Nonenhancing Leptomeningeal Metastases: Imaging Characteristics and Potential Causative Factors

A non-enhancing, T2 fluid-attenuated inversion recovery hyperintense, diffusion-restricting brainstem lesion in an EGFR tyrosine kinase inhibitor-treated non-small-cell lung cancer patient

Leptomeningeal metastasis (LM) is a devastating complication of malignancy. Diagnosis relies on both contrast enhancement on imaging and malignant cells in cerebral spinal fluid cytology. Though early detection and prompt intervention improves survival, the detection of LM is limited by false negatives. A rare brainstem imaging finding uncovered specifically in EGFR mutation-positive lung cancer patients may represent an early sign of LM. This sign demonstrates high signal on T2 fluid-attenuated inversion recovery and diffusion-weighted imaging sequences, but paradoxically lacks correlative contrast enhancement. Here we report a case of a 72-year-old female EGFR-positive lung cancer patient who developed this lesion following treatment with two first-generation EGFR tyrosine kinase inhibitors then showed subsequent response to osimertinib, an irreversible third-generation EGFR tyrosine kinase inhibitor.

Extraordinary linear non-enhancing brainstem leptomeningeal metastasis from lung adenocarcinoma: A case report

In patients with lung adenocarcinoma, angiogenesis-altering drugs can alter the appearance of leptomeningeal metastasis on magnetic resonance imaging (MRI) scans. In the ventral brainstem, this can manifest as a unique, linear, non-enhancing T2-hyperintense signal.

Detection of Leptomeningeal Carcinomatosis by Cerebrospinal Fluid in a Dog with a Negative MRI

An 11 yr old female French bulldog was presented for acute onset of seizures and a 2 wk history of disorientation. On physical examination, a nodular mass at the fourth mammary gland level was observed. Neurological evaluation showed obtundation and compulsive behavior. Brain MRI study did not reveal any abnormalities. Cerebrospinal fluid (CSF) collected from the cerebellomedullary cistern showed a marked increase of total nucleated cell count (400 cells/μL). Cytological evaluation identified the presence of a monomorphic round cell population characterized by large cell bodies, a single eccentrical located nucleus with high nuclear:cytoplasmatic ratio, and marked atypia with anisocytosis, anisokaryosis, and multiple nucleoli. Leptomeningeal carcinomatosis (LC) was suspected. The dog was euthanatized for worsening of clinical signs. Post-mortem examination identified an anaplastic mammary carcinoma in the nodular mammary mass. Infiltration by neoplastic cells exhibiting the same morphological features was detected along leptomeninges of the telencephalon and cerebellum associated with cortical and subcortical parenchymal micrometastases. To our knowledge, this is the first case of LC in a dog detected by CSF evaluation but without any MRI abnormalities. This finding emphasizes the usefulness of CSF cytology in patients with suspected LC even in the absence of any MRI identifiable lesions.

Band-Like Brainstem Lesion in a Patient With a History of Lung Adenocarcinoma

Leptomeningeal metastasis (LM) is a severe complication of primary malignancy that has spread to the leptomeninges and cerebrospinal fluid (CSF). Here, we report a patient whose magnetic resonance imaging (MRI) showed a unique brainstem lesion suspicious of LM. A 72-year-old man presented with dizziness, gait instability, and cognitive decline, primarily object naming. He had a history of lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation. Brain MRI revealed a band-like lesion surrounding the ventral brainstem with T2 weighted-image/fluid attenuation inversion recovery (FLAIR) imaging and diffusion-weighted imaging (DWI) hyperintensity without gadolinium enhancement. No malignant cells were detected in the CSF. He underwent ventriculoperitoneal shunt two months after the onset, and his gait improved, but his cognitive function declined further. Recent reports suggest similar brainstem lesions as a unique LM pattern, which occurs almost exclusively in patients with lung adenocarcinoma with EGFR mutation. Therefore, if MRI shows this brainstem finding, repeated and appropriate CSF cytology is needed to detect tumor cells. Furthermore, if a patient with lung adenocarcinoma shows a cognitive decline, cerebral LM and auto-antibodies that mainly target neuronal surface antigens should be considered.

Neoplastic meningitis in solid tumours: updated review of diagnosis, prognosis, therapeutic management, and future directions

Neoplastic meningitis (NM) is a relatively frequent metastatic complication of cancer associated with high levels of neurological morbidity and generally poor prognosis. It appears in 5%-15% of patients with solid tumours, the most frequent being breast and lung cancer and melanoma. Symptoms are caused by involvement of the cerebral hemispheres, cranial nerves, spinal cord, and nerve roots, and are often multifocal or present with signs and symptoms of intracranial hypertension. The main diagnostic tools are the neurological examination, brain and spinal cord contrast-enhanced magnetic resonance imaging, and cerebrospinal fluid analysis including cytology, although studies have recently been conducted into the detection of tumour cells and DNA in the cerebrospinal fluid, which increases diagnostic sensitivity. With the currently available therapies, treatment aims not to cure the disease, but to delay and ameliorate the symptoms and to preserve quality of life. Treatment of NM involves a multimodal approach that may include radiotherapy, intrathecal and/or systemic chemotherapy, and surgery. Treatment should be individualised, and is based mainly on clinical practice guidelines and expert opinion. Promising clinical trials are currently being conducted to evaluate drugs with molecular and immunotherapeutic targets. This article is an updated review of NM epidemiology, clinical presentation, diagnosis, prognosis, management, and treatment; it is aimed at general neurologists and particularly at neurologists practicing in hospital settings with oncological patients.

Leptomeningeal Carcinomatosis: Molecular Landscape, Current Management, and Emerging Therapies

Leptomeningeal carcinomatosis is a devastating consequence of late-stage cancer, and despite multimodal treatment, remains rapidly fatal. Definitive diagnosis requires identification of malignant cells in the cerebrospinal fluid (CSF), or frank disease on MRI. Therapy is generally palliative and consists primarily of radiotherapy and/or chemotherapy, which is administered intrathecally or systemically. Immunotherapies and novel experimental therapies have emerged as promising options for decreasing patient morbidity and mortality. In this review, the authors discuss a refined view of the molecular pathophysiology of leptomeningeal carcinomatosis, current approaches to disease management, and emerging therapies.

T2-hyperintense, non-gadolinium-enhancing, diffusion-restricted symmetrical curvilinear lesion of the anterior pons: a rare radiological pattern of leptomeningeal metastatic disease secondary to likely lung adenocarcinoma

Leptomeningeal carcinomatosis is a devastating sequelae of metastatic cancer. It has protean manifestations on imaging. An elderly woman presented to our tertiary centre with symptoms suggestive of a cerebrovascular accident. Investigations revealed no evidence of this. There was clinical, contextual and radiological evidence of an underlying neoplasm.Magnetic resonance imaging (MRI) demonstrated evidence of a rare morphology (anterolateral pontine leptomeningeal enhancement) in the presence of a probable concomitant lung adenocarcinoma. Other reports have previously described this same neuroradiology, seemingly always in association with lung adenocarcinoma.The purpose of this report is to highlight an unusual case and discuss its peculiarity and pathophysiology. Our patient is the latest documented of a small cohort with this constellation of clinical and neuroradiological features.This study demonstrates the importance of differential diagnosis in stroke medicine, specifically the need to consider neoplastic phenomena in patients admitted following putative cerebrovascular events.

FLAIR hyperintensity along the brainstem surface in leptomeningeal metastases: a case series and literature review

Background

The incidence of leptomeningeal metastasis (LM) is underestimated because of its non-specific signs and the low sensitivity of clinical diagnostic modalities. Cerebrospinal magnetic resonance (MR) imaging with and without contrast enhancement (CE) is a gold standard for the neuroradiological assessment of patients with suspected LM. Previous studies suggested that some LM cases show changes of the brainstem surface on non-contrast MR images without or before the appearance of abnormalities on CE images. We assessed the features of this non-contrast MR finding in a cohort of LM patients in this retrospective single-institution study.

Methods

We reviewed head MR images and clinical data of 142 consecutive patients in whom the final diagnosis was LM.

Results

We found that 11 of these 142 patients (7.7%) with LM had band-like hyperintensity on the brainstem surface on non-enhanced FLAIR images, which looked like bloomy rind on cheese. Three of seven patients who were examined using diffusion-weighted imaging showed restricted diffusion in the corresponding lesion site. The above-mentioned 11 patients included 10 women and 1 man, with a median age of 61 years. All 11 patients had primary lung adenocarcinoma. Seven patients had symptomatic hydrocephalus. Ten patients had EGFR-mutated and one had ALK-rearrangement adenocarcinomas. Before the diagnosis of LM, 10 patients had undergone systemic therapy with EGFR-TKI or pemetrexed, and 1 patient with ALK inhibitor and bevacizumab.

Conclusions

We present a series of patients with bloomy rind sign that is non-enhancing LM reliably detected by FLAIR hyperintensity on the brainstem surface. This finding is rare, but may reflect the spread of cancer cells in both the leptomeningeal membrane and the surface of the brain parenchyma specifically in patients with lung adenocarcinomas. Further study is needed to determine the clinical significance of this sign, and the pathophysiological factors associated with it may be clarified by analyzing serial MR images in a larger cohort of patients treated for LM.

Neoplastic meningitis in solid tumours: Updated review of diagnosis, prognosis, therapeutic management, and future directions

Neoplastic meningitis (NM) is a relatively frequent metastatic complication of cancer associated with high levels of neurological morbidity and generally poor prognosis. It appears in 5%-15% of patients with solid tumours, the most frequent being breast and lung cancer and melanoma. Symptoms are caused by involvement of the cerebral hemispheres, cranial nerves, spinal cord, and nerve roots, and are often multifocal or present with signs and symptoms of intracranial hypertension. The main diagnostic tools are the neurological examination, brain and spinal cord contrast-enhanced magnetic resonance imaging, and cerebrospinal fluid analysis including cytology, although studies have recently been conducted into the detection of tumour cells and DNA in the cerebrospinal fluid, which increases diagnostic sensitivity. With the currently available therapies, treatment aims not to cure the disease, but to delay and ameliorate the symptoms and to preserve quality of life. Treatment of NM involves a multimodal approach that may include radiotherapy, intrathecal and/or systemic chemotherapy, and surgery. Treatment should be individualised, and is based mainly on clinical practice guidelines and expert opinion. Promising clinical trials are currently being conducted to evaluate drugs with molecular and immunotherapeutic targets. This article is an updated review of NM epidemiology, clinical presentation, diagnosis, prognosis, management, and treatment; it is aimed at general neurologists and particularly at neurologists practicing in hospital settings with oncological patients.

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.

Leptomeningeal dissemination of low-grade neuroepithelial CNS tumors in adults: a 15-year experience

Background

Leptomeningeal dissemination (LD) in adults is an exceedingly rare complication of low-grade neuroepithelial CNS tumors (LGNs). We aimed to determine relative incidence, clinical presentation, and predictors of outcome.

Methods

We searched the quality control database of the Section of Neuro-Oncology, Yale Cancer Center, for patients with LGN (WHO grade I/II) seen between 2002 and 2017. For cases complicated by LD, we recorded demographics, clinical signs, histopathological diagnosis, and imaging findings. A comprehensive literature review was performed.

Results

Eleven consecutive patients with LD were identified, representing 2.3% of individuals with LGN seen at our institution between 2002 and 2017 (n = 475). Ependymoma was the predominant histological entity. Mean time interval from diagnosis of LGN to LD was 38.6 ± 10 months. Symptoms were mostly attributed to communicating hydrocephalus. Tumor deposits of LD were either nodular or linear with variable enhancement (nonenhancing lesions in 4 of 11 patients). Localized (surgery, radiosurgery, involved-field, or craniospinal radiation therapy) or systemic treatments (chemotherapy) were provided. All patients progressed radiographically. Median overall survival after LD was 102 months. Survival was prolonged when a combination of localized and systemic therapies was administered (188.5 vs 25.5 months; P = .03). Demographics and tumor spectrum reported in the literature were similar to our cohort.

Conclusions

LD is a rare complication of LGNs. A high level of suspicion is required for timely diagnosis as early symptoms are nonspecific and commonly do not occur until years after initial tumor diagnosis. Repeated aggressive treatment appears to be beneficial in improving survival.

Intra-operative cerebrospinal fluid sampling versus post-operative lumbar puncture for detection of leptomeningeal disease in malignant paediatric brain tumours

Introduction

Leptomeningeal disease is a feared sequelae of malignant paediatric brain tumours. Current methods for its detection is the combined use of cranio-spinal MRI, and CSF cytology from a post-operative lumbar puncture. In this study, the authors hypothesize that CSF taken at the start of surgery, either from an external ventricular drain or neuroendoscope will have equal sensitivity for positive tumour cells, in comparison to lumbar puncture. Secondary hypotheses include positive correlation between CSF cytology and MRI findings of LMD. From a clinical perspective, the key aim of the study was for affected paediatric patients to avoid an additional procedure of a lumbar puncture, often performed under anaesthesia after neurosurgical intervention.

Methods

This is single-institution, retrospective study of paediatric patients diagnosed with malignant brain tumours. Its main aim was to compare cytological data from CSF collected at the time of surgery versus data from an interval lumbar puncture. In addition, MRI imaging of the same cohort of patients was examined for leptomeningeal disease and corroborated against CSF tumour cytology findings.

Results

Thirty patients are recruited for this study. Data analysis demonstrates a statistically significant association between our intra-operative CSF and LP sampling. Furthermore, our results also show for significant correlation between evidence of leptomeningeal disease on MRI findings versus intra-operative CSF positivity for tumour cells.

Conclusion

Although this is a retrospective study with a limited population, our data concurs with potential to avoid an additional procedure for the paediatric patient diagnosed with a malignant brain tumour.

Surgical Resection and Adjuvant Radiation Therapy in the Treatment of Skull Base Chordomas

OBJECTIVE

Chordomas are rare tumors of notochordal origin that are known to be locally aggressive and are often treated with surgical resection followed by adjuvant radiation therapy (RT). The accepted standard of treatment for chordomas of the mobile spine, which includes en-bloc resection with wide margins, cannot be easily applied to the chordomas of the skull base because of their proximity to critical neurovascular structures. We describe our experience with the role of surgery and adjuvant RT in the treatment of chordomas over 16 years.

METHODS

We performed a retrospective chart review on patients with diagnoses of clival chordoma between the years 2000 and 2015 at Northwestern Memorial Hospital. We reviewed presenting symptoms, tumor location and size, extent of resection, complications, recurrence, adjuvant treatment, and follow-up duration.

RESULTS

A total of 20 patients underwent 32 surgeries. Of the 20 initial surgeries, 80% underwent gross total resection, and 20% had subtotal resection. The mean follow-up time was 60.75 months. Mean tumor volume was 23.07 cm³. Most common presenting signs and symptoms were headaches (70%), cranial nerve palsies (45%), and diplopia (55%). Diplopia was defined as complaints of double vision without any objective evidence of a cranial nerve palsy. Median time to progression was 57 months, and median overall survival was 136 months. Initial tumor volume and the need for a second dose of RT either as sole or as adjuvant treatment of a recurrence had a statistically significant effect on progression-free survival (P = 0.009, 0.009). None of the factors studied had a statistically significant effect on overall survival.

CONCLUSIONS

The treatment of chordomas remain challenging and requires multimodal treatment strategies spanning different specialties. Initial tumor size and need for second dose of RT for recurrence appear to play a significant role in progression-free survival. Adjuvant RT after gross total resection may play a role in improved progression-free and overall survival in patients with clival chordomas.

Polymeric Micelle of A₃B-Type Lactosome as a Vehicle for Targeting Meningeal Dissemination

Polymeric micelle of the A₃B-type lactosome comprising (poly(sarcosine))₃-b-poly(l-lactic acid) was labeled with ¹¹¹In. The ¹¹¹In-labeled A₃B-type lactosome was administered to the model mice bearing meningeal dissemination and bone metastasis at mandible. With single-photon emission computed tomography (SPECT) imaging, the meningeal dissemination was identified successfully by ¹¹¹In-labeled A₃B-type lactosome, which was superior to ²⁰¹TlCl in regard of the imaging contrast. The ¹¹¹In-labeled A₃B-type lactosome was also potential in imaging selectively of bone metastasis at mandible, whilst a nonspecific imaging of the whole bone was obtained by the SPECT imaging using ^99mTc-HMDP. The polymeric micelle of the A₃B-type lactosome was therefore found to be effective as a vehicle of ¹¹¹In to be targeted to meningeal dissemination and bone metastasis.

Brain metastases: neuroimaging

Magnetic resonance imaging (MRI) is the cornerstone for evaluating patients with brain masses such as primary and metastatic tumors. Important challenges in effectively detecting and diagnosing brain metastases and in accurately characterizing their subsequent response to treatment remain. These difficulties include discriminating metastases from potential mimics such as primary brain tumors and infection, detecting small metastases, and differentiating treatment response from tumor recurrence and progression. Optimal patient management could be benefited by improved and well-validated prognostic and predictive imaging markers, as well as early response markers to identify successful treatment prior to changes in tumor size. To address these fundamental needs, newer MRI techniques including diffusion and perfusion imaging, MR spectroscopy, and positron emission tomography (PET) tracers beyond traditionally used 18-fluorodeoxyglucose are the subject of extensive ongoing investigations, with several promising avenues of added value already identified. These newer techniques provide a wealth of physiologic and metabolic information that may supplement standard MR evaluation, by providing the ability to monitor and characterize cellularity, angiogenesis, perfusion, pH, hypoxia, metabolite concentrations, and other critical features of malignancy. This chapter reviews standard and advanced imaging of brain metastases provided by computed tomography, MRI, and amino acid PET, focusing on potential biomarkers that can serve as problem-solving tools in the clinical management of patients with brain metastases.

Endoscopic Approach to Clival Chordomas: The Northwestern Experience

INTRODUCTION

Chordomas are rare primary bone tumors with a low-grade histology but an aggressive clinical behavior characterized by local invasion and recurrence. When occurring in the skull base, their treatment is limited by proximity to critical neurovascular structures. Open surgical approaches can carry high morbidity, making the development of alternative approaches desirable. We describe our experience with endoscopic endonasal approaches to clival chordomas over 13 years.

METHODS

We performed a retrospective chart review of patients diagnosed with clival chordomas and treated with an endoscopic endonasal approach between 2003 and 2015 at Northwestern Memorial Hospital. We reviewed presenting symptoms, tumor location and size, extent of resection, complications, recurrence, adjuvant treatment, retreatment, and follow-up duration.

RESULTS

A total of 23 charts were reviewed, with 17 included in our final review. Mean age was approximately 48 years. The most common presenting symptom was diplopia present in 70.6% of patients. Mean tumor volume was 20.2 cm³. Gross total resection was achieved in 52.9% of patients. With a mean follow-up period of 63.4 months, 5 patients had a recurrence. The most common complication was cerebrospinal fluid (CSF) leak, which was noted in 6 patients. Tumor volume was significantly higher in patients with CSF leak. No correlation between intradural extension and postoperative CSF leak was noted.

CONCLUSIONS

Clival chordoma are challenging entities to treat. The best outcomes are achieved with gross total resection followed by adjuvant radiotherapy treatment. We show that the endonasal endoscopic corridor is a viable alternative approach to these lesions.

Gadobutrol-enhanced magnetic resonance imaging of meningeal carcinomatosis: case report with emphasis on early diagnosis

Background

Timely diagnosis of meningeal carcinomatosis is often difficult even with the assistant of magnetic resonance imaging examination, cerebrospinal fluid analysis, or both. To the best of our knowledge, gadobutrol-enhanced MRI has not been reported in the diagnosis of meningeal carcinomatosis. Here we present two cases where meningeal carcinomatosis was identified on gadobutrol-enhanced magnetic resonance imaging.

Case presentation

We identified two cases of meningeal carcinomatosis who had been diagnosed with malignant tumors several years ago. Both patients presented with progressive headache and seizures. Gadopentetate dimeglumine-enhanced magnetic resonance imaging of the brain was performed and did not detect any abnormality of meninges. Lumbar puncture was performed repeatedly, but cerebrospinal fluid cytology showed no evidence of malignant cells. Finally the gadobutrol-enhanced magnetic resonance imaging detected the meningeal metastasis, and supported the diagnosis of meningeal carcinomatosis.

Conclusion

Gadobutrol provides higher lesion conspicuity and enhances lesion detection in meningeal metastasis compared with gadopentetate dimeglumine. Our observation is a cue to analyze the accuracy in the diagnosis of meningeal carcinomatosis, and presents a choice that may facilitate early diagnosis.