CIDP mimics: a case series

Background

To report our experience with a group of patients referred for refractory CIDP who fulfilled “definite” electrodiagnostic EFNS criteria for CIDP but were found to have an alternate diagnosis.

Methods

Patients who were seen between 2017 and 2019 for refractory CIDP that fulfilled “definite” electrodiagnostic ENFS criteria for CIDP, but had an alternate diagnosis, were included. Patients who correctly had CIDP, anti MAG neuropathy, or MMN with conduction block, were excluded from the study. Demographics, clinical and electrophysiological characteristics, pertinent workup, final alternate diagnoses, and outcomes were collected.

Results

Seven patients were included: POEMS (n = 5), CANOMAD (n = 1), and neurolymphomatosis (n = 1). Most patients reported neuropathic pain and leg swelling (n = 6) or significant weight loss (n = 4). All patients had a monoclonal protein, and most patients who were tested had an elevated VEGF and CSF cyto-albuminologic dissociation. Electrophysiology showed pronounced intermediate more than distal demyelination, and axonal loss in the lower extremities. Response to steroids or IVIG varied, but some patients did respond to these treatments, especially early in the disease.

Conclusion

Pain, systemic symptoms, suggestive electrophysiological findings, and/or a serum monoclonal protein should raise suspicion for CIDP mimics. Initial response to steroids or IVIG, over reliance on CSF, and electrophysiology findings can all be misleading.

Sciatic and median nerve neurolymphomatosis as initial presentation of B-cell Lymphoma

Neurolymphomatosis (NL) is the infiltration of cranial nerves or nerves and roots from the peripheral nervous system by lymphoma, usually by B-cell non-Hodgkin's lymphoma. It is uncommon as initial presentation of the disease and can lead to extremely heterogeneous clinical manifestations. We report the case of a 72-year old male who presented with numbness of the right hand, progressive weakness in both lower limbs and weight loss. 18F-FDG PET/CT showed bilateral hypermetabolic adrenal masses, gastric ulcer, small hypermetabolic adenopathies, multiple focal bone marrow uptake and intense uptake in both sciatic nerves and right median nerve. A node and gastric biopsy confirmed diffuse large-B-cell lymphoma, activated B cell type, with posterior resolution of peripheral nerves uptake after beginning chemotherapy.

Neurolymphomatosis: a single-center experience of neuromuscular manifestations, treatments, and outcomes

OBJECTIVES

Neurolymphomatosis (NL) is a disease characterized by the infiltration of malignant lymphocytes into the peripheral nervous system. We report clinical features, radiographic findings, modes of treatment, and outcomes of patients with NL.

METHODS

We retrospectively investigated patients with NL. We extracted data, including clinical features, magnetic resolution imaging (MRI), ¹⁸F-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scans, cerebrospinal fluid cytology findings, the results of electrodiagnostic studies, as well as patient treatments and outcomes.

RESULTS

Ten NL patients were identified. All patients reported pain/paresthesia and weakness in the affected area. The MRI scans were abnormal in eight out of nine patients with an enhancement of the spinal nerve root, plexus, peripheral nerve trunk, and cranial nerve. The FDG PET/CT scans were positive in all patients. Radiculopathy or radiculoplexopathy was the most common electrodiagnostic finding. Neurological improvement was observed in only three patients. The condition of the nine patients who underwent multimodality treatments for cancer eventually deteriorated and the patients died.

CONCLUSIONS

NL should be considered in the differential diagnosis of any type of neuropathy in patients with lymphoma. Because it could be confused with other neuropathies in lymphoma and various musculoskeletal diseases, a high index of suspicion and familiarity with clinical manifestation of NL are key. FDG PET/CT was the most sensitive diagnostic imaging modality to detect relevant neural invasion. The root within the spinal neural foramen was the most frequently affected neural structure. Early diagnosis of this rare neurologic manifestation of lymphoma may improve treatment outcomes.

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.

Neurological misdiagnoses of lymphoma

BACKGROUND

Lymphoma of the nervous system is rare and usually involves the brain, spinal cord, or peripheral nerves. Hence, it has varied clinical presentations, and correct diagnosis is often challenging. Incorrect diagnosis delays the appropriate treatment and affects prognosis. We report 5 patients with delayed diagnosis of lymphoma involving the central and/or peripheral nervous system, initially evaluated for other neurological diagnoses. We also discuss the challenge of diagnosis and appropriate testing.

METHODS

Retrospective review of 2011-2019 records of patients with confirmed nervous system lymphoma diagnosed in a tertiary care medical center.

RESULTS

We present 5 adult patients initially evaluated for inflammatory myelopathy, inflammatory lumbosacral plexopathy, atypical parkinsonism, and demyelinating disease of the CNS. Final diagnosis of the nervous system lymphoma was delayed by 4 to 18 months and was based on tissue biopsy in 4, and on CSF and bone marrow examination in 1 patient.

CONCLUSIONS

Lymphoma may imitate various central and peripheral nervous system disorders. We suggest several red flags that indicate the need to consider lymphoma, including subacute but progressive symptomatic evolution, painful neurological deficit, unclear clinical diagnosis, and transient steroid responsiveness. Correct diagnosis often requires a combination of diagnostic tests, while pathology testing is crucial for early diagnosis and is strongly recommended in the appropriate clinical setting.

Diffuse large B-cell lymphoma relapse presenting as extensive neurolymphomatosis

A 56-year-old woman with a history of diffuse large B-cell non-Hodgkin lymphoma (DLBCL-NHL) in remission for two years presented with weight loss and multifocal sensory/motor symptoms. Magnetic resonance imaging (MRI) of the neuraxis and whole-body FDG PET/CT led to a diagnosis of secondary neurolymphomatosis (NL). MRI demonstrated extensive thickening and enhancement of multiple cranial nerves and peripheral nerve plexuses with corresponding elevated metabolism on FDG PET/CT. Treatment with chemotherapy resulted in complete response on FDG PET/CT and subsequently she underwent autologous stem cell transplantation. NL is a rare manifestation of lymphoma affecting the peripheral nervous system. Nonspecific neuropathic symptoms make clinical diagnosis difficult. Though nerve biopsy is considered the gold standard, MRI and FDG PET/CT are accepted alternatives for making the diagnosis. We review imaging findings in NL, describe the differential diagnosis, and discuss the limitations of the imaging modalities.

Primary peripheral nerve tumors associated with nerve-territory herpes zoster

Herpes viruses have been described as markers of occult cancer and have also been implicated in oncogenesis. This group of viruses includes varicella-zoster virus (VZV) which is well-known for its ability to evade the immune response by lying dormant in the dorsal root ganglion of peripheral nerves. Although it is common knowledge that VZV reactivation causes herpes zoster (shingles), there have been no reports in literature of herpes zoster manifesting in the dermatomal territory of peripheral nerves involved by either benign or malignant tumors. We report two cases of patients with peripheral nerve tumors who presented with herpes zoster in the dermatomal distribution of the involved nerves. One patient had primary neurolymphomatosis, whereas the other had a sacral schwannoma. We believe these are the first cases to be reported that demonstrate herpes zoster at clinical presentation in patients with peripheral nerve tumors. This suggests that VZV may have the potential to cause peripheral nerve tumors via a complex interplay of viral oncogenes and alterations in host immunological responses.

Neurolymphomatosis of the lumbosacral plexus and its branches: case series and literature review

Background

Neurolymphomatosis (NL) is a direct process of invasion of peripheral nerves by lymphoma. It occurs in roughly 5% of patients with lymphoma and represents a particularly difficult diagnostic dilemma when it is the presenting focal manifestation of occult lymphoma.

Case presentation

We present 3 examples of invasion of the lumbosacral plexus and its branches. These cases demonstrate a protean clinical picture with regards to the time relationship to the clinical course of lymphoma and the neuroanatomical extent of lumbosacral plexus invasion. We demonstrate the complementary role of different imaging modalities. A review of the literature summarizes 23 reports where lumbosacral plexus invasion was the index manifestation, at the time of first diagnosis or recurrence of lymphoma. This series confirms the strong preponderance of B-cell type (92%). There is a marked predilection for involvement of the sciatic nerve (74%), either focally or in a longitudinally extensive fashion, from the ischium to the popliteal fossa. There can also be restricted and discrete involvement of tibial and fibular branches. In recent years, ultrasound and CT have been given a more limited role, as screening tools or as a guide for biopsy. MRI neurography and PET-CT have become leading diagnostic modalities for diagnosis, staging and assessment of treatment response.

Conclusion

The diagnosis of NL may be challenging, and it was once only reached at autopsy. Improved diagnostic imaging of focal or even asymptomatic disease offers new hope for earlier diagnosis and successful targeted therapy.

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.

Primary neurolymphomatosis of the trigeminal nerve

We report a case of a primary malignant lymphoma of the trigeminal nerve that was associated with facial pain. A 65-year-old man was examined at another hospital for unilateral facial pain. Carbamazepine was prescribed, but his symptoms did not improve. Magnetic resonance imaging (MRI) revealed swelling of the trigeminal nerve and a mass lesion in Meckel's cave. The patient was referred to our hospital at this point. Gadolinium-enhanced MRI and F18-Fluorodeoxyglucose-position emission tomography suggested a likely malignant tumour and a biopsy was performed. Histopathological examination showed diffuse a large B cell lymphoma. The patient was treated with high-dose methotrexate (HD-MTX) and radiotherapy. Despite responding well to initial treatment, the patient relapsed, with lymphoma observed throughout the body. He died of pneumonia 18 months after the initial diagnosis. Facial pain is a symptom that is commonly managed in general practice. If symptoms do not improve, repeated imaging studies, including contrast MRI, is warranted. This is the first reported case of primary neurolymphomatosis (NL) of the trigeminal nerve associated with facial pain alone. Furthermore, HD-MTX and radiotherapy may be considered for the management of primary NL of a cranial nerve.

[Neurolymphomatosis due to enteropathy-associated T-cell lymphoma clinically diagnosed by FDG-PET/CT and subsequently confirmed by autopsy]

A 59-year-old man who complained of abdominal pain was referred to our hospital. Computed tomography (CT) revealed mesenteric lymph node swelling and intestinal perforation. Histopathological study of the resected ileum and lymph node demonstrated diffuse proliferation of medium-sized atypical lymphocytes. Immunohistochemistry results were positive for cluster of differentiation (CD) 3, CD8, and CD56 cells, negative for CD5 and CD4 cells, and negative for Epstein-Barr virus-encoded RNA-fluorescent in situ hybridization (EBER-FISH). It also revealed the expression of γδ T-cell receptors. On the basis of these findings, enteropathy-associated T-cell lymphoma (EATL) was diagnosed. Although the patient received two courses of cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (CHOP) and dexamethasone, etoposide, ifosfamide, and carboplatin (DeVIC) therapy, facial nerve and lower limb paralysis manifested. Magnetic resonance imaging (MRI) and lumbar puncture revealed central nervous system invasion of the EATL. Despite intrathecal chemotherapy and high-dose cytarabine therapy, the patient's neurological symptoms deteriorated. Fluorodeoxyglucose positron emission tomography (FDG-PET) /CT scan showed the accumulation of FDG along both median and sciatic nerves, and he was diagnosed with neurolymphomatosis (NL). He died on day 120 after admission. Autopsy specimens exhibited infiltration of lymphoma cells in the median and sciatic nerves. Although only one case of suspected NL in a patient with type 2 EATL has been previously reported, we clinically diagnosed NL using FDG-PET/CT and confirmed the diagnosis by autopsy. This case is valuable in terms of the pathological diagnosis of NL.

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.

Ocular involvement in neurolymphomatosis

Purpose

To describe the ophthalmic symptoms and histopathological findings in a case of primary neurolymphomatosis (NL).

Observations

A man in his 60s with a prior diagnosis of chronic inflammatory demyelinating polyneuropathy developed facial numbness, diplopia, drooling, and difficulty swallowing. Over a 3-month period, he developed total ptosis and ophthalmoplegia of the right eye with a dilated, non-reactive pupil considered secondary to cranial nerve III and VI palsies. His left pupil subsequently became non-reactive to light and accommodation, and extraocular motility of the left eye was partially limited in all directions of gaze without ptosis. Autopsy findings included primary NL, diffuse large B-cell lymphoma of activated B-cell subtype, involving right and left cranial nerves V, VI, IX, and X; spinal nerve roots; both femoral nerves; and extrascleral, intrascleral, and intraocular short and long posterior ciliary nerves with extension into the adjacent choroid of both eyes. No evidence of lymphoma was identified elsewhere in the body.

Conclusions and importance

Our patient is only the second histological demonstration of ciliary nerve involvement by NL, and the first, to our knowledge, of primary NL spreading secondarily from the ciliary nerves into the choroid. Our patient demonstrates that NL, though rare, should be included in the differential diagnosis of ocular cranial nerve palsies and ophthalmoplegia.

Neurolymphomatosis of the Brachial Plexus and its Branches: Case Series and Literature Review

BACKGROUND

Neurolymphomatosis is a process of neoplastic endoneurial invasion, most strongly associated with non-Hodgkin's lymphoma. It must be distinguished from paraneoplastic, metabolic, nutritional and treatment-related causes of neuropathy that are common in this patient population.

METHODS

This brief case series illustrates the protean manifestations of neurolymphomatosis of the brachial plexus, ranging from focal distal mononeuropathy to multifocal brachial plexopathy, either as the index manifestation of lymphoma or as a complication of relapsing disease.

RESULTS

Prominent asymmetry, pain and nodular involvement on neuroimaging may help distinguish neurolymphomatosis from paraneoplastic immune demyelinating radiculoneuropathy. MR neurography criteria for the diagnosis of neurolymphomatosis include hyperintensity on T2 and STIR sequences, focal and diffuse nerve enlargement with fascicular disorganization and gadolinium enhancement. No specific anatomical distribution within the brachial plexus has, however, been found to be characteristic. Fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging is the imaging modality with the highest sensitivity for detection of nodal or extranodal spread in lymphoma.

CONCLUSIONS

Brachial plexus neuropathy in neurolymphomatosis is highly protean in its distribution, semiology and relation to lymphoma staging. Dedicated MRI and PET-CT imaging are leading diagnostic modalities.

Cauda equina syndrome secondary to neurolymphomatosis: Case report and literature review

Neurolymphomatosis is a rare disorder characterised by infiltration of neoplastic lymphocytes into the peripheral nervous system. A wide variety of symptoms can manifest depending on its nature and location, making its diagnosis a real challenge. Treatment is based on methotrexate, although various chemotherapy regimens are currently available for patients with systemic disease. We present the case of a male patient with neurolymphomatosis of the cauda equina, together with a review of all cases published to date.

Diagnosis of secondary peripheral neurolymphomatosis: a multi-center experience

Here, we describe our experience with secondary neurolymphomatosis (NL) in non-Hodgkin lymphoma patients, with the emphasis on the diagnosis process. A retrospective chart review of 12 patients from 3 tertiary academic centers between January 2005 and December 2015 was conducted. Secondary NL was diagnosed within a median interval of 10 months (range 5-41 months) after initial diagnosis of NHL. Painful neuropathy was present in 66.7%, but the diagnosis of NL was delayed in nine out of 12 patients (75.0%) by median of 2 months. Diagnostic modalities included CSF analysis performed in nine patients (75.0%), electrodiagnostic studies in seven (58.3%), radiologic studies in all, and nerve biopsy in two (16.7%). The diagnostic yield was 100.0% (15/15) for FDG-PET/CT and 75.0% (9/12) for MRI. Our experience emphasizes the importance of clinical suspicion of NL in patients with previous history of NHL and selection of diagnostic modality with the greatest clinical utility.

Neurolymphomatosis of the peripheral nervous system: a case report and review of the literature

Neurolymphomatosis is a rare neurological syndrome in lymphomas. It is reported as infiltration of peripheral nerves by lymphoma. It is important to distinguish neurolymphomatosis from other types of neuropathies, particularly infectious and inflammatory conditions. However, it is difficult to isolate a cancer-related inflammatory vasculitis and mononeuritis multiplex without definitive histopathologic examination. In this report, we describe a case of non-Hodgkin's lymphoma involving the peroneal nerve and presenting as neurolymphomatosis.

Isolated sciatic neuropathy as an initial manifestation of a high grade B-cell lymphoma: A case report and literature review

Sciatic nerve neuropathy due to infiltrating of a high grade B-cell lymphoma is a very rare situation and has not often been reported. We report a case with a previous history of indolent lymphoma who presented with isolated sciatic nerve neuropathy and was found to have diffuse large B cell lymphoma involving the sciatic nerve. Although the current case is not a primary sciatic nerve lymphoma given the systematic involvement shown on MRI and PET/CT scan, the case represents a neurolymphomatosis of the sciatic nerve given the direct invasion of the lymphoma cells into the sciatic nerve. Due to the rarity of this condition, we subsequently reviewed related literatures.

Diagnostic utility of FDG-PET in neurolymphomatosis: report of five cases

Neurolymphomatosis (NL) is a rare condition involving the infiltration of lymphoma cells into the peripheral nervous system. NL can be primary or secondary in the setting of an unknown or known hematologic malignancy, respectively. Here, we report five cases in which F-18 2-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (F-18 FDG-PET/CT) had great value for diagnosing NL. Two cases were rare primary NL, and the other three were secondary NL. Clinical presentations were asymmetric sensorimotor disturbances in the extremities with or without involvement of cranial nerves. Furthermore, all patients experienced spontaneous pain in the face or affected extremities. Cerebrospinal fluid analysis was cytologically negative in two of five cases. Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) detected abnormalities in the cranial nerves, nerve roots, and cauda equina in all cases except case 1 and the recurrent stage of case 2. F-18 FDG-PET/CT showed clear visualization of almost all the lymphomatous involvement of peripheral nerves and other tissues in all patients. Furthermore, F-18 FDG-PET/CT detected abnormalities including asymptomatic lesions that were not detected with MRI, and also identified the appropriate lesion for diagnostic biopsy. However, as in case 3, the lesions in the left oculomotor nerve and the cauda equina were detected only with Gd-enhanced MRI, which has superior spatial resolution. In conclusion, F-18 FDG-PET/CT is a sensitive modality that can suggest the presence of malignancy and identify appropriate places for diagnostic biopsies. It is especially useful when combined with Gd-enhanced MRI, even in patients with primary NL that is usually difficult to diagnose.

Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence.

This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.

Various neurological symptoms by neurolymphomatosis as the initial presentation of primary testicular lymphoma

Neurological symptoms induced by the infiltration of malignant lymphoma into the nervous systems are subsumed under the term neurolymphomatosis (NL). Here, we report the case of a 30-year-old Japanese man with primary testicular lymphoma complicated, as seen in various neurological findings, by secondary NL prior to testicular swelling. Painless right scrotal enlargement was noticed more than 1 month after the appearance of neurological complications such as right upper extremity numbness, dysarthria, facial palsy, and diplopia. Proactive investigation and biopsies of extranodal sites at high risk of central nervous system infiltration of malignant lymphoma, such as the testes, should be considered when secondary NL is suspected based on imaging findings.