The role of 18F-FDG PET/CT in Neurolymphomatosis: A Comprehensive Imaging Approach.

Neurolymphomatosis (NL) is an uncommon and rare neurologic disorder characterised by extranodal lymphoma, where the tumour cells invade the cranial nerves, nerve plexus, nerve root, spinal nerve roots, trunk nerves or peripheral nerves. MRI is the modality of choice, but is often challenging in detection of early recurrence, assessing residual disease and response evaluation. 18FFDG PET/CT has superior diagnostic performance compared with body CT in the evaluation of NL. 18F-FDG PET-CT is helpful in evaluation of disease extent and potential to guide biopsy. 18F-FDG PETCT is a highly sensitive technique for early localisation of NL than MRI or CT alone. Besides diagnostic and prognostic value in NL, it might be very helpful in response assessment.

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.

Nerve biopsy in T-cell lymphoma with neurolymphomatosis: where and when.

Peripheral T-cell lymphomas are rare heterogeneous haematological malignancies that may also involve peripheral nerves in a very small subset of cases. We report a patient with a diagnostically challenging cutaneous T-cell lymphoma and multifocal mononeuropathies in whom a targeted nerve biopsy identified lymphomatous infiltration of nerves and expedited combination treatment with chemotherapy and an autologous stem cell transplant. She showed an excellent response with a complete metabolic response on positron emission tomography imaging and significant clinical improvement, maintained 5 years post-treatment.

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.

Chimeric Antigen Receptor T-Cell Therapy of Neurolymphomatosis Monitored by FDG PET/CT.

ABSTRACT: 18 F-FDG PET/CT was performed to evaluate possible recurrent B-cell lymphoblastic lymphoma in a 34-year-old man. The images showed multiple foci of increased activity in the nerve root and peripheral nerve. A biopsy confirmed the diagnosis of neurolymphomatosis. After receiving chemotherapy, PET/CT showed progressive disease. The patient subsequently received the CD-19 chimeric antigen receptor T-cell therapy. A follow-up PET/CT acquired 30 days after chimeric antigen receptor T-cell therapy revealed no abnormal FDG activity.

Isolated Primary Neurolymphomatosis in the Right Brachial Plexus Proven by Partial Nerve Biopsy.

INTRODUCTION: Isolated primary neurolymphomatosis is a rare manifestation of lymphoma, which is challenging to diagnose as there is only involvement of the nervous system, and nerve biopsy is not frequently pursued due to the high risk of irreversible complications. CASE REPORT: We present a case of isolated primary neurolymphomatosis of diffuse large B-cell lymphoma restricted to only the right brachial plexus and right axillary nerve. The clinical course has been indolent for several years. The initial examination, including MRI and the cerebrospinal fluid study, did not yield any evidence of malignancy. Eventually, due to the patient's symptom progression and the follow-up imaging findings, we conducted a partial nerve biopsy of the brachial plexus to confirm the malignancy. His neurological symptoms did not further deteriorate post-biopsy. CONCLUSION: Isolated primary neurolymphomatosis with an indolent course is rare and challenging to diagnose. Serial MRI and fluorodeoxyglucose-positron emission tomography reveal clues for tumor involvement. Partial nerve biopsy or targeted fascicular nerve biopsy could be an alternative for achieving a pathologic diagnosis.

18F-FDG PET/CT and clinicopathological characteristics of neurolymphomatosis in lymphoma patients.

OBJECTIVE: Neurolymphomatosis (NL) is a rare but serious manifestation defined as invasion of peripheral nervous system by malignant lymphocytes. Thus, this study investigated fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and clinicopathological characteristics of NL in lymphoma patients. SUBJECTS AND METHODS: Clinicopathological and 18F-FDG PET/CT findings and treatment regimens were retrospectively investigated in 20 lymphoma patients with NL, and analyzed their correlation with progression-free survival (PFS) and overall survival (OS). RESULTS: These 20 lymphoma patients (11 males, 9 females; median age, 49 years) included 10 primary and 10 secondary NL patients. Non-Hodgkin's lymphoma (NHL) was noted in 19 patients, B-cell NHL was associated with 18 cases, and diffuse large B-cell lymphoma was the most common. Notably, 18 patients were aggressive lymphoma while 2 were indolent lymphoma. The affected neural structures included nerve roots (n=17), peripheral nerves (n=3), cranial nerves (n=3), and neural plexus (n=2). Fluorine-18-FDG was avid in all cases, and the median maximum standardized uptake value (SUVmax) of neural and all lesions was 12.2 (range, 3.3-25.6) and 15.0 (range, 4.4-34.2), respectively. The median PFS and OS of all patients were 9.3 and 14.3 months. The 12-month OS rate of 18 patients with aggressive lymphoma receiving intrathecal chemotherapy/autologous stem cell transplants (IT chem/ASCT) was significantly higher than who did not (64.8% vs 15.9%). CONCLUSION: The majority of NL occurred in patients with aggressive lymphoma, of which B-cell NHL were the predominant subtypes. Fluorine-18-FDG PET/CT imaging of NL was mainly characterized by intense glucose accumulation alongside peripheral nerves, and IT chem/ASCT was suggested to improve the outcomes of NL.

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.

Lumbosacral Plexus Neurolymphomatosis: A Typical 18FDG PET/CT Pattern to Recognize.

ABSTRACT: A 79-year-old man anteriorly treated for primary central nervous system diffuse large B-cell lymphoma with MRI complete response after immunochemotherapy was referred 1 year later for 18FDG PET/CT because of right persistent lombosciatic radicular pain for 6 months with negative medullary and spine MRI and negative cerebrospinal fluid cytology. Linearly intense uptake was observed in several roots of lumbosacral plexus, highly suggestive of peripheral neurolymphomatosis relapse. No specific treatment was engaged because of rapid decrease of performance status leading to death.

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.

FDG PET/CT in Neurolymphomatosis.

Online supplemental material is available for this article.

Understanding the Pathognomonic Tumefactive Appearance of Neurolymphomatosis: A Unifying Theory of Neurolymphoma.

BACKGROUND: The diagnosis of peripheral neurolymphomatosis (NL) is difficult and often delayed, because patients can have isolated, nonspecific nerve symptoms. Magnetic resonance imaging will usually show nonspecific findings of enlarged, contrast-enhancing nerves. We aimed to elucidate the mechanism behind an imaging finding we believe is pathognomonic of NL and likely of other hematologic diseases with peripheral nerve involvement. METHODS: We reviewed the imaging studies of a previously reported cohort of patients, in addition to those from more recent patients, all with tumefactive NL, in which enlarged nerve bundles were surrounded by tumor. We reviewed the demographic data, clinical data (e.g., primary or secondary disease, biopsy-proven diagnosis), and imaging findings (e.g., tumefactive appearance, primary involved nerve, location of epicenter of tumefactive appearance, vascular involvement). RESULTS: All cases showed a maximum tumefactive appearance at branch or junction points, with a gradual decrease of this appearance moving proximally and distally from the epicenter in a "crescendo-decrescendo" pattern. We have described this as a phasic mechanism with 3 phases: malignant cells fill the intraneural space; extrude at a weak spot of the nerve, which often occurs at a branch or junction point; and then expand and fill the subparaneurial space, creating the grossly tumefactive appearance with proximal and distal spread. CONCLUSIONS: We have presented a novel, unifying theory explaining the pathognomonic tumefactive appearance of NL. Our theory offers the first rational explanation for the radiological appearance of NL with peripheral nerve involvement. We believe that with earlier recognition of NL on imaging studies, patients will be able to receive an earlier diagnosis and undergo earlier treatment.

Circumdural extension of perineural spread leading to bilateral disease in neurolymphomatosis.

INTRODUCTION: Patients with neurolymphomatosis (NL) often present with one primarily symptomatic limb but can be found to have bilateral upper or bilateral lower limb disease during workup. We sought to explain the finding of bilateral disease and understand if there was a connection to the initial, symptomatic side of disease. METHODS: We reviewed imaging studies of patients with bilateral upper or bilateral lower limb disease from a previously published cohort from our institution, as well as more recent patients seen at our institution. We reviewed demographics (sex and age), clinical data (primary or secondary disease and biopsy-proven diagnosis), and imaging findings (primary involved nerve, contralateral nerve(s) affected, and location of circumdural extension). RESULTS: We identified 8 cases with evidence of bilateral disease out of 22 cases of tumefactive NL. All eight cases were found to have circumdural extension of disease to the corresponding contralateral nerve. CONCLUSION: We describe the pathomechanism of spread in our cases of bilateral upper or bilateral lower limb disease, where NL spreads along a dominant nerve toward the spinal canal and moves circumdurally to affect the corresponding contralateral nerve. We believe this information is useful to further understand the spread of NL, as well as offering important diagnostic and prognostic information for patients.

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.

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.