The paraneurium and the tumefactive appearance of peripheral nerve neurolymphomatosis: illustrative case

BACKGROUND

Peripheral neurolymphomatosis (NL) is an often-misdiagnosed condition characterized by lymphomatous infiltration within the peripheral nerves. Its rarity and complexity frequently result in delayed diagnosis and suboptimal patient outcomes. This study aims to elucidate the role of the paraneurium (circumneurium) in NL, emphasizing its diagnostic and therapeutic significance.

OBSERVATIONS

A 72-year-old man presented with lesions on his right lower eyelid. Initial diagnostics were inconclusive until an excisional biopsy confirmed extranodal marginal zone lymphoma. Following a complete metabolic response to rituximab treatment, the patient relapsed 14 months later with progressive lymphoma and bilateral sciatic nerve involvement, as confirmed by positron emission tomography-computed tomography and magnetic resonance imaging.

LESSONS

This paper underscores the critical role of the paraneurium in NL, enhancing understanding of its pathophysiology. Integrating advanced imaging techniques have proved essential in accurately identifying neurolymphomatous involvement within the paraneurium. This study paves the way for more effective management strategies in NL and similar conditions, focusing on improving patient care and outcomes.

Primary adrenal lymphoma presenting as neurolymphomatosis: A case report

RATIONALE

Primary adrenal lymphoma (PAL) is a very rare and highly aggressive disease. Neurolymphomatosis (NL) is a rare manifestation of lymphoma characterized by the infiltration of lymphoma cells into peripheral nerves, resulting in neurological symptoms. To date, there have been very few reported cases of PAL with NL. By reviewing the entire treatment process of the patient, we aim to enhance recognition of PAL complicated with NL and guide clinicians to pay attention to the diagnosis of such diseases. Early recognition and diagnosis of NL are crucial for appropriate management and treatment decisions.

PATIENT CONCERNS

We report a case of PAL in a 64-year-old female whose initial symptoms were pain and weakness in the left leg, which progressively worsened. In the half month before admission, the patient also showed signs of cranial nerve damage, such as diplopia and facial asymmetry.

DIAGNOSIS

Computed tomography of the abdomen revealed an occupying lesion in the left adrenal region. Electromyography and somatosensory evoked potential examination of the extremities suggested left lumbar plexus damage and complete damage to the right facial nerve. Adrenal biopsy confirmed diffuse large B-cell lymphoma.

INTERVENTIONS

The patient was treated with the R-CHOP scheme (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) combined with lenalidomide.

OUTCOME

After 6 rounds of chemotherapy, the symptoms improved slightly. However, the condition progressed, and the patient passed away 1 year later.

LESSONS

Due to the nonspecific clinical presentation, patients with neurological damage should be alerted to the possibility of PAL and need to be evaluated thoroughly.

Primary perineuritis, a rare but treatable neuropathy: Review of perineurial anatomy, clinicopathological features, and differential diagnosis

The perineurium surrounds each fascicle in peripheral nerves, forming part of the blood-nerve barrier. We describe its normal anatomy and function. "Perineuritis" refers to both a nonspecific histopathological finding and more specific clinicopathological entity, primary perineuritis (PP). Patients with PP are often assumed to have nonsystemic vasculitic neuropathy until nerve biopsy is performed. We systematically reviewed the literature on PP and developed a differential diagnosis for histopathologically defined perineuritis. We searched PubMed, Embase, Scopus, and Web of Science for "perineuritis." We identified 20 cases (11 M/9F) of PP: progressive, unexplained neuropathy with biopsy showing perineuritis without vasculitis or other known predisposing condition. Patients ranged in age from 18 to 75 (mean 53.7) y and had symptoms 2-24 (median 4.5) mo before diagnosis. Neuropathy was usually sensory-motor (15/20), painful (18/19), multifocal (16/20), and distal-predominant (16/17) with legs more affected than arms. Truncal numbness occurred in 6/17; 10/18 had elevated cerebrospinal fluid (CSF) protein. Electromyography (EMG) and nerve conduction studies (NCS) demonstrated primarily axonal changes. Nerve biopsies showed T-cell-predominant inflammation, widening, and fibrosis of perineurium; infiltrates in epineurium in 10/20 and endoneurium in 7/20; and non-uniform axonal degeneration. Six had epithelioid cells. 19/20 received corticosteroids, 8 with additional immunomodulators; 18/19 improved. Two patients did not respond to intravenous immunoglobulin (IVIg). At final follow-up, 13/16 patients had mild and 2/16 moderate disability; 1/16 died. Secondary causes of perineuritis include leprosy, vasculitis, neurosarcoidosis, neuroborreliosis, neurolymphomatosis, toxic oil syndrome, eosinophilia-myalgia syndrome, and rarer conditions. PP appears to be an immune-mediated, corticosteroid-responsive disorder. It mimics nonsystemic vasculitic neuropathy. Cases with epithelioid cells might represent peripheral nervous system (PNS)-restricted forms of sarcoidosis.

Central Diabetes Insipidus in a Patient With Lymphoma: A Case Report

Primary central nervous system (CNS) lymphoma or systemic non-Hodgkin lymphoma that infiltrates the CNS can cause central diabetes insipidus (CDI). Polyuria and polydipsia should raise the suspicion of CDI development in patients with lymphoma that infiltrates the CNS. CDI is effectively treated with desmopressin. However, careful monitoring of the patient's serum sodium, fluid intake, urine output, and weight is necessary because patients receiving desmopressin may develop hyponatremia, so they should be alert to recognize this side effect promptly. Moreover, CDI due to lymphoma can occasionally be reversible. Therefore, the dosage of desmopressin should be adapted during or after the treatment of lymphoma.

A severe case of neuroleukemiosis caused by B cell chronic lymphocytic leukemia, presenting as mononeuritis multiplex

AIMS

To report an exceptional case of nerve infiltration by an otherwise benign chronic B cell leukemia, inducing severe mononeuritis multiplex.

METHODS

The patient underwent extensive evaluation, including nerve conduction study and myography, brain and plexus MRI and nerve biopsy.

RESULTS

The clinical and electrophysiological diagnosis was a mononeuritis multiplex with severe motor and sensory involvement; only the nerve biopsy allowed definite diagnosis and introduction of chemotherapy, leading to resolution of sensory deficit and progressive motor improvement.

DISCUSSION

Neuroleukemiosis caused by chronic lymphoid leukemia is an exceptional diagnosis. The presence of other possible causes like cryoglobulinemia could induce avoidance of nerve biopsy thus undertreating patient, since steroid treatment is not expected to be efficient on lymphocytic proliferation. Our case stretches the importance of nerve biopsy and raises neuromuscular specialist's awareness of this rare entity.

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.

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.

[Oculomotor nerve palsy with preserved pupillary reaction in two cases of neurolymphomatosis]

Case 1: A 64-year-old woman with acute ptosis and diplopia was admitted to our hospital. She had right oculomotor nerve palsy with preserved pupillary reaction without any other neurological deficits. MRI showed abnormal enhancement in the right oculomotor nerve. An ovarian tumor was detected on CT examination, and was pathologically diagnosed as diffuse large B-cell lymphoma (DLBCL). Cerebrospinal fluid cytology disclosed malignant lymphoma cells. Based on the above findings, we concluded that she had neurolymphomatosis (NL) of the right oculomotor nerve. Case 2: A 63-year-old woman was admitted to our hospital due to weakness of the bilateral lower extremities and gait disturbance. Lumbar MRI showed enhanced lesions in the cauda equina, and we diagnosed her as having DLBCL based on bone marrow aspiration study. She later developed right oculomotor nerve palsy with preserved pupillary reaction together with the right abducens and hypoglossal nerve palsies, which were caused by NL. Our cases suggest that oculomotor nerve palsy with preserved pupillary reaction can be a clinical feature of NL. Although NL mainly affects the subperinerium, as parasympathetic fibers are located in the periphery of the oculomotor nerve and supplied by pia matar blood vessels, patients with NL may shows this clinical feature.

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.

Clinical and magnetic resonance imaging features of lymphoma involving the nervous system in cats

Background

Lymphoma is the most common spinal cord neoplasm and second most common intracranial tumor in cats, but description of specific magnetic resonance imaging (MRI) features is lacking.

Objective

Describe the clinical and MRI features of lymphoma affecting the central (CNS) or peripheral (PNS) nervous system or both in cats.

Animals

Thirty‐one cats with confirmed cytological or histopathological diagnosis or both of lymphoma involving the CNS or PNS or both, and MRI findings of the lesions.

Methods

Multicenter retrospective descriptive study. Signalment and medical information were recorded. Magnetic resonance imaging findings were reviewed by 3 observers following a list of predefined criteria and consensus was sought. Frequency distributions of the different categorical data were reported.

Results

Median duration of clinical signs at time of presentation was 14 days (range, 1‐90). Neurological examination was abnormal in 30/31 cats. On MRI, lesions affecting the CNS were diagnosed in 18/31 cats, lesions in both CNS and PNS in 12/31, and lesions in the PNS only in 1/31. Intracranial lesions were diagnosed in 22 cats (extra‐axial, 7/22; intra‐axial, 2/22; mixed, 13/22), and spinal lesions were diagnosed in 12 (6/12 involving the conus medullaris and lumbosacral plexuses). Infiltration of adjacent extra‐neural tissue was present in 11/31 cases. Contrast enhancement was seen in all lesions, being marked in 25/30. Meningeal enhancement was present in all but 2 cases. Several distinct MRI patterns were observed.

Conclusions and Clinical Importance

Nervous system lymphoma in cats has a wide range of MRI features, of which none is pathognomonic. However, together with clinical data and cerebrospinal fluid (CSF) analysis, MRI may provide a strong tentative antemortem diagnosis.

Neurolymphomatosis related to direct epineural invasion of the superficial peroneal nerve from subcutaneous B-cell lymphoma

Neurolymphomatosis is a rare complication of systemic lymphomas, and is classically related to hematogenous spread or intraneural spread of tumor cells from the leptomeninges. Here we report a case of neurolymphomatosis related to direct epineural invasion of the superficial peroneal nerve from subcutaneous localization of B-cell lymphoma. Nerve biopsy revealed striking histological features suggestive of contiguous infiltration of the superficial peroneal nerve by subcutaneous lymphoma. We think this case report sheds new light on neurolymphomatosis pathophysiology with an unreported mechanism in B-cell lymphoma. It also points out that the clinical spectrum in neurolymphomatosis is really variable, pure sensory mononeuritis being a rare presentation. Finally, our case is also strongly illustrative of the contribution of early nerve ultrasonography in the patient diagnosis and in guidance of the nerve biopsy.

F-18 Fluorodeoxyglucose Positron Emission Tomography Computed Tomography Findings in an Interesting Case of Primary Cauda Equina Lymphoma with Literature Review

Primary lymphomatous involvement of spinal cord, nerve roots, and cauda equina is a rare entity and comprises only 0.1% of extra-nodal lymphoma spectrum. Here, we present a case of non-Hodgkin lymphoma involving cauda equina, initially suspected as ependymoma on magnetic resonance imaging that was later confirmed on nerve root biopsy as high B cell non-Hodgkin's lymphoma of L1-S1 nerve roots. F-18 fluorodeoxyglucose positron emission tomography-computed tomography was performed for staging workup which showed abnormal metabolic activity within the spinal canal from D10-S2 with no evidence of distant organ involvement.

Fried egg sign: A typical ultrasonography feature of neurolymphomatosis

Neurolymphomatosis (NL) is a rare condition caused by non-Hodgkin's lymphoma or leukemia. We present a case of NL and describe ultrasound features, including the "fried egg sign" in which there is a clear demarcation between an avascular echogenic core and a hypoechoic vascularized peripheral zone that may help to distinguish NL from primary nerve sheath tumors.

Perineural spread of peripheral neurolymphomatosis to the cauda equina

OBJECTIVE

Neurolymphomatosis (NL) is a rare manifestation of lymphoma confined to the peripheral nervous system that is poorly understood. It can be found in the cauda equina, but extraspinal disease can be underappreciated. The authors describe how extraspinal NL progresses to the cauda equina by perineural spread and the implications of this on timely and safe diagnostic options.

METHODS

The authors used the Mayo Clinic medical records database to find cases of cauda equina NL with sufficient imaging to characterize the lumbosacral plexus diagnosed from tissue biopsy. Demographics (sex, age), clinical data (initial symptoms, cerebrospinal fluid, evidence of CNS involvement, biopsy location, primary or secondary disease), and imaging findings were reviewed.

RESULTS

Ten patients met inclusion and exclusion criteria, and only 2 of 10 patients presented with cauda equina symptoms at the time of biopsy, with 1 patient undergoing a cauda equina biopsy. Eight patients were diagnosed with diffuse large B-cell lymphoma, 1 with low-grade B-cell lymphoma, and 1 with mantle cell lymphoma. Isolated spinal nerve involvement was identified in 5 of 10 cases, providing compelling evidence regarding the pathophysiology of NL. The conus medullaris was not radiologically involved in any case. Lumbosacral plexus MRI was able to identify extraspinal disease and offered diagnostically useful biopsy targets. FDG PET/CT was relatively insensitive for detecting disease in the cauda equina but was helpful in identifying extraspinal NL.

CONCLUSIONS

The authors propose that perineural spread of extraspinal NL to infiltrate the cauda equina occurs in two phases. 1) There is proximal and distal spread along a peripheral nerve, with eventual spread to anatomically connected nerves via junction and branch points. 2) The tumor cells enter the spinal canal through corresponding neural foramina and propagate along the spinal nerves composing the cauda equina. To diffusely infiltrate the cauda equina, a third phase occurs in which tumor cells can spread circumdurally to the opposite side of the spinal canal and enter contralateral nerve roots extending proximally and distally. This spread of disease can lead to diffuse bilateral spinal nerve disease without diffuse leptomeningeal spread. Recognition of this phasic mechanism can lead to identification of safer extraspinal biopsy targets that could allow for greater functional recovery after appropriate treatment.

Intravascular large B-cell lymphoma affecting multiple cranial nerves: A histopathological study

Intravascular large B‐cell lymphoma (IVLBCL) is a rare form of lymphomas with poor prognosis, characterized by atypical lymphocytes selectively growing within the lumen of small or medium‐sized vessels. Here, we report a case of intracerebral IVLBCL in a 54‐year‐old man who died three months after symptom onset. The diagnosis was made by postmortem pathological examination, based on the identification of multiple ischemic lesions, with small or medium‐sized vessels filled with malignant B‐cells, in the cerebral hemispheres, cerebellum, midbrain, and medulla oblongata, including the external cuneate nucleus and trigeminal spinal tract nucleus. Apart from necrotic lesions, specific histopathological search for occluded vessels in the other brain stem structures permitted identification of significant involvement of the cuneate nucleus, solitary tract nucleus, hypoglossal nucleus, and inferior olivary complex. Small vessels affected by IVLBCL were also found in the trunks of the oculomotor, trigeminal, glossopharyngeal, vagal, and hypoglossal nerves. These histopathological findings were consistent with some cranial nerve symptoms/signs ascertained during hospitalization, such as diplopia, dysphonia, and asymmetry/hypomotility of the palatal veil. The case study presented here reports novel insights on radiological, anatomical, and clinical correlations of the IVLBCL, including the possible involvement of nuclei and trunks of multiple cranial nerves. The reported findings may help clinicians in the early identification of this rapidly progressive disease that can be easily misdiagnosed, through integrated neuroradiological, neurological and neuropathological approaches.

Primary Cauda Equina Lymphoma Treated with CNS-Centric Approach: A Case Report and Literature Review

Primary cauda equina lymphoma is an extremely rare entity previously documented in only 24 reported cases. Primary cauda equina lymphoma represents a subtype of neurolymphomatosis, which occurs when lymphoma cells with neurotropism infiltrate and destroy peripheral nerves, spinal nerve roots, nerve plexuses and cranial nerves. The cauda equina is an anatomic structure located in the lower part of the spinal canal consisting of multiple lumbar and sacral nerve roots. Herein, we report a unique case of primary cauda equina diffuse large B-cell lymphoma presenting as a tumor mass in the lower spinal canal, which was treated with a CNS-centric treatment approach followed by autologous hematopoietic stem cell transplantation.

Mechanisms of Nerve Damage in Neuropathies Associated with Hematological Diseases: Lesson from Nerve Biopsies

Despite the introduction of non-invasive techniques in the study of peripheral neuropathies, sural nerve biopsy remains the gold standard for the diagnosis of several neuropathies, including vasculitic neuropathy and neurolymphomatosis. Besides its diagnostic role, sural nerve biopsy has helped to shed light on the pathogenic mechanisms of different neuropathies. In the present review, we discuss how pathological findings helped understand the mechanisms of polyneuropathies complicating hematological diseases.

Systemic ALK-positive anaplastic large cell lymphoma with bilateral optic neurolymphomatosis resulting in permanent blindness

ALK-positive ALCL can lead to rapid irreversible destruction of the optic pathway. Early treatment should be instituted in patients with CNS involvement or those at increased CNS risk.

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.

From pathogenesis to personalized treatments of neuropathies in hematological malignancies

The peripheral nervous system may be involved at any stage in the course of several hematological diseases, the most common being monoclonal gammopathies (of undetermined significance or malignant) or lymphomas. The underlying pathogenic mechanisms are different and therapies aim at targeting the dangerous either B-cell or plasma cell clones. Recently, high-throughput technologies, and next-generation sequencing have increased our knowledge of hematological diseases pathogenesis by the identification of somatic mutation affecting pivotal signaling pathways. Accordingly, new target therapies are used that may also be borrowed for treatment of neuropathies in hematological diseases.

Neurolymphomatosis, a rare manifestation of peripheral nerve involvement in lymphomas: Suggestive features and diagnostic challenges

Neurolymphomatosis, the infiltration of the peripheral nervous system from lymphoid cells, represents an uncommon manifestation of lymphomas. We describe the challenging diagnostic work-up in a patient with neurolymphomatosis. A 58-year-old woman with previous breast diffuse large B-cell lymphoma treated with chemo- and radiation-therapy, presented with dysesthesias, neuropathic pain at left abdomen and thigh, and weakness at left lower limb 9 years after disease remission. Neurophysiology revealed left T10-L4 radiculo-plexopathy with no abnormalities at cerebrospinal fluid (CSF), nerve ultrasound, and ¹⁸ fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). MR-neurography disclosed left rectus abdominis muscle atrophy, neurogenic edema, and denervation. Radiation-induced damage, paraneoplastic, infectious radiculo-plexopathies, and atypical chronic inflammatory demyelinating polyradiculoneuropathy were ruled out. Neurolymphomatosis was suspected, and the patient treated with rituximab with improvement. Despite treatment, the radiculo-plexopathy eventually extended to the right side and sacral roots. Later in the disease course, sural nerve biopsy confirmed the diagnosis. Maintenance therapy was continued, until cutaneous localizations occurred, requiring salvage therapy and autologous stem cell transplant. Although rare, neurolymphomatosis should be considered in all patients with lymphomas and unexplained peripheral nervous system involvement. Hematological, CSF, and neuroimaging findings may be unremarkable, and a high index of suspicion required in order to achieve the diagnosis.

Magnetic Resonance Imaging-negative, Rituximab-resistant Neurolymphomatosis as a Paradoxical Presentation of Relapsed Primary Adrenal Lymphoma

Primary adrenal lymphoma (PAL) is rare and known to have a predilection for central nervous system (CNS) relapse. A 70-year-old man with a 2-year history of primary aldosteronism presented because of a fever. He was hypotensive, and his adrenal glands were unequivocally enlarged. PAL was diagnosed. Despite showing an initial response to immunochemotherapy, progressive paralysis ensued. Magnetic resonance imaging findings were negative, and rituximab was ineffective. His debilitated condition hindered further chemotherapy. A postmortem examination revealed lymphoma relapse in the systemic peripheral nerves. The sequential presentation of two rare lymphomas implies that PAL might have a predilection for not only the CNS but also peripheral nerves.

Recurrence of nasal type NK/T cell lymphoma presenting as neurolymphomatosis on 18F-FDG PET/CT: A case report and literature review

INTRODUCTION

NK/T cell lymphomas seldom involve the peripheral nervous system. We report a case of recurrent nasal type NK/T cell lymphoma presenting as neurolymphomatosis and its manifestation on F-FDG PET/CT.

PATIENT CONCERNS

A 55-year old man presented with a mass in the right nasal cavity was diagnosed with extranodal NK/T cell lymphoma, nasal type. F-FDG PET/CT showed intense FDG uptake within the mass. After radiotherapy the nasal tumor was completely relieved, but the patient experienced numbness and amyosthenia in the right upper extremity one week after completion of radiotherapy.

DIAGNOSIS

PET/CT showed intense FDG uptake in the brachial plexus, axillary, suprascapular and median nerves, suggestive of recurrence of lymphoma presenting as neurolymphomatosis.

INTERVENTIONS

After 1 cycle of chemotherapy, the follow-up PET/CT showed markedly reduced FDG uptake in the previous involved nerves, demonstrating a very good response of neurolymphomatosis to chemotherapy.

OUTCOMES

The patient finally had a progression free survival of 8 months after completion of 4 cycles of chemotherapy and autologous stem cell transplantation.

LESSONS

As neurolymphomatosis is a rare neurologic manifestation in recurrence of NK/T cell lymphoma, recognition of its presentation is important for prompt diagnosis and initiating treatment approach.

Primary Central Nervous System Lymphoma with Peripheral Nerve Involvement: Case Report

A 50-year-old man presented with dizziness and hearing disturbance in the right ear. Magnetic resonance imaging (MRI) revealed a well-enhanced mass lesion in the right cerebellopontine (CP) angle that appeared to originate in the cerebellum. A surgical specimen obtained at the subtotal resection with craniotomy revealed a diffuse large B-cell lymphoma (DLBCL). During the three courses of chemotherapy with high-dose methotrexate (MTX) with leucovorin rescue, he developed a right abducens palsy, left oculomotor palsy, left facial palsy, right trigeminal sensory disturbance, and paraparesis. Although the brain MRI showed that the CP angle tumor had disappeared completely following chemotherapy, enhanced lesions along the cauda equina were detected on a lumbar spine MRI. FDG-PET (18 F-fluorodeoxyglucose positron emission tomography) revealed multiple high-uptake abnormalities in the cranial nerves and spinal nerves. Tumor cells were found in the cerebrospinal fluid specimen from a lumbar puncture. Craniospinal irradiation was performed, including all the abnormal FDG high-uptake areas, and was effective in relieving the patient's symptoms. On FDG-PET, the high-uptake abnormalities in the peripheral nerves disappeared. However, five weeks after the irradiation, he developed right trigeminal sensory disturbance, hoarseness, dysphagia, and right arm pain. FDG-PET disclosed multiple high-uptake abnormalities in more peripheral portions of the cranial nerves and spinal nerves. Chemotherapy with rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine (Oncovin®), and prednisolone (R-CHOP) was then resorted to which mitigated his symptoms. On follow-up FDG-PET, the high-uptake abnormalities in the peripheral nerves disappeared again.

CD56+ B-cell Neurolymphomatosis in a Cat

A 16-year-old male Russian blue cat was presented with acute onset of paraparesis of the forelimbs that progressed to tetraparesis. Neurological examination revealed non-ambulatory tetraparesis with decreased postural reactions in all four limbs. Magnetic resonance imaging revealed multifocal nerve root swelling on the right at C6/C7 and C7/T1, while ultrasonography demonstrated swelling of the right brachial plexus. To understand the cause of the nerve swelling, the right musculocutaneous nerve arising from the brachial plexus and the pectoralis muscle were biopsied. Histologically, there was evidence of neurolymphomatosis (neurotropic lymphoma) with Wallerian degeneration and denervation atrophy of myofibres. The neoplastic lymphoid cells expressed CD79a, CD20 and CD56. Based on these findings, a diagnosis of B-cell neurolymphomatosis was made. Expression of CD56, synonymous with neural cell adhesion molecule, is rare in B-cell lymphomas and has not been reported in feline B-cell lymphomas or feline neurolymphomatosis. CD56 expression was suspected to have played an important role in neurotropism of the neoplastic cells in this case.

Neurolymphomatosis caused by T-cell lymphosarcoma in a cat: imaging description and treatment review

Case summary

A 16-year-old domestic shorthair cat was evaluated for acute-onset right pelvic limb monoparesis localized to the sciatic nerve. MRI revealed a homogeneously contrast-enhancing, well-demarcated mass effacing the right sciatic nerve from its intravertebral origin to the end of the viewable field (mid-femur). Abdominal ultrasound revealed thickened small intestinal loops and enlarged mesenteric lymph nodes. Cytology of the small intestine was suggestive of lymphosarcoma. T-cell lymphosarcoma of the sciatic nerve and small intestines was confirmed with incisional biopsy. Treatment consisted of systemic chemotherapy with vincristine followed by the Wisconsin–Madison feline lymphosarcoma protocol, but despite treatment the patient neurologically worsened and was euthanized after 54 days.

Relevance and novel information

We present herein one of the first descriptions of neurolymphomatosis in the domestic cat that included post-intravenous contrast MRI. Treatment options based on recommendations for people with neurolymphomatosis include systemic chemotherapy, intrathecal chemotherapy and/or localized radiation chemotherapy. The authors recommend that all cats be screened for concurrent non-neuronal areas of lymphosarcoma before undergoing treatment for neurolymphomatosis, regardless of clinical signs.

Peripheral nervous system involvement in lymphomas

The peripheral nervous system may be involved at any stage in the course of lymphoproliferative diseases. The different underlying mechanisms include neurotoxicity secondary to chemotherapy, direct nerve infiltration (neurolymphomatosis), infections, immune-mediated, paraneoplastic or metabolic processes and nutritional deficiencies. Accordingly, the clinical features are heterogeneous and depend on the localization of the damage (ganglia, roots, plexi, and peripheral nerves) and on the involved structures (myelin, axon, and cell body). Some clinical findings, such a focal or diffuse involvement, symmetric or asymmetric pattern, presence of pain may point to the correct diagnosis. Besides a thorough medical history and neurological examination, neurophysiological studies, cerebrospinal fluid analysis, nerve biopsy (in selected patients with suspected lymphomatous infiltration) and neuroimaging techniques (magnetic resonance neurography and nerve ultrasound) may be crucial for a proper diagnostic workup.

Two-year-old female with EBV-positive diffuse large B-cell lymphoma and subsequent CNS involvement with neurolymphomatosis

We describe a case of Epstein-Barr virus (EBV) positive, diffuse large B-cell lymphoma in a 2-year-old female who went on to develop relapsed/refractory central nervous system (CNS) disease, manifesting as cranial nerve neurolymphomatosis. Although her atypical presentation was thought to be associated with an immune deficiency, extensive work-up was negative. Despite subsequent treatment with third-party EBV-specific cytotoxic T-lymphocytes, she died of progressive disease. This case report raises questions as to whether tailored treatment approaches should be considered for atypical presentations of pediatric lymphoma (e.g., CNS and virus-associated).

Neurolymphomatosis in the Cauda Equina Diagnosed by an Open Biopsy

Neurolymphomatosis is a rare form of extranodal malignant lymphoma defined as the infiltration of malignant lymphocytes into the central or peripheral nerve. We herein report a case of neurolymphomatosis in the cauda equina diagnosed by an open surgical biopsy. He presented with muscle weakness, atrophy, numbness and hypoesthesia in the bilateral lower extremities with the accumulation of ¹⁸fluoro-2-deoxyglucose (FDG) in the bilateral cauda equina. Cerebrospinal fluid cytology (three times) and flow cytometry (two times) and biopsies of the left sural nerve, bone marrow, paranasal sinus and left testis were all negative for malignancy, so finally we performed a surgical open biopsy of the cauda equina by laminectomy and diagnosed him with diffuse large B-cell lymphoma in the cauda equina. He was successfully treated with the disappearance of the FDG accumulation for a long time. The present case suggested that an early open biopsy of the cauda equina may be considered for cases of suspected neurolymphomatosis in the cauda equina for a good outcome.

CD3 and CD20 co-expression in a case of canine peripheral T-cell lymphoma with prominent cardiac and peripheral nerve involvement

An 8-y 9-mo-old male Pug dog was presented because of anorexia, hindlimb ataxia, vomiting, and progressive weight loss. Clinical examinations revealed atrophic hindlimb muscles with decreased postural reaction, enlargement of the cardiac silhouette and megaesophagus on radiograph, and reduced cardiac contractility on ultrasonography. The dog died 10 d after the initial examination, and an autopsy was performed. Grossly, the heart was enlarged, with multifocal-to-coalescing extensive plaque-like areas of discoloration on the epicardial surface. On cross-section, the ventricles were moderately dilated, and discoloration extended into the myocardium. Peripheral lymph nodes were of normal size. Histologically, atypical lymphoid cells replaced the myocardium and also extensively infiltrated peripheral nerve bundles in various organs. With immunohistochemistry, the neoplastic cells exhibited strong immunoreactivity for CD3 and CD20, and were negative for CD8, granzyme B, CD79α, and Pax5. Double-label immunofluorescence confirmed co-expression of CD3 and CD20 by the neoplastic cells. Molecular clonality analysis presented a clonal T-cell receptor gamma gene rearrangement. The case was diagnosed as a CD3+/CD20+ peripheral T-cell lymphoma with prominent cardiac and peripheral nerve involvement, indicating neurolymphomatosis.

Homonymous Hemianopia: A Rare Presentation of Secondary Central Nervous System Neurolymphomatosis

Neurolymphomatosis is an atypical complication of non-Hodgkin lymphoma and leukaemia involving infiltration of neurotropic neoplastic cells in the central or peripheral nervous system. A 28-year-old Malay lady with background diffuse large B-cell lymphoma stage IV presented with left homonymous hemianopia associated with cognitive function deterioration. Her best corrected visual acuity was 6/9 in both eyes. Magnetic resonance imaging (MRI) of the brain showed a lesion suggestive of secondary lymphomatous infiltration of the splenium of corpus callosum. The patient underwent chemotherapy, after which repeated MRI showed a reduction in the lesion size. Homonymous hemianopia is a rare presentation of secondary central nervous system neurolymphomatosis. A comprehensive history, physical examination, and radiological imaging are essential to establish the diagnosis in patients presenting with visual field defects.

First pathological report of a de novo CD5-positive diffuse large B-cell lymphoma patient presenting with Guillain-Barré syndrome-like neuropathy due to neurolymphomatosis

Peripheral neuropathy occurs in approximately 5% of the patients with lymphoma. Two major causes of peripheral neuropathy associated with lymphoma are neurolymphomatosis and paraneoplastic neuropathy such as demyelinating neuropathy. The differential diagnosis between neurolymphomatosis and demyelinating neuropathy is difficult, because electrophysiological findings suggestive of demyelination are frequently observed even in patients with neurolymphomatosis. Here, we report a patient with de novo CD5-positive diffuse large B-cell lymphoma (DLBCL) who presented with Guillain-Barré syndrome (GBS)-like neuropathy. Demyelination due to paraneoplastic neuropathy was clinically suspected. However, autopsy demonstrated that the cause of the neuropathy was neurolymphomatosis. Clinical courses of neurolymphomatosis vary and neurolymphomatosis cases presenting with GBS-like neuropathy are reported. In addition, DLBCL is the most frequent histological type of malignant lymphoma that develops neurolymphomatosis. Furthermore, "CD5-positive" DLBCL may tend to develop neurolymphomatosis. If a patient with "CD5-positive" DLBCL develops peripheral neuropathy, neurolymphomatosis should be considered and imaging studies performed and, if possible, nerve tissue biopsy, regardless of clinical symptoms of the neuropathy. To our knowledge, this is the first report of a patient with de novo CD5-positive DLBCL with neurolymphomatosis who presented with GBS-like neuropathy.

[A case of neurolymphomatosis presented as cauda equine syndrome accompanied with M-proteinemia]

A 63-year-old man developed a syndrome of cauda equine, with the numbness which is a left lower extremity from the left buttocks, weakness of left leg, and a dysfunction of bladder and bowel. Enhanced MRI revealed the enhancement of lower cauda equine, and a nerve conduction test revealed decreased F-wave persistency in the tibial nerve and increased F-wave latency in the peroneal nerve on the both sides. M-proteinemia was admitted and myeloma was suspected. By a biopsy of a vertebral arch, we diagnosed with diffuse large B-cell lymphoma. We treated with dexamethasone and R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone (prednisolone)), then the symptom was improved. In case of caude equine syndrome with M-proteinemia, a possibility of the malignant lymphoma should also be considered.

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.

[A case of neurolymphomatosis that was diagnosed by acoustic nerve biopsy]

A 58-year-old female was admitted to our hospital because of recurrent multiple cranial neuropathy (right facial palsy followed by involvement of the left trigeminal, facial, acoustic, pharyngeal, and vagal nerves and the right abducens nerve). Brain MRI showed gadolinium enhancement of the right abducens, bilateral facial/acoustic, and left pharyngeal/vagal nerves, and ¹⁸F-Fluorodeoxyglucose (FDG)-positron emission tomography revealed abnormal FDG uptake in the right facial, acoustic, pharyngeal, and vagal nerves and the left cervical lymph nodes. Blood and biochemical analyses did not show any abnormalities, including in the patient's lactate dehydrogenase and soluble interleukin-2 receptor (sIL2R) levels. A cerebrospinal fluid (CSF) examination showed gradual increases in the patient's cell counts and protein, β2-microglobulin, and sIL2R levels, but no malignant cells were detected. A thorough investigation involving repeated CSF examinations, whole-body computed tomography, bone marrow aspiration, random skin biopsies, and cervical lymph node aspiration biopsy examinations did not result in any definitive conclusions. Steroid therapy was ineffective, and the patient developed deafness in her left ear. Therefore, we performed a biopsy examination of the left acoustic nerve, which resulted in the patient being diagnosed with diffuse large B-cell lymphoma. High-dose MTX following the intrathecal administration of MTX, cytarabine, and prednisolone partially improved her symptoms, but she died after several episodes of clinical recurrence. Acoustic nerve biopsy may help diagnose neurolymphomatosis in carefully selected cases.

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.

Plexus and peripheral nerve metastasis

Cancer in the form of solid tumors, leukemia, and lymphoma can infiltrate and metastasize to the peripheral nervous system, including the cranial nerves, nerve roots, cervical, brachial and lumbosacral plexuses, and, rarely, the peripheral nerves. This review discusses the presentation, diagnostic evaluation, and treatment options for metastatic lesions to these components of the peripheral nervous system and is organized based on the anatomic distribution. As skull base metastases (also discussed in Chapter 14) result in cranial neuropathies, these will be covered in detail, as well as cancers that directly infiltrate the cranial nerves. Particular emphasis is placed on the clinical, imaging, and electrodiagnostic features that differentiate neoplastic plexopathies from radiation-induced plexopathies. Neurolymphomatosis, in which malignant lymphocytes invade the cranial nerves, nerve roots, brachial and lumbosacral plexuses, and peripheral nerves, is a rare manifestation of lymphoma and leukemia. Diagnoses of neurolymphomatosis are often missed or delayed given its varied presentations, resulting in poorer outcomes. Thus this disease will also be discussed in depth.

Neurolymphomatosis: A Surreal Presentation of Lymphoma

Background:

Neurolymphomatosis is a neurologic complication poorly recognized by neurologists and oncologists and presents usually several months after successful treatment of systemic lymphoma. Other disorders that must be differentiated from these entities include peripheral-nerve or nerve root compression and paraneoplastic neuropathy.

Aim:

To describe the unusual occurrence of neurolymphomatosis in a patient of B-cell lymphoma.

Method:

Diagnosis was made by demonstration of enhancement of nerve roots on Magnetic Resonance Imaging of the brachial, lumbosacral plexus, peripheral nerves or by increased hyper-metabolic activity along the course of affected nerves on fluorodeoxyglucose positron emission tomography (FDG-PET).

Results and Conclusion:

MRI and PET-CT are imaging modalities of choice for evaluation of patients with lymphoma and suspected neural involvement. Treatment of neurolymphomatosis consists of focal radiotherapy and high-dose methotrexate therapy.

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.

Neurolymphomatosis in Primary Cutaneous CD4+ Pleomorphic Small/Medium-sized T-cell Lymphoma Mimicking Hansen's Disease

Neurolymphomatosis (NL) refers to nerve infiltration by neurotropic neoplastic cells in the setting of a known or an unknown hematological malignancy. It typically presents as painful or painless peripheral mononeuropathy, mononeuritis multiplex, polyneuropathy, polyradiculopathy, or cranial neuropathy. A 32-year-old male presented with a hyperpigmented hypoesthetic plaque over the anterolateral aspect of the right leg with thickening of the right common peroneal nerve and foot drop clinically diagnosed as Hansen's disease. Biopsy taken from skin showed infiltrates of pleomorphic small and medium sized lymphocytes in the dermis and subcutis. On immunohistochemistry, the cells were positive for CD3, CD4 and negative for CD8, CD20, and CD30. Ultrasonography-guided fine-needle aspiration of the thickened nerve showed infiltrates of atypical lymphoid cells. Based on these findings, a diagnosis of NL in primary cutaneous CD4+ pleomorphic small/medium-sized T-cell lymphoma was made. The disease responded to systemic chemotherapy and localized radiotherapy with no evidence of relapse during 3 years follow-up. NL in primary cutaneous CD4+ pleomorphic small/medium-sized T-cell lymphoma presenting with manifestations redolent of Hansen's disease is not described in available literature. This case also demonstrates the utility of fine needle aspiration of nerve, a minimally invasive procedure in the diagnosis of NL.

Two Cases of Neurolymphomatosis with Fatal Bilateral Vocal Cord Paralysis that were Diagnosed with 18F-fluorodeoxyglucose Positron Emission Tomography (FDG PET)/CT

Neurolymphomatosis is a rare entity defined as nerve infiltration by neurotropic abnormal lymphocytes which can lead to the development of neuropathy, with typical presentations including pain, hypoesthesia, paresthesis and palsy. We herein report two cases where critical bilateral vocal cord paralysis due to neurolymphomatosis in recurrent nerves occurred in refractory Burkitt lymphoma and adult T-cell lymphoma patients. High-dose methotrexate and intrathecal chemotherapy injection for the nervous lesions were ineffective, and the patients died. Neurolymphomatosis of the recurrent nerve is an emergent and difficult complication and should be suspected when sudden onset of aphasia, hoarseness or shortness of breath is found in refractory lymphoma patients.

18F-FDG PET/CT/MRI Fusion Images Showing Cranial and Peripheral Nerve Involvement in Neurolymphomatosis

We report a 56-year-old female patient with non-Hodgkin's diffuse large B cell lymphoma (NHL) who, on magnetic resonance imaging (MRI) with a T1 weighted and gadolinium-enhanced imaging, was found to have thickening and infiltration in 75% of peripheral nerves of the patient and enlargements of cranial nerves, possibly related to lymphomatous infiltration. Subsequent positron emission tomography/computed tomography (PET/CT) using ¹⁸F-labeled 2-deoxy-2-fluoro-d-glucose (¹⁸F-FDG) showed widespread active involvement of the cervical plexus, bilateral peripheral nerves, right femoral nerve, the parasellar region of the skull, and marked hypermetabolism in the left trigeminal ganglia. This case re-emphasizes that while CT and MRI provide anatomical details, ¹⁸F-FDG PET/CT images better delineate the metabolic activity of neurolymphomatosis (NL) in the peripheral and central nervous system.

Diagnostic and response assessment FDG PET-CT in neurolymphomatosis

FDG PET-CT is a useful imaging tool in the diagnosis and response assessment of neurolymphomatosis, especially in cases of otherwise unexplained neuropathy following conventional diagnostic work-up including lumbar puncture, CT, and MRI. The use of a novel PET reconstruction algorithm improves image quality and lesion detection through increased signal-to-noise ratio.

An Extremely Rare Intersection: Neurolymphomatosis in a Patient with Burkitt Lymphoma Detected by 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Neurolymphomatosis (NL) is a rarely seen neurologic involvement of the systematic lymphoma. Its diagnosis is challenging, and requires biopsy. In cases where biopsy is not appropriate, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) may aid in diagnosis. Here, we present a 54-year old male patient diagnosed with Burkitt lymphoma who underwent FDG-PET/CT in order to evaluate the treatment response after chemotherapy and radiotherapy. On viewing PET/CT images of the patient who complained of pain and weakness in his upper extremities after therapy, linear FDG uptake was observed in bilateral cervical 5 (C5), left cervical 6 (C6), bilateral cervical 7 (C7), and right lumbar 4 (L4) nerve roots. Magnetic resonance imaging (MRI) revealed dilation and thickening of nerve roots consisted with FDG uptake observed on PET/CT images. Since biopsy was not performed, histopathological diagnosis could not be established. However, overlapping of clinical, PET/CT, and MRI findings strongly suggested the presence of NL. As is the case of this patient, in cases with non-Hodgkin lymphoma, a combined evaluation of FDG-PET/CT and MRI modalities aid in the establishment of the diagnosis of NL.

Splenic marginal zone lymphoma: An indolent malignancy leading to the development of neurolymphomatosis

INTRODUCTION

Acute neuropathic pain and weakness with a sensory level in a patient with a history of lymphoma has a broad differential diagnosis. Evaluation of such a presentation often includes MRI, neurophysiologic studies, and cerebrospinal fluid evaluation. We report a patient with splenic marginal zone lymphoma who developed acute weakness, sensory loss, and neuropathic pain due to neurolymphomatosis.

METHODS

Clinical evaluation, MRI of the lumbar spine, cerebrospinal fluid evaluation, electrodiagnostic (EDx) studies, and biopsy of a dorsal nerve root were undertaken.

RESULTS

EDx studies were consistent with an acute, acquired demyelinating sensorimotor polyradiculoneuropathy. Treatment with intravenous immunoglobulin and plasma exchange did not lead to clinical improvement. Ultimately, biopsy of a dorsal nerve root was performed and revealed neurolymphomatosis.

CONCLUSION

This case emphasizes that, when it can be performed safely, biopsy for suspected neurolymphomatosis is imperative for appropriate diagnosis and treatment. Muscle Nerve 55: 440-444, 2017.

The Diagnostic Dilemma of Neurolymphomatosis

Neurolymphomatosis (NL) defined as infiltration of the central nervous system or the peripheral nervous system (PNS) by malignant lymphoma cells is a rare clinical entity. However, the increasing use of fluorodeoxyglucose positron-emission tomography (FDG-PET) and magnetic resonance imaging in evaluating PNS disorders is resulting in; this condition being recognized more frequently. Here; we report five NL patients and review the current literature. We report five patients with non-Hodgkin's lymphoma (NHL) and NL, all of whom were men aged 47–69 years. The clinical presentation varied from symmetrical peripheral neuropathy to mononeuropathy. Peripheral neuropathy was the presenting manifestation of a systemic lymphoma in two patients (40%). Neuroimaging as well as whole-body FDG-PET helped in determining the correct diagnosis in all of the patients. NL is an unusual presentation of NHL resulting from infiltration of the PNS by malignant lymphomatous cells. While evaluating peripheral neuropathy, a high degree of suspicion of NL is required since the presenting symptoms vary, conventional radiology has only modest sensitivity, and a pathological diagnosis is often difficult. FDG-PET helps in the early diagnosis and treatment of this condition.