systemic treatment with TT or ICB seems to improve OS among patients with LMD. However, despite new therapy modalities, the prognosis of LMD remains poor.

Leptomeningeal Metastasis: The Role of Cerebrospinal Fluid Diagnostics

Background: Metastatic spread into the cerebrospinal fluid (CSF) represents a severe complication of malignant disease with poor prognosis. Although early diagnosis is crucial, broad spectrums of clinical manifestations, and pitfalls of magnetic resonance imaging (MRI) and CSF diagnostics can be challenging. Data are limited how CSF parameters and MRI findings relate to each other in patients with leptomeningeal metastasis.

Methods: Patients with malignant cells in CSF cytology examination diagnosed between 1998 and 2016 at the Department of Neurology in the Hannover Medical School were included in this study. Clinical records, MRI findings and CSF parameters were retrospectively analyzed.

Results: One hundred thirteen patients with leptomeningeal metastasis were identified. Seventy-six patients (67%) suffered from a solid malignancy while a hematological malignancy was found in 37 patients (33%). Cerebral signs and symptoms were most frequently found (78% in solid vs. 49% in hematological malignancies) followed by cranial nerve impairment (26% in solid vs. 46% in hematological malignancies) and spinal symptoms (26% in solid vs. 27% in hematological malignancies). In patients with malignant cells in CSF MRI detected signs of leptomeningeal metastasis in 62% of patients with solid and in only 33% of patients with hematological malignancies. Investigations of standard CSF parameters revealed a normal CSF cell count in 21% of patients with solid malignancies and in 8% of patients with hematological malignancies. Blood-CSF-barrier dysfunction was found in most patients (80% in solid vs. 92% in hematological malignancies). Elevated CSF lactate levels occurred in 68% of patients in solid and in 48% of patients with hematological malignancies. A high number of patients (30% in solid vs. 26% in hematological malignancies) exhibited oligoclonal bands in CSF. Significant correlations between the presence of leptomeningeal enhancement demonstrated by MRI and CSF parameters (cell count, lactate levels, and CSF/Serum albumin quotient) were not found in both malignancy groups.

Conclusion: CSF examination is helpful to detect leptomeningeal metastasis since the diagnosis can be challenging especially when MRI is negative. CSF cytological investigation is mandatory whenever leptomeningeal metastasis is suspected, even when CSF cell count is normal.

Meningeal enhancement depicted by magnetic resonance imaging in tumor patients: neoplastic meningitis or therapy-related enhancement?

PURPOSE

To assess the prevalence of false-positive meningeal contrast enhancement in patients with solid tumors who were undergoing chemotherapy.

METHODS

A total of 2572 magnetic resonance imaging (MRI) examinations of the brain were retrospectively evaluated by two readers for the presence of pathological meningeal contrast enhancement conspicuous for neoplastic meningitis. These patients either had malignant melanoma, breast or lung cancer, or lymphoma. The reference standards were cerebrospinal fluid cytology results and follow-up MRI. In cases with pathological contrast enhancement that decreased upon follow-up and non-malignant cytology, the enhancement pattern was further described as pial or dural, local or diffuse, or supra- or infra-tentorial. Moreover, the underlying therapy regimes were assessed.

RESULTS

The final study cohort included 78 patients (51 females, median age 57 years), of which 11 patients (14.1%) had a repeated non-malignant cytology ('pseudomeningeosis'). In one case, this finding, a granular pleocytosis, was attributed to previous radiotherapy. Of the remaining patients, seven were receiving multimodal, immunotherapy-based therapy regimens. Patients with unsuspicious cytology had a predominantly supratentorial distribution pattern in comparison to patients with neoplastic meningitis.

CONCLUSIONS

The overall prevalence of the presence of false-positive meningeal contrast enhancement is low (< 1%) and not associated with specific imaging patterns. We hypothesize that there is a possible relationship between immunotherapy and 'pseudomeningeosis'. Therefore, in all cases with suspected neoplastic meningitis, the cerebrospinal fluid should be analyzed to confirm the diagnosis, especially in patients undergoing immunotherapy.

Immune-mediated neuropathies

Since the discovery of an acute monophasic paralysis, later coined Guillain-Barré syndrome, almost 100 years ago, and the discovery of chronic, steroid-responsive polyneuropathy 50 years ago, the spectrum of immune-mediated polyneuropathies has broadened, with various subtypes continuing to be identified, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). In general, these disorders are speculated to be caused by autoimmunity to proteins located at the node of Ranvier or components of myelin of peripheral nerves, although disease-associated autoantibodies have not been identified for all disorders. Owing to the numerous subtypes of the immune-mediated neuropathies, making the right diagnosis in daily clinical practice is complicated. Moreover, treating these disorders, particularly their chronic variants, such as CIDP and MMN, poses a challenge. In general, management of these disorders includes immunotherapies, such as corticosteroids, intravenous immunoglobulin or plasma exchange. Improvements in clinical criteria and the emergence of more disease-specific immunotherapies should broaden the therapeutic options for these disabling diseases.

Neoplastic meningitis in solid tumors: from diagnosis to personalized treatments

Neoplastic meningitis (NM) is a devastating complication of solid tumors with poor outcome. Some randomized clinical trials have been conducted with heterogeneous inclusion criteria, diagnostic parameters, response evaluation and primary endpoints. Recently, the Leptomeningeal Assessment in Neuro-Oncology (LANO) Group and the European Society for Medical Oncology/European Association for Neuro-Oncology have proposed some recommendations in order to provide diagnostic criteria and response evaluation scores for NM. The aim of these guidelines is to integrate the neurological examination with magnetic resonance imaging and cerebrospinal fluid findings as well as to provide a framework for use in clinical trials. However, this composite assessment needs further validation. Since intrathecal therapy represents a treatment with limited efficacy in NM, many studies have been conducted on systemic therapies, including target therapies, with some encouraging results in terms of disease control. In this review, we have analyzed the clinical aspects and the most recent diagnostic tools and therapeutic options in NM.

Intracranial Leptomeningeal Carcinomatosis: A Diagnostic Study with 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Leptomeningeal carcinomatosis (LC) diagnosis is based on cerebrospinal fluid (CSF) cytological analysis and contrast-enhanced magnetic resonance imaging (MRI); however, low sensitivity was evidenced in some cases delaying prompt and adequate treatments. Brain ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) was also employed in doubtful cases. We retrospectively described 4 suspected LC cases with uncertain or undetectable MRI and initially negative CSF cytology. Whole-body (WB) and brain ¹⁸F-FDG PET/computed tomography (CT) were used, the latter showing intracranial tracer uptakes suspected for LC in 3/4 cases. In 2 of these 3 cases, WB scan also evidenced spinal cord lesion and pulmonary tumor, respectively, while both procedures were true negative in the fourth case. CSF cytology became positive after repeated exams in the 3 PET/CT-positive cases. In 1 of these 3 patients, it was also confirmed at MRI, while it stayed negative in the remaining PET/CT-negative case with uncertain MRI. ¹⁸F-FDG PET/CT could be a useful supportive diagnostic tool in doubtful intracranial and spinal LC.

Overview of metastatic disease of the central nervous system

In 2016, the American Society of Clinical Oncology reported that 1.7 million Americans were diagnosed with cancer; this number will rise to 2.3 million in the United States and 22 million worldwide in 2030. This rising need is being met by an explosion of new cancer therapies, including: immune checkpoint inhibitors, T-cell therapies, tumor vaccines, antiangiogenic therapies, and various targeted therapies. This armamentarium of targeted therapies has led to better systemic control of disease and longer patient overall survival (OS). The incidence of metastatic disease to the central nervous system (CNS) is rising as patients are living longer with these more effective systemic therapies. Prolonged OS allows increased time to develop CNS metastases. The CNS is also a sanctuary for metastatic tumor cells that are protected from full exposure to therapeutic concentrations of most anticancer agents by the blood-brain barrier, the tumor microenvironment, and immune system. In addition, CNS metastases often develop late in the course of the disease, so patients are frequently heavily pretreated, resulting in drug resistance. Although genomic profiling has led to more effective therapies for systemic disease, the same therapy may not be effective in treating CNS disease, not only due to failure of blood-brain barrier penetration, but from discordance between the molecular profile in systemic and CNS tumor.

A Retrospective Analysis of the Clinical Outcomes of Leptomeningeal Metastasis in Patients with Solid Tumors

Background

Leptomeningeal metastasis (LM) is an uncommon, but devastating complication of advanced cancer and has no standard treatment. Herein, we analyzed the clinical characteristics and outcomes of patients with solid tumors who were diagnosed with LM.

Methods

Between January 2007 and December 2017, we retrospectively analyzed the medical records of patients with solid tumors who were diagnosed with LM.

Results

A total of 58 patients were enrolled in this study. The median age of patients was 51 years (range, 27–72 years), and 62.1% had a poor Eastern Cooperative Oncology Group (ECOG) performance status (PS) (>2). The common types of primary tumor were breast cancer (39.7%), gastric cancer (25.9%), and non-small cell lung cancer (20.7%). Forty-two patients (72.4%) were diagnosed with LM by MRI of the brain and/or spine and cerebrospinal fluid (CSF) analysis, 14 were diagnosed by CSF analysis alone, and 2 were diagnosed by MRI alone. Treatments for LM were performed in 53 patients (91.4%), and best supportive care was provided for 5 patients (8.6%). Intrathecal chemotherapy, radiotherapy, and systemic chemotherapy were administered in 43 (74.1%), 17 (29.3%), and 24 (41.4%) patients, respectively. The median overall survival of the entire cohort was 2.4 months (95% confidence interval, 1.0–3.7). In the analysis of prognostic factors for survival, a good ECOG PS (≤2), administration of systemic chemotherapy after LM diagnosis, and a prior history of brain radiation were associated with prolonged survival.

Conclusion

Although the prognosis of LM in patients with solid tumors is poor, systemic chemotherapy might improve survival in selected patients with a good PS.

Profiling of metalloprotease activities in cerebrospinal fluids of patients with neoplastic meningitis

Background

Neoplastic invasion into leptomeninges and subarachnoid space, resulting in neoplastic meningitis (NM) is a fatal complication of advanced solid and hematological neoplasms. Identification of malignant involvement of the cerebrospinal fluid (CSF) early in the disease course has crucial prognostic and therapeutic implications, but remains challenging. As indicators of extracellular matrix (ECM) degradation and breakdown of the blood–brain-barrier, Matrix Metalloproteases (MMPs) and A Disintegrin and Metalloproteases (ADAMs) are potential analytes for cerebral pathophysiology and metastatic dissemination of tumor cells into the CSF.

Methods

We compared protease activities in CSF samples from patients with NM and control individuals using FRET-based metalloprotease substrates with distinct enzyme selectivity profiles in a real-time, multiplex approach termed “proteolytic activity matrix assay” (PrAMA). Protease activity dynamics can be tracked by fluorescence changes over time. By simultaneously monitoring a panel of 5 FRET-substrate cleavages, a proteolytic signature can be identified and analyzed to infer the activities of multiple specific proteases. Distinct patterns of substrate cleavage comparing disease vs. control samples allow rapid, reproducible and sensitive discrimination even in small volumes of CSF.

Results

Individual substrate cleavage rates were linked to distinct proteases, and PrAMA computational inference implied increased activities of MMP-9, ADAM8 and ADAM17 (4–5-fold on average) in CSF samples from NM patients that were inhibitable by the metalloprotease inhibitor batimastat (BB-94). The activities of these proteases correlated with blood–brain barrier impairment. Notably, CSF cell counts were not found to directly reflect the protease activities observed in CSF samples from NM patients; this may explain the frequent clinical observation of negative cytology in NM patients.

Conclusion

PrAMA analysis of CSF samples is a potential diagnostic method for sensitive detection of NM and may be suitable for the clinical routine.

Electronic supplementary material

The online version of this article (doi:10.1186/s12987-017-0070-5) contains supplementary material, which is available to authorized users.

Role of neuroimaging in children with acute lymphoblastic leukemia and central nervous system involvement at diagnosis

BACKGROUND

Each year approximately 200 children and adolescents are diagnosed with acute lymphoblastic leukemia (ALL) in the five Nordic countries, and 3% of these have central nervous system (CNS) involvement confirmed by leukemic cells in the cerebrospinal fluid (CSF) or neurological symptoms. We sought to determine the significance of neuraxis imaging in such patients.

PROCEDURE

Magnetic resonance images of children aged 1-17.9 with CNS leukemia at diagnosis of ALL were centrally reviewed and clinical data were retrieved from the medical records and the Nordic leukemia registry. Patients were diagnosed in the period 2000-2012 in Sweden, Finland, or Denmark.

RESULTS

The cohort comprised 1,877 patients, and 66 (3.5%) had CNS involvement. Forty-five percent (30/66) had CNS related symptoms. Symptoms included vomiting, facial palsy, headache, visual symptoms, and impaired hearing. CNS imaging was performed in 32 of 66 children (48%), and confirmed CNS involvement in 6 of 21 patients with symptoms (29%) and 5 of 11 (45%) without (P = 0.44). There was no difference in the overall survival between CNS-positive patients with and without signs of leukemic involvement by imaging (P = 0.53).

CONCLUSIONS

Radiological imaging of asymptomatic children with CNS leukemia at diagnosis lacks clinical importance, but may be useful in patients with cranial nerve symptoms and negative CSF, as well as for follow-up. Imaging of symptomatic patients is warranted in order to exclude other causes underlying the symptoms.

How to facilitate early diagnosis of CNS involvement in malignant lymphoma

INTRODUCTION

Making the diagnosis of secondary CNS involvement in lymphoma can be difficult due to unspecific signs and symptoms, limited accessibility of brain/myelon parenchyma and low sensitivity and/or specifity of imaging and cerebrospinal fluid (CSF) examination currently available. Areas covered: MRI of the total neuroaxis followed by CSF cytomorphology and flow cytometry are methods of choice when CNS lymphoma (CNSL) is suspected. To reduce the numerous pitfalls of these examinations several aspects should be considered. New CSF biomarkers might be of potential diagnostic value. Attempts to standardize response criteria are presented. Expert commentary: Diagnosing CNSL remains challenging. Until diagnostic methods combining high sensitivity with high specifity are routinely introduced, high level of awareness and optimal utilization of examinations currently available are needed to early diagnose this potentially devastating disease.