The Diagnostic Dilemma of Neurolymphomatosis

Neurosurgical Intervention for Nerve and Muscle Biopsies

(1) Background: Neurologic and musculoskeletal diseases represent a considerable portion of the underlying etiologies responsible for the widely prevalent symptoms of pain, weakness, numbness, and paresthesia. Because of the subjective and often nonspecific nature of these symptoms, different diagnostic modalities have been explored and utilized. (2) Methods: Literature review. (3) Results: Nerve and muscle biopsy remains the gold standard for diagnosing many of the responsible neurological and musculoskeletal conditions. However, the need for invasive tissue sampling is diminishing as more investigations explore alternative diagnostic modalities. Because of this, it is important to explore the current role of neurosurgical intervention for nerve and muscle biopsies and its current relevance in the diagnostic landscape of neurological and musculoskeletal disorders. With consideration of the role of nerve and muscle biopsy, it is also important to explore innovations and emerging techniques for conducting these procedures. This review explores the indications and emerging techniques for neurological intervention for nerve and muscle biopsies. (4) Conclusions: The role of neurosurgical intervention for nerve and muscle biopsy remains relevant in diagnosing many neurological and musculoskeletal disorders. Biopsy is especially relevant as a supportive point of evidence for diagnosis in atypical cases. Additionally, emerging techniques have been explored to guide diagnostics and biopsy, conduct less invasive biopsies, and reduce risks of worsening neurologic function and other symptoms secondary to biopsy.

Primary neurolymphomatosis diagnosed by spinal nerve root biopsy

Primary neurolymphomatosis is the direct infiltration of lymphomatous neoplastic cells into nerve roots and/or peripheral nerves. A 67-year-old man had a 24-month history of progressive and severe left lower limb neuropathic pain, ipsilateral ankle dorsiflexion weakness and gait disturbance. Gadolinium-enhanced MRI showed thickening and enhancement of the cauda equina, L5, S1 and S2 nerve roots. 18Fluorodeoxyglucose positron emission tomography showed concordant hypermetabolism. L5 nerve root biopsy confirmed diffuse large B-cell lymphoma. One cycle of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) chemotherapy resulted in remission, but this was not sustained. Primary neurolymphomatosis is rare and diagnostically challenging, and often the diagnosis is delayed. While biopsy is the gold standard for diagnosis, neuroimaging helps to characterise lesions and to determine the feasibility of biopsy.

Diffuse large B-cell lymphoma with contemporary involvement of central and peripheral nervous system: A case report and literature review

Introduction

Simultaneous involvement of the peripheral nervous system (PNS) and central nervous system (CNS) during the same period in diffuse large B-cell lymphoma (DLBCL) is rarely documented. In this particular case, the diagnosis of diffuse large B-cell lymphoma was pathologically confirmed, with invasion into the basal ganglia, diencephalon, and several peripheral nerves. The initial clinical manifestations were dyspnoea and hyperventilation.

Case presentation

The patient presented to the hospital with fatigue, dyspnoea, and limb pain for over 7 months, accompanied by progressive breathlessness and unconsciousness in the last 6 days. Initial treatment with glucocorticoids for Guillain-Barre syndrome (GBS) proved ineffective in controlling the severe shortness of breath and hyperventilation, necessitating the use of ventilator-assisted ventilation. 18-Fluorodeoxyglucose positron emission tomography/computed tomography (18FDG PET/CT) showed that the basal ganglia, brainstem, and multiple peripheral nerves were thickened and metabolically active. There were atypical cells in the cerebrospinal fluid; the pathology indicated invasive B-cell lymphoma, demonstrating a propensity toward diffuse large B-cell lymphoma (DLBCL). After receiving chemotherapy, the patient regained consciousness and was successfully weaned off ventilator assistance but died of severe pneumonia.

Discussion

The early clinical manifestations of DLBCL lack specificity, and multifocal DLBCL complicates the diagnostic process. When a single primary disease cannot explain multiple symptoms, the possibility of DLBCL should be considered, and nervous system invasion should be considered when nervous system symptoms are present. Once nervous system involvement occurs in DLBCL, whether the central or peripheral nervous system, it indicates a poor prognosis.

Primary peripheral nerve lymphoma: a case report and literature review

Neurolymphomatosis (NL) is an uncommon malignant lymphoma characterized by selective infiltration of the central and peripheral nervous system. In this case report, we present a patient diagnosed with diffuse large B-cell lymphoma who initially manifested with peripheral neuropathy, primarily characterized by weakness of the left lower limb. By exploring its clinical manifestations, ancillary tests, and reviewing the relevant literature, we aim to deepen our understanding, diagnosis, and treatment of this disease. A 48-year-old male patient presented to the Department of Neurology, Hematology, and Neurosurgery with complaint of left lower limb weakness that had persisted for over 11 months. Initial laboratory tests and cerebrospinal fluid analysis yielded negative results. Electromyography examination indicated damage to the left lumbar plexus and iliac plexus nerves raising suspicions of nerve root involvement. Enhanced MRI of the lumbosacral plexus nerves revealed thickening and enhanced signals in left nerve roots at T12-L1, L1-2, and L3-4 levels. Additionally, local thickening and enhancement of signals were observed in the left erector spine muscle, psoas major, and iliopsoas muscles compared to the contralateral side. PEC/CT imaging displayed multiple soft tissue density shadows in the left foraminal area at the T12-1 and L1-2 levels. Bone marrow examination excluded hematological disease. Subsequent biopsy of the left foraminal nerve root at T12-L1 and the vertebral muscle at L3 level confirmed a diagnosis of diffuse large B-cell malignant lymphoma, indicating PNSL due to the involvement of multiple nerve roots. Following diagnosis, the patient underwent chemotherapy, resulting in the alleviation of his symptoms. Diagnosing PNSL can be challenging due to the nonspecific clinical manifestations and often inconclusive laboratory test results. Misdiagnosis and delayed diagnosis are common pitfalls. Electromyography may reveal damage to the affected peripheral nerves, while MR imaging might show nerve root thickening, and PET/CT can demonstrate increased lesion uptake. However, the definitive diagnosis relies on a biopsy of the lesion. Treatment for PNSL typically involves chemotherapy.

Neurolymphomatosis as primary presentation of extra-nodal NK/T-cell lymphoma, nasal type

Neurolymphomatosis (NL) describes an infiltration of cranial and peripheral nerves by lymphoma cells, most frequently in non-Hodgkin B-cell lymphoma. This clinical entity is rare and poses a challenging diagnosis. We describe a case of a 64-year-old female patient with NL associated with extra-nodal NK/T-cell lymphoma (ENKTL), nasal type, presenting as a painful progressive mononeuropathy multiplex with an oral cavity lesion. ENKTL is usually associated with Epstein-Barr virus (EBV) infection and rarely affects the central and peripheral nervous system. Lumbar puncture, magnetic resonance imaging (MRI), nerve biopsy, and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) help to establish the diagnosis. Thereby, NL should be considered in the differential diagnosis of painful progressive multiple neuropathies, even in patients without previous history of cancer.

Pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis: a case report

Pronator syndrome is a median nerve entrapment neuropathy that can be difficult to diagnose due to its variable presentation and objective findings. Neurolymphomatosis is an uncommon disease in which malignant lymphocytes infiltrate central or peripheral nerve endoneurium and is often missed for prolonged periods prior to diagnosis. We present a rare case of pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis that was occult on initial MRI in spite of the presence of a median nerve mass discovered intra-operatively during neurolysis. This case demonstrates the value of ultrasound for the examination of peripheral nerve pathology and illustrates its utility as an adjunct to MRI, in part due to the ability to screen a large region.

Recurrence of diffuse large B-cell lymphoma in sciatic and tibial nerves: A case report

Infiltration of peripheral or cranial nerves with lymphatic cells is a rare condition that is known as neurolymphomatosis (NL). The involvement could be primary or secondary and mostly occurs in patients with a history of B-cell lymphoma. The most common peripheral nerve involved is the sciatic nerve. Patients may present with painful or painless mononeuropathy or polyneuropathy, and MRI is the perfect modality to evaluate the suspicious clinical findings that may demonstrate enlargement, thickening, and enhancement of the involved nerve or an enhancing mass lesion in the course of the nerve. Biopsy can be safely performed to confirm the diagnosis. Few articles have reported the cases of peripheral nerve involvement by lymphoma as well as MRI features of this diagnosis. In this article, we report a case of NL using MRI, ultrasound, and pathologic features and also present a brief review of relevant literature.

Cranial neurolymphomatosis and its oncologic counterparts: Case series on malignant cranial nerve neuropathies

Neurolymphomatosis occurs due to the infiltration of a nerve by malignant cells. Cranial neurolymphomatosis is a rare disease process associated with non-solid tumors (i.e., lymphoma, leukemia, etc.). Cranial neurolymphomatosis presents with single or multifocal neuropathy. Primary cranial neurolymphomatosis is defined as the initial presenting symptom leading to a new diagnosis of cancer. Secondary cranial neurolymphomatosis is defined as cancer progression with spread to a cranial nerve. While cranial neurolymphomatosis is a recognized cause of cranial nerve neuropathies, a myriad of other malignancies can also lead to similar clinical manifestations. This case series elucidates not only the classical presentations associated with cranial neurolymphomatosis but also introduces other oncologic entities that may compromise cranial nerve functions. A descriptive case series is presented on six patients with malignancy-related cranial neuropathy who came to a tertiary-care center from 2018 to 2022. 5/6 (83.3%) of patients presented with primary cranial neuropathy. Diffuse large B-cell lymphoma was the most prevalent malignancy observed in 3/6 (50.0%) cases. Other malignancies observed include non-Hodgkin lymphoma, monoclonal B-cell lymphocytosis, and peripheral T-cell lymphoma. The most affected cranial nerve was the trigeminal nerve in 4/6 (66.6%) individuals. Multiple cranial neuropathies were seen in 2/6 (33.3%) of patients. The most common neuroradiographic finding was a lesion to Meckel's cave. Other cranial nerves affected include the optic, facial, and vestibulocochlear nerves. Diagnostic modalities utilized included magnetic resonance imaging and 18F-fluoro-2-D-glucose positron emission tomography-computerized tomography. Cerebrospinal fluid analysis for flow cytometry may also have diagnostic value in patients with increased disease burden. Treatment was guided according to individual malignancy and 2/6 (33.3%) patients achieved complete remission, 2/6 (33.3%) died within 1 year, and 1/6 (16.6%) were referred to hospice. Cranial neuropathy may be the first symptom of a neoplastic process; thus, prompt recognition and treatment may improve morbidity and mortality.

Neurolymphomatosis as an Initial Presentation of Non Hodgkins Lymphoma: A Case Report

Neurolymphomatosis (NL) is a rare clinical disease where neoplastic cells invade the cranial nerves, roots, plexus, or other peripheral nerves in patients with hematologic malignancy mainly Non-Hodgkins Lymphoma(NHL). Primary NL occurs as the first manifestation of a hematologic malignancy. We report a 68-year male who presented to us with low backache and burning paraesthesia in the back of both lower limbs followed by a left foot drop. The clinical and electrophysiological examination was suggestive of bilateral lumbosacral radiculopathy involving L2-S1 roots. Plain MRI of the lumbosacral spine was normal. F18FDG PET CT Scan revealed increased uptake in both L5 and left L3 roots. Contrast-enhanced MRI of the lumbosacral spine showed marked fusiform thickening and enhancement of both L5 and left L3 roots CT-guided Biopsy from left L5 root, lymph node, and bone marrow was suggestive of large B cell lymphoma-germinal center cell type. The diagnosis was neurolymphomatosis secondary to NHL.

B-Cell Lymphoma Presenting With Seventh Cranial Nerve Palsy and Mononeuritis Multiplex: A Case Report and Comprehensive Literature Review

Diagnosing B-cell lymphoma-associated mononeuritis multiplex is challenging due to its rarity and the potential co-existence of other causes of mononeuritis multiplex. Here, we report a case of a 74-year-old male who initially presented with left cranial neuropathies followed by right-sided extremity weakness with hyporeflexia, right facial involvement, and subsequently asymmetric weakness and multifocal muscle wasting. Minor improvements were observed with multiple rounds of steroid treatment. The diffuse large B-cell lymphoma diagnosis was eventually established six months later upon a repeat mediastinal lymph node biopsy and cerebrospinal fluid cytology. A nerve biopsy demonstrated severe axonal neuropathy with loss of axons in all fascicles without evidence of vasculitis. A muscle biopsy showed atrophy in both type 1 and type 2 fibers. A presentation of mononeuritis multiplex warrants concern for B-cell lymphoma, mainly when other mechanisms of peripheral neuropathy are less likely.

COVID-19 associated Bell's Palsy and lumbosacral neurolymphomatosis in a patient with B-cell lymphoma-Case Report

This is a case of acute onset unilateral Bell's Palsy during COVID-19 illness, coinciding with development of progressive leg pain, weakness, and sensation change. The patient was ultimately found to have a large B-cell lymphoma mass invading the sciatic nerve, lumbosacral plexus and the spinal canal with compression of cauda equina consistent with neurolymphomatosis. Although COVID-19 infection has been associated with Bell's palsy, Bell's palsy has also been reported with lymphoid malignancy. We review current literature on the association of Bell's palsy with COVID-19 infection and lymphoid malignancy, as well as review the diagnostic challenges of neurolymphomatosis. Providers should be aware of the possible association of Bell's palsy as harbinger of lymphoid malignancy.

Navigating treatment options for sacral spine lymphoma: A medical journey

INTRODUCTION AND IMPORTANCE

Early clinical presentations of spinal processes involving the epidural space are often vague and can mimic other spinal nerve impingements. Patients with NHLs frequently experience neurological problems due to metastatic spinal cord compression (MSCC).

CASE PRESENTATION

In this case report, we present a 66-year-old female patient who was diagnosed with diffuse large B-cell lymphoma (DLCBL) of the sacral spine after a recurrence of cauda equine syndrome. The patient initially presented with back discomfort, radicular pain, and muscle weakness, which progressed to weakness in the lower extremities and bladder dysfunction over a few weeks. The patient was treated by surgical decompression and the biopsy result revealed a diagnosis of DLBCL. Further workup proved the tumor is primary and the patient as treated with radio- and chemotherapy.

CLINICAL DISCUSSION

The varied distribution of symptoms based on the spinal level of the lesion makes early clinical diagnosis of spinal NHL challenging. In this case, the patient's initial symptoms closely resembled intervertebral disc herniation or other spinal nerve impingements, which delayed the diagnosis of NHL. The abrupt onset and progression of neurological symptoms in the lower extremities and bladder dysfunction raised the suspicion of MSCC.

CONCLUSION

NHLs can present as metastatic spinal cord compression, which can cause neurological problems. Early clinical diagnosis of spinal NHLs is challenging due to the vague and varied presentations. A high index of suspicion for MSCC should be maintained in patients with NHLs who present with neurological symptoms.

Neurolymphomatosis: involvement of peripheral nervous system revealing hematologic malignancy, a report of nine cases

BACKGROUND AND AIM

Neurolymphomatosis is defined as an infiltration of the peripheral nervous system (PNS) by malignant lymphoma cells. It is a rare entity and diagnosis is complicated especially when PNS involvement is the initial and leading symptom. To improve knowledge of the disorder and shorten the time to diagnosis, we report a series of nine patients without a history of hematologic malignancy, who were diagnosed with neurolymphomatosis after evaluation and workup of peripheral neuropathy.

METHODS

The patients were included from the Department of Clinical Neurophysiology at Pitié Salpêtrière and Nancy Hospitals over a period of 15 years. Diagnosis of neurolymphomatosis was confirmed by histopathologic examination for each patient. We characterized their clinical, electrophysiological, biological, imaging, and histopathologic features.

RESULTS

The neuropathy was characterized by pain (78%), proximal involvement (44%) or of all four limbs (67%), asymmetrical or with multifocal distribution (78%), abundant fibrillation (78%), a tendency to worsen rapidly, and significant associated weight loss (67%). Neurolymphomatosis was diagnosed principally on nerve biopsy (89%) identifying infiltration of lymphoid cells, atypical cells (78%), a monoclonal population (78%), and supported by fluorodeoxyglucose-positron emission tomography, spine or plexus MRI, cerebrospinal fluid analysis, and blood lymphocyte immunophenotyping. Six patients had systemic disease and three impairment limited to the PNS. In the latter case, progression could be unpredictable and may be diffuse and explosive, sometimes occurring years after a seemingly indolent course.

INTERPRETATION

This study provides better knowledge and understanding of neurolymphomatosis when neuropathy is the initial presentation.

Neurolymphomatosis in Recrudescent Diffuse Large B-cell Lymphoma

Neurolymphomatosis is an uncommon manifestation of lymphoma, often presenting with painful polyneuropathy or polyradiculopathy and concomitant distal extremity weakness. Differentiation from other etiologies resulting in similar neuropathic symptoms such as compressive or inflammatory pathologies can be difficult and often results in delayed diagnosis. Here we describe a case of neurolymphomatosis affecting a 64-year-old man with a history of diffuse large B-cell lymphoma (DLBCL) in remission presenting with a right-sided foot drop following a gunshot wound. MRI at that time demonstrated thickening and enhancement of the cauda equina nerve roots. Over the course of the subsequent eight months, he developed left lower extremity sensory symptoms, left-sided foot drop and signs of upper motor neuron involvement, including left facial weakness, dysphonia, and dysphagia. ¹⁸F-FDG PET/CT revealed intensely avid left lumbosacral nerve roots, bilateral lower extremity and left upper extremity neurovascular bundles. Left sural nerve biopsies showed infiltration of DLBCL and confirmed neurolymphomatosis. We highlight the role of ¹⁸F-FDG PET/CT, with histological verification, for the diagnosis of an extended course of neurolymphomatosis occurring in the absence of typical painful neuropathy but with cranial and peripheral neuropathies.

A Case Series of Neurolymphomatosis: Role of Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scan Reiterated

Neurolymphomatosis is rarely encountered in high-grade lymphomas. In this case series, we retrospectively analyzed six neurolymphomatosis cases to look for possible risk factors, common and uncommon presentations, and the lessons learned. Neuropathic pain was the most common symptom with mono or polyradiculopathy in this series. However, all lymphomatous infiltrated nerves diagnosed on fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) were not symptomatic. The lumbar, brachial plexus, and trigeminal nerve were the most common sites and were depicted well on FDG PET/CT. Magnetic resonance imaging (MRI) of the brain better delineates cranial nerves and meningeal involvement. Cerebrospinal fluid flow cytometry was normal until meninges were involved. FDG PET/CT incrementally evaluated extra-neural disease sites, thus helping in deciding biopsy sites and further management. We concluded that a whole-body FDG PET/CT including limbs with MRI brain was the appropriate investigation for evaluating suspected neurolymphomatosis in advanced-stage diffuse large B-cell lymphoma.

Neurolymphomatosis with Spinal Nerve Root Involvement Demonstrated on 18F-FDG PET/CT

A 56 years old woman with a diagnosis of diffuse large B-cell lymphoma had dyspnea, weakness in the left upper extremity and vocal cord paralysis after chemotherapy. She underwent cervical, thoracal and lumbosacral magnetic resonance imaging (MRI) however findings on MRI could not entirely explain the symptoms of the patient. Therefore, the patient underwent ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography and the scan revealed focal symmetrical ¹⁸F-FDG uptake on the cervical, thoracal and lumbal spinal nerve roots. Considering the symptoms of the patient and cerebrospinal fluid cytology findings, hypermetabolic spinal nerve roots were interpreted as lymphoma involvement.

Neurolymphomatosis in follicular lymphoma: an autopsy case report

Neurolymphomatosis is a neurological manifestation of lymphoma that involves the cranial or spinal peripheral nerves, nerve roots, and plexus with direct invasion of neoplastic cells. Neurolymphomatosis is rare among patients with low-grade lymphoma. We report an autopsied case of neurolymphomatosis that arose from follicular lymphoma. A 49-year-old woman who presented with pain of her neck and shoulder and numbness of her chin. Computed tomography revealed enlarged lymph nodes in her whole body, and biopsy from the axillary lymph node revealed grade 2 follicular lymphoma. Although the patient underwent chemotherapy, she gradually developed muscle weakness in the upper limbs and sensory disturbances of the trunk and limbs. ¹⁸ F-fluorodeoxyglucose positron emission tomography (FDG-PET) revealed increased tracer uptake of the cervical nerve roots. Repeated FDG-PET after additional therapy revealed progression of disease within the nerve roots and brachial plexus, whereas gadolinium-contrast magnetic resonance imaging (MRI) showed weak enhancement of the cervical nerve roots without formation of mass lesions. She died after a total disease duration of 12 months. Postmortem observations revealed invasion of lymphoma cells into the cervical nerve roots, dorsal root ganglia, and subarachnoid spaces of the spinal cord. Neurolymphomatosis was prominent at the segments of C6-Th2. Combined loss of axons and myelin sheaths was observed in the cervical nerve roots and posterior columns. Lymphoma cells also invaded the cranial nerves. The subarachnoid and perivascular spaces of the brain demonstrated focal invasion of the lymphoma. Mass lesions were not observed in the central nervous system. The lymphoma cells did not show histological transformation to higher grades, and the density of the centroblasts remained at grade 2. Our report clarifies that low-grade follicular lymphoma can manifest as neurolymphomatosis and central nervous system invasion in the absence of transformation toward higher histological grades. FDG-PET may be more sensitive to non-mass-forming lesions, including neurolymphomatosis, than gadolinium-contrast MRI.

High-Grade B-Cell Lymphoma of the Sciatic Nerve That Mimicked a Schwannoma: A Case Report

CASE

A 41-year-old woman with a history of high-grade B-cell lymphoma status-post chemotherapy was evaluated for a painful left posterior thigh mass and significant weakness with sensory changes. Imaging revealed a benign-appearing mass consistent with schwannoma; however, intraoperative frozen section suggested high-grade B-cell lymphoma. Subsequent restaging studies revealed metastatic disease.

CONCLUSION

A history of lymphoma warrants careful investigation of a posterior thigh mass, despite imaging findings consistent with nerve sheath tumor. Surgical removal of lymphomas of the nerve often proves futile, so these lesions are usually managed with medical treatment or radiation.

Mononeuritis multiplex as a rare and severe neurological complication of immune checkpoint inhibitors: a case report

BACKGROUND

Mononeuritis multiplex is a rare autoimmune peripheral neuropathy that typically presents in the context of vasculitis, diabetes, infection, or as a paraneoplastic syndrome. Adverse immune-related neurological conditions have been increasingly reported with the use of immune checkpoint inhibitors against cytotoxic T-lymphocyte antigen-4 and/or the programmed cell death protein 1/programmed death ligand-1 axis. Mononeuritis multiplex has only been reported twice from treatment of cancers with immunotherapy.

CASE PRESENTATION

Here we report a case of mononeuritis multiplex as a complication of immune checkpoint inhibitor therapy for melanoma. An 80-year-old non-Hispanic white female with recurrent melanoma was treated with combination ipilimumab and nivolumab and subsequently presented with progressive leg weakness, back pain, and difficulty ambulating. The diagnosis of mononeuritis multiplex was made, which was resistant to steroid pulses, chronic steroids, intravenous immunoglobulin, and rituximab. She developed progressive neurologic dysfunction and elected for hospice care. We found only two other cases reported in the literature.

CONCLUSIONS

Increased awareness, prompt recognition, and aggressive treatments are likely the best opportunity for improved outcomes in this severe side effect.

Primary Extranodal NK/T-Cell Lymphoma Presenting as Neurolymphomatosis Involving Multiple Cranial Nerves: A Case Report

Neurolymphomatosis (NL) is a rare condition caused by the lymphomatous or leukemic infiltration of nerves and manifests as neuropathy. Most often, NL is associated with B-lineage non-Hodgkin lymphoma (NHL) and only infrequently occurs in conjunction with T- or NK-lineage NHL. Extranodal NK/T-cell lymphoma (ENKTL)-associated NL is exceedingly unusual, with only 9 cases described in the English language literature, in addition to our case. Diagnosis of NL is challenging, as the entity can mimic neuropathies of more common etiologies, and an adequate biopsy may be difficult to obtain. Timely diagnosis demands a high index of suspicion, especially for patients without a history of hematologic malignancy. We expand upon a unique case of NL exclusively involving cranial nerves and cauda equina nerve roots, as the initial manifestation of ENKTL, and contextualize our findings within the framework of previously reported NK/T-lineage NL cases.

Nerve biopsy: Current indications and decision tools

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Clinical manifestations of, diagnostic approach to, and treatment of neurolymphomatosis in the rituximab era

Neurolymphomatosis (NL) is a rare manifestation of lymphoma, with limited evidence for optimal management. The largest patient series, 50 cases of lymphoma and leukemia, was published in 2010 with limited rituximab exposure. This study aims to evaluate the clinical presentation, diagnostic testing, and outcomes of NL in the rituximab era. Forty biopsy-proven cases of NL, in association with non-Hodgkin lymphoma (NHL), at the Mayo Clinic were retrospectively evaluated. B-cell NHL was associated with 97% of NL cases, of which diffuse large B-cell lymphoma (DLBCL) was the most common (68%). Primary NL, defined as neural involvement present at the time of diagnosis of lymphoma, was noted in 52% cases. Seventy percent of patients presented with sensorimotor weakness and neuropathic pain. Magnetic resonance imaging (MRI) was positive in 100% patients. Overall survival (OS) was significantly better for primary NL and NL associated with indolent lymphomas. Relapses were seen in 60% (24/40) of patients; 75% involved the peripheral or central nervous system at relapse. The use of rituximab in the frontline setting significantly impacted progression-free survival (PFS). Transplant consolidation was noted to be associated with improved OS. This study adds to the available literature on NL in the rituximab era. The overall outcomes have improved in recent years. In our experience, MRI and positron emission tomography/computed tomography may be required for accurate assessment of the extent of disease involvement and identification of an optimal biopsy site. The use of rituximab was associated with improvement in PFS, and autologous stem cell transplant was associated with OS.

Sciatic nerve neurolymphomatosis as the initial presentation of primary diffuse large B-cell lymphoma: a rare cause of leg weakness

Neurolymphomatosis (NL) is defined as the involvement of the peripheral nervous system in lymphocytic invasion. It is a very rare form of lymphoma that may occur as an initial presentation or recurrence. It affects various peripheral nervous structures and can therefore mimic disc-related nerve root pathology or compressive mononeuropathy. NL often occurs in malignant B-cell non-Hodgkin lymphomas. Notwithstanding its aggressiveness or intractability, NL should be discriminated from other neurologic complications of lymphoma. Herein, we present a case of primary NL as the initial presentation of diffuse large B-cell lymphoma (DLBCL) of the sciatic nerve. The patient presented with weakness and pain in his left leg but had no obvious lesion explaining the neurologic deficit on initial lumbosacral and knee magnetic resonance imaging (MRI). NL of the left sciatic nerve at the greater sciatic foramen was diagnosed based on subsequent hip MRI, electrodiagnostic test, positron emission tomography/computed tomography, and nerve biopsy findings. Leg weakness slightly improved after chemotherapy and radiotherapy. We report a case wherein NL, a rare cause of leg weakness, manifested as the initial presentation of primary DLBCL involving the sciatic nerve at the greater sciatic foramen.

Isolated primary neurolymphomatosis with cranial multineuritis: a case presentation

BACKGROUND

Isolated primary neurolymphomatosis (NL) of cranial multineuritis is a very rare condition that refers to the lymphomatous invasion of cranial nerves only. There are sparse cases of isolated cranial nerves NL reported worldwide.

CASE PRESENTATION

We present magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) findings of a 63-year-old female patient suffering from isolated neurolymphomatosis of cranial multineuritis with a wide constellation of syndromes including binocular diplopia, left facial paralysis and pain, syncope episodes, and progressive dysphagia. A contrasted MRI brain showed multiple cranial nerves enhancement. Extensive workup for infectious, autoimmune, neoplastic, paraneoplastic, or inflammatory etiologies had been unrevealing except CSF cytology revealed large atypical monotypic B cells that were suspicious for non-Hodgkin lymphoma on the third large volume tap. The decision of biopsy was deferred after the risks and benefits discussion. Following the four cycles of empiric methotrexate-based induction chemotherapy, the patient's symptoms resolved, and a complete radiographic response was achieved without whole-brain radiation or autologous hematopoietic cell transplantation. In the latest follow-up, she is independent with her daily activities and remains in clinical and radiographic remission more than 3 years since initial chemotherapy.

CONCLUSION

Isolated NL of cranial nerves can present diagnostic and management pitfalls for the neurologist, neurosurgeons, and oncologists. Since current diagnostic modalities have modest sensitivity and a pathological diagnosis is often difficult, empiric treatment once other possibilities are ruled out can carry a good prognosis.

Neurolymphomatosis - Rare presentation in non-Hodgkin's lymphoma: The role of 18F-fluorodeoxyglucose positron-emission tomography and computerized tomography imaging

Neurolymphomatosis (NLS) is infiltration of lymphoma cells into the peripheral or cranial nervous system and is a rare manifestation of non-Hodgkin lymphoma (NHL). Nerve biopsy is considered as the gold standard for diagnosis but not a preferred choice, and magnetic resonance imaging has lower reported sensitivity. ¹⁸F-Fluorodeoxyglucose (¹⁸FDG) positron-emission tomography and computerized tomography (PET/CT) has a higher sensitivity for diagnosing and assessing the neurological and nonneurological metabolic tumor volume and response evaluation to therapy. We present the case of a lady, known to have NHL in remission. She presented with a short history of severe pain and weakness of the right lower limb. Baseline and interim ¹⁸FDG PET/CT played a crucial role in diagnosing and assessing the extent of NLS and nonneurological disease burden and also in evaluation of response to treatment.

Primary Central Nervous System Lymphoma With Diffuse Neurolymphomatosis Involving Multiple Cranial and Spinal Nerve Roots

Primary central nervous system lymphoma is an extranodal lymphoma originating in the brain, spinal cord, and leptomeninges, which rarely spreads outside the nervous system. Neurolymphomatosis is the term used to describe lymphomatous involvement of the cranial nerves (except optic nerve) and peripheral nerve roots or plexus. We report a case of a 23-year-old man presented with progressive weakness of all 4 limbs. F-FDG PET/CT revealed FDG-avid thickening along the multiple cranial nerve roots, spinal nerve roots, and brain parenchymal lesion. Core biopsy from the peripheral nerve root demonstrated the lymphomatous involvement.

Peripheral nerve neurolymphomatosis: Clinical features, treatment, and outcomes

This series characterises nine patients with neurohistopathologically proven peripheral nerve neurolymphomatosis. A search of the hospital neuropathology database from 2002 to 2019 identified biopsy proven cases. Clinical data, investigation modalities, treatments, and outcomes were collated. Median age at neuropathy onset was 47 y, the neuropathy commonly as the initial lymphoma disease manifestation. Most (8/9) presented with painful asymmetrical sensory disturbance, with additional cranial nerve involvement in three. Neurophysiology typically demonstrated multiple axonal mononeuropathies. Cerebrospinal fluid protein was often raised (6/8). Magnetic resonance imaging suggested peripheral nerve infiltration in 6/9 and positron emission tomography CT in 4/9. Bone marrow biopsy was abnormal in 6/8. Treatment involved systemic or intrathecal chemotherapy and radiotherapy. Median survival was 23 mo. Neurolymphomatosis is a rare but important cause of neuropathy, particularly in those lacking systemic evidence of lymphoma as correct aggressive treatment can prolong survival. Nerve biopsy is essential to classify lymphoma type and rule out alternatives.

Disseminated lymphoblastic lymphoma revealed by an isolated third cranial nerve palsy

Dysfunction of the third cranial nerve can be provoked by a number of different conditions. An isolated cranial neuropathy as a first clinical sign of a non-Hodgkin lymphoma is very infrequent. We represent here an atypical case of lymphoblastic lymphoma revealed by an isolated third cranial nerve palsy. The patient was managed by alternating cycles of cyclophosphamide, vincristine, and prednisone. She made a full recovery with a complete resolution of the symptomatology.

B-cell peripheral neurolymphomatosis: MRI and 18F-FDG PET/CT imaging characteristics

OBJECTIVE

To examine the MRI and ¹⁸F-FDG PET/CT imaging characteristics of peripheral neurolymphomatosis.

MATERIALS AND METHODS

All institutional cases of neurolymphomatosis with an MRI or ¹⁸F-FDG PET/CT from 2000 to 2017 were retrospectively reviewed. Included cases were biopsy-proven neurolymphomatosis or lymphoma patients with clinical and imaging evidence of neurolymphomatosis that resolved after chemotherapy. Multiple imaging parameters and clinical characteristics were recorded.

RESULTS

There were 27 cases of B-cell neurolymphomatosis in 25 patients (18 M, 7 F; mean age 64.6 ± 10.0 years). Of the total cases, 85% (23/27) were biopsy-proven. Most were diagnosed after disease progression or recurrence (20/27, 74%), and presented with isolated nerve involvement (18/27, 67%). Bone marrow biopsy (17/19, 89%) and CSF cytology (16/23, 70%) were usually negative. On ¹⁸F-FDG PET/CT, neurolymphomatosis presented as a linear or fusiform (23/26, 88%), FDG-avid (average SUVmax: 7.1 ± 4.5, range, 1.5-17.0) mass, and on MRI as a T2-weighted hyperintense (21/22, 95%), enhancing (21/22, 95%), linear or fusiform mass (19/22, 86%), with associated muscle denervation (14/22, 64%). FDG avidity was significantly higher in patients with muscular denervation on MRI (mean SUVmax 8.2 ± 4.6 vs. 4.3 ± 2.3, p = 0.04).

CONCLUSIONS

B-cell neurolymphomatosis most commonly manifests as T2-weighted hyperintense, enhancing linear or fusiform neural enlargement associated with muscular denervation on MRI, with intense FDG activity on PET/CT. It is most often an isolated site of disease, presenting after progression or recurrence. A familiarity with the imaging appearance of neurolymphomatosis can help refine the differential diagnosis, direct biopsy, and aid in accurate diagnosis.

Feline lymphoma in the nervous system: pathological, immunohistochemical, and etiological aspects in 16 cats

ABSTRACT: The pathological, immunohistochemical (IHC), and etiological features of lymphoma involving the nervous system (NS) in cats were analyzed through a retrospective study (2004-2017) in Rio Grande do Sul State, Brazil. The NS involvement was observed in 16 (12.2%) of 125 felines with lymphoma. Young cats were mainly affected, with a median of 24 months old. Most cases were secondary central NS lymphoma, whereas in three cats, the NS involvement was primary. IHC revealed 14 (87.5%) FeLV-positive, six FIV-positive, and one FeLV/FIV-negative cats. Distribution of feline lymphoma in the NS was 8/16 in the spinal cord, 7/16 in the brain, and 1/16 in the paravertebral nerves and ganglia (neurolymphomatosis). The lymphoma pattern in the spinal cord was exclusively extradural, often focal (6/8), and located in the lumbar (3/6), sacral (1/6), thoracic (1/6), and cervical segments (1/6). Brain neuroanatomical patterns were: leptomeningeal lymphomatosis (4/7), lymphomatous choroiditis (2/7), and intradural lymphoma (1/7). The feline with primary neurolymphomatosis presented a marked thickening of paravertebral nerves and ganglia from the sacral region. B-cell lymphoma (75%) was often diagnosed, and diffuse large B-cell lymphoma (DLBCL) (11/16) was the main subtype. T-cell lymphoma (25%) was less commonly observed and was classified as peripheral T-cell lymphoma (PTCL) (3/16) and T-cell lymphoblastic lymphoma (T-LBL) (1/16).

Limited efficacy of high-dose methotrexate in patients with neurolymphomatosis

Neurolymphomatosis (NL) is a rare manifestation of non-Hodgkin lymphoma, in which malignant cells infiltrate the peripheral nerves. Most patients are treated with high-dose methotrexate (HD-MTX)-based systemic chemotherapy regimens similar to patients with central nervous system lymphoma. However, because NL is rare, the efficacy of HD-MTX is largely unknown. We reviewed medical records of patients diagnosed with NL over the past 10 years and identified 18 patients. The underlying hematological malignancy was diffuse large B-cell lymphoma (DLBCL) in 10 patients (55.6%), intravascular large B-cell lymphoma in six (33.3%), and other types in two patients. Ten patients were treated with HD-MTX-based systemic chemotherapy; the response rates with and without HD-MTX-based chemotherapy were 100% (n = 10) and 85.7% (n = 6), respectively (P = 0.41). The median progression-free and overall survival rates of patients with versus without HD-MTX treatment were 6.4 vs. 8.5 months (P = 0.97) and 13.5 vs. 8.5 months (P = 0.63), respectively. Despite the initial favorable responses, rapid disease recurrence was observed in most patients administered HD-MTX-based chemotherapy. Our observations suggest that HD-MTX-based chemotherapy may have insufficient efficacy against NL, and that other therapeutic approaches are required to improve the outcomes of patients with this rare disease.

Isolated Third Cranial Nerve Palsy Leading to the Diagnosis of Disseminated Burkitt Lymphoma: A Case Report and Literature Review

INTRODUCTION

Dysfunction of the third cranial nerve can result from lesions anywhere along its course between the midbrain and the orbit. Lymphoma is a rare cause of isolated oculomotor nerve palsy (OMP), with only 19 cases reported in the literature. We describe a case of an isolated OMP leading to the diagnosis of disseminated Burkitt lymphoma (BL).

CASE REPORT

A 37-year-old man presented with acute onset diplopia and right ptosis and was found to have a right pupillary sparing OMP. The diagnostic workout was unremarkable, including contrast-enhanced brain and orbital magnetic resonance imaging, MR angiography, exhaustive laboratory tests, and cerebrospinal fluid analysis. After a course of high-dose intravenous steroid therapy, the patient recovered almost completely. Three weeks after the discharge, he developed lumbar radicular pain and lower limbs weakness followed by the relapse of the right OMP. A second lumbar puncture revealed the presence of "small monomorphic lymphocytes," consistent with leptomeningeal lymphomatosis. A whole-body positron emission tomography scan disclosed a mediastinal mass, whose histopathologic "starry sky" appearance was pathognomonic for BL.

CONCLUSIONS

Reviewing the literature, we were able to find only 3 cases of OMP as the presenting manifestation of BL, all occurring in patients with predisposing HIV infection.Our case of isolated OMP highlights some "red flags" for a lymphomatous etiology, including young age, a progressive course, a response to high-dose steroid therapy, and relapse upon steroid discontinuation; these cases require a comprehensive evaluation, including repeated cytological cerebrospinal fluid analysis and sensitive imaging techniques to detect a possible primary lesion.

Neurolymphomatosis in non-Hodgkin lymphoma with cranial multineuritis: A case report

RATIONALE

Neurolymphomatosis (NL) is a rare syndrome of lymphoma and leukemic infiltration of cranial or peripheral nerves.

PATIENT CONCERNS

We report a case of non-Hodgkin Lymphoma (NHL) in a 24-year-old man presented with difficulty in swallowing, hypersalivation, hoarseness, ptosis, facial paralysis, and facial hypoesthesia associated with NL.

DIAGNOSIS

NL was diagnosed based upon cranial magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) examination.

INTERVENTIONS

The patient was treated with intrathecal methotreaxate (12.5 mg) and cytosine arabinoside (70 mg), systemic high-dose methotrexate therapy, and cranial radiotherapy.

OUTCOME

Due to the deterioration of general condition of the patient, he was admitted to intensive care unit, but died 22 days after the onset of symptoms in spite of aggressive treatment.

LESSONS

In this case, we present a patient with T cell lymphoma and multineuritis of NL diagnosed by MRI and as far as we know, this is the first reported case in which so many cranial nerves (3, 5, 7, 8, 9, and 10 th) were involved. Briefly, in a patient with hematologic malignancy and neurological complaints, NL should be considered. Early and effective use of imaging modalities such as positron emission tomography (PET-CT), MRI, and aggressive therapies are important for prolonged survival.

Partial Conduction Block as an Early Nerve Conduction Finding in Neurolymphomatosis

BACKGROUND AND PURPOSE

Neurolymphomatosis is a rare manifestation of hematological malignancy and is characterized by direct infiltration of the peripheral nervous system. The objective of this study was to identify the clinical and electrophysiological features of neurolymphomatosis.

METHODS

We retrospectively analyzed the medical records of 13 patients with neurolymphomatosis. Seven (54%) of the patients were men, and the median age at symptom onset was 60.0 years.

RESULTS

The most common type of underlying malignancy was diffuse large B-cell lymphoma (69%). Twelve patients had painful asymmetric neuropathies. The median survival time after diagnosis was 7 months, and 12 patients died during the study period. Thirty-eight motor nerve conduction studies (NCSs) were performed in the affected nerves. Ten and 28 motor nerves were classified into the conduction-block and simple-axon-degeneration groups, respectively. The median time interval between symptom onset and the NCS was significantly shorter in the conduction-block group than in the simple-axon-degeneration group (p=0.032). However, no significant differences in the motor nerve conduction velocities, terminal latencies, and distal compound muscle action potential amplitudes were identified between the conduction-block and simple-axon-degeneration groups. The conduction-block group showed excessive temporal dispersion in only five of the ten NCSs (50%). Follow-up NCSs revealed that partial conduction blocks had changed into axonal degeneration patterns.

CONCLUSIONS

This is the first study to analyze the electrophysiological features of patients with neurolymphomatosis. Our findings showed that a partial conduction block is not rare and is an early nerve conduction abnormality in neurolymphomatosis.

FDG PET-CT evaluation in neurolymphomatosis: imaging characteristics and clinical outcomes

Neurolymphomatosis (NL) often represents unidentified non-Hodgkin lymphoma relapses. Considering its severity, early detection and treatment are crucial. We outline one hospital's ¹⁸F-FDG-PET-CT imaging findings of NL, along with the patients' clinical characteristics. Clinical records and imaging findings of 19 NL patients, PET-CT diagnosed, were retrospectively reviewed. Patient data, FDG-PET-CT findings and the presence of coexisting diseases, especially CNS involvement, were documented. Available MRI and clinical data verified the findings. All cases had increased linear FDG uptake along anatomic nerve sites. CTs showed varying degrees of corresponding soft-tissue-thickening. Clinical correlations also contributed to the diagnosis. In 4/19 patients, lymphoma presented with NL, in 15/19 it appeared with disease recurrence/progression. In 9/19, clinical symptoms suggested neural involvement while 10/19 had nonspecific symptoms. Eleven died of lymphoma within 0.9 years of diagnosis despite directed-therapy. Eight, however, survived up to 7.82 years post-diagnosis. Whole-body FDG-PET-CT can assist in early NL diagnosis, possibly enhancing survival.