F-18 FDG PET/CT Findings of a Case of Sacral Nerve Root Neurolymphomatosis That Occurred During Chemotherapy

Neoplastic nerve lesions

Though metastasis and malignant infiltration of the peripheral nervous system is relatively rare, physicians should have a familiarity with their presentations to allow for prompt diagnosis and initiation of treatment. This article will review the clinical presentations, diagnostic evaluation, and treatment of neoplastic involvement of the cranial nerves, nerve roots, peripheral nerves, and muscle. Due to the proximity of the neural structure traversing the skull base, metastasis to this region results in distinctive syndromes, most often associated with breast, lung, and prostate cancer. Metastatic involvement of the nerve roots is uncommon, apart from leptomeningeal carcinomatosis and bony metastasis with resultant nerve root damage, and is characterized by significant pain, weakness, and numbness of an extremity. Neoplasms may metastasize or infiltrate the brachial and lumbosacral plexuses resulting in progressive and painful sensory and motor deficits. Differentiating neoplastic involvement from radiation-induced injury is of paramount importance as it dictates treatment and prognosis. Neurolymphomatosis, due to malignant lymphocytic infiltration of the cranial nerves, nerve roots, plexuses, and peripheral nerves, deserves special attention given its myriad presentations, often mimicking acquired demyelinating neuropathies.

Neurolymphomatosis of the median nerve, optic nerve, L4 spinal nerve root and cauda equina in patients with B-cell malignancies: a case series

BACKGROUND

Neurolymphomatosis is rare. Neoplastic lymphocytes are seen to invade nerves (cranial or peripheral), nerve roots or other related structures in patients with hematological malignancy. It is a separate entity from central nervous system lymphoma. Neurolymphomatosis has most commonly been described in association with B-cell non-Hodgkin lymphoma. Neurolymphomatosis in the context of Burkitt lymphoma and the post-renal transplant setting has not been described before.

CASE REPORTS

We report for the first time in the Arabian Gulf countries and nearby Arab states four cases of neurolymphomatosis (one Asian, and the other 3 are from Arabic nationals) occurring between 2012 and 2017 involving the median nerve, optic nerve, nerve root and cauda equina in patients with Burkitt lymphoma, Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia and diffuse large B-cell lymphoma.

CONCLUSIONS

Neurolymphomatosis is rare and can be difficult to diagnose by biopsy but reliably confirmed by a combined imaging approach. Prior treatment with high-dose dexamethasone might suppress 18F-fluorodeoxyglucose (FDG) activity and decrease the sensitivity of positron emission tomography/computed tomography (PET/CT). The prognosis is generally poor but using high-dose methotrexate as well as high-dose chemotherapy and autologous stem cell transplantation may be an effective way to treat 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.

A Unique Case of Erdheim-Chester Disease With Cervical and Lumbosacral Nerve Involvement: FDG PET/CT Finding

Cervical and lumbosacral nerve roots and plexus involvement in Erdheim-Chester disease (ECD) is rare. A 50-year-old man with progressive edema in bilateral lower extremities, numbness, weakness, and muscle atrophy of upper limb for 2 years had been misdiagnosed of neuritis or cervical spondylosis until he presented bone pain. In addition to bilateral symmetric involvement in long bones, bilateral hypermetabolism in cervical and lumbosacral nerve roots was found by FDG PET/CT scan. ECD was diagnosed by bone biopsy. This case reported the rare peripheral neural involvement and highlighted the advantage of FDG PET/CT scan in evaluating the multisystem involvement of ECD.

Diagnostic Yield of FDG-PET/CT, MRI, and CSF Cytology in Non-Biopsiable Neurolymphomatosis as a Heralding Sign of Recurrent Non-Hodgkin's Lymphoma

Neurolymphomatosis (NL) is a rare condition associated with lymphomas in which various structures of the nervous system are infiltrated by malignant lymphocytes. Rarely, it may be the presenting feature of recurrence of lymphoma otherwise deemed to be in remission. It is crucial, as is the case with all types of nodal or visceral involvement of lymphoma, to identify the disease early and initiate treatment with chemotherapy and/or radiation therapy. Positron emission tomography-computed tomography (PET-CT) has been shown to be a sensitive modality for staging, restaging, biopsy guidance, therapy response assessment, and surveillance for recurrence of lymphoma. Magnetic resonance imaging (MRI) is another useful imaging modality, which, along with PET/CT, compliment cerebrospinal spinal fluid (CSF) cytology and electromyography (EMG) in the diagnosis of NL. Performing nerve biopsies to confirm neurolymphomatosis can be challenging and with associated morbidity. The case presented herein illustrates the practical usefulness of these tests in detecting NL as a heralding feature of lymphoma recurrence, especially in the absence of histopathologic correlation.

Secondary neurolymphomatosis detected by whole-body diffusion-weighted magnetic resonance imaging: a case report

Neurolymphomatosis (NL) is a rare clinical entity defined as peripheral nervous system infiltration by lymphoma. The diagnosis is difficult and often elusive. Whole-body diffusion-weighted magnetic resonance imaging (DW MRI) was developed to enhance the detection of vaguely delineated tumors. Here, we describe the case of a 71-year-old male with secondary NL of diffuse large B-cell lymphoma (DLBCL) that was successfully detected by whole-body DW MRI. The patient was diagnosed with DLBCL extending from the ethmoidal sinus to the nasal cavity, orbital cavity, and anterior cranial fossa. Although he was administered R-THP-COP chemotherapy and the tumor remarkably decreased in size, he developed painful paresthesia and weakness in the left upper and bilateral lower extremities during treatment. Because lymphoma cells were detected in his spinal fluid, high-dose methotrexate (MTX) and weekly intrathecal MTX and cytarabine injections were administered. Test results for lymphoma cells in the spinal fluid became negative ; however, the neurological disorders progressed. Whole-body DW MRI was performed as whole-body screening and could localize NL at the left cervical and bilateral lumbar nerve roots. Both cervical spine plain MRI and enhanced computed tomography performed around the same time could not detect the cervical lesion. Our case report suggests that whole-body DW MRI is a useful diagnostic imaging procedure, especially as whole-body screening in facilities where PET/CT is not available.

Neurolymphomatosis as a late relapse of non-Hodgkin's lymphoma detected by 18F-FDG PET/CT: a case report

Neurolymphomatosis is a rare condition defined as an infiltration of nerves, nerve roots or nervous plexuses by haematological malignancy. Its diagnosis may sometimes be difficult with conventional imaging techniques. This paper aims to emphasize the importance of this entity and the role of (18)F-FDG PET/CT in this indication. We present the case of a 53-year-old male who complained of sharp pain in his right hip and right leg paresthesia after 2 years of complete remission from Non-Hodgkin's lymphoma. Physical examination and CT scan were negative and the lumbar MRI showed protrusion of L5-S1 disc. Physiotherapy, nonsteroid antiinflammatory drugs and steroids were inefficient. PET/CT was performed four months after the onset of the symptoms, revealing focal FDG uptake in the right S1 nerve root and linear FDG uptake along the right sacral plexus suggesting relapse. This was confirmed by histology.

Diagnosis and management of neurolymphomatosis

Invasion of cranial nerves and peripheral nerve roots, plexus, or nerves by non-Hodgkin lymphoma is denoted as neurolymphomatosis (NL). Four clinical patterns are recognized. Most commonly, NL presents as a painful polyneuropathy or polyradiculopathy, followed by cranial neuropathy, painless polyneuropathy, and peripheral mononeuropathy. Diagnosis of NL is challenging and requires integration of clinical information, imaging findings, and histopathologic examination of involved nerves or nonneural tissue and cerebrospinal fluid analysis. In the rare cases of primary NL, the diagnosis is often delayed. Successful therapy is contingent upon recognition of the disease and its exact neuroanatomic localization without delay. Treatment options include systemic chemotherapy and localized irradiation of bulky disease sites. Concomitant involvement of cerebrospinal fluid and systemic disease sites requires more complex regimens.

Neurolymphomatosis diagnosed by (18)F-FDG PET-CT

Neurolymphomatosis is defined as infiltration of the nervous system by hematological malignancy and is difficult to diagnose. We report a case of a 57-year-old man, treated for small B-cell non-Hodgkin lymphoma, presenting with sensorimotor impairment of the lower limbs, which started 6 years after diagnosis. He was treated with chemotherapy, after which, the symptoms disappeared. After 7 months, he developed sensorimotor impairment of both upper limbs. MRI of the brachial plexus showed no abnormalities. F-FDG PET-CT showed increased uptake at the brachial plexus and nerves, suggesting neurolymphomatosis. Confirmatory biopsy revealed conversion of the malignancy to diffuse large B-cell lymphoma.