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

Primary peripheral nerve lymphoma: a case report and literature review

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

Sciatic diffuse large B-cell lymphoma with treatment response to CHOP and radiotherapy

Neurolymphomatosis is an uncommon presentation of lymphoma caused by the infiltration of the peripheral nervous system by lymphoid cells. Here, we describe a case of neurolymphomatosis of the sciatic nerve in 41-year-old woman, which presented by acute onset pain and progress to paresthesia and weakness. Magnetic resonance imaging (MRI) revealed lobulated mass involving the right sciatic nerve with central necrosis and mild surrounding edema, which was isointense on T1-weighted images, hyperintense on short tau inversion recovery (STIR). Positron emission tomography and computed tomography (PET-CT) showed centrally necrotic mass with avid fluorodeoxyglucose (FDG) uptake in the right sciatic nerve. Partial resection of the tumor was done, and the diagnosis of the diffuse large B-cell lymphoma was made and confirmed by bone marrow biopsy. Patient was treated with R-CHOP chemotherapy (regimen consisting of cyclophosphamide, doxorubicin, prednisone, rituximab, and vincristine) and radiotherapy.

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.

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.

Primary lymphoma of the medial cutaneous nerve of the forearm: the first case in a pure sensory nerve of the upper limb

Primary lymphoma of the peripheral nerve is very rare and occurs most frequently in sciatic nerves. We describe the first patient reported in literature with a primary lymphoma in a pure sensory peripheral nerve of the upper limb. A woman in her 40s, with painful swelling and dysaesthesias in her left forearm in the past 3 months, was presented at our unit. Clinical MRI and ultrasound findings revealed a lesion that showed signs of a peripheral nerve sheath tumour. After complete excision, morpho-pathological evaluation revealed a primary B-cell lymphoma. The patient underwent radiotherapy and at the last follow-up there were no signs of residual pathology. Peripheral neuropathy may be caused by a lymphoma involving the nerve. Hand surgeons have to distinguish primary lymphoma of the peripheral nerves from schwannoma for their different clinical behaviour.

Imaging of non-neurogenic peripheral nerve malignancy-a case series and systematic review

OBJECTIVE

To evaluate the frequency, clinico-pathologic and imaging features of malignant tumors in peripheral nerves which are of non-neurogenic origin (non-neurogenic peripheral nerve malignancy-PNM).

MATERIALS AND METHODS

We retrospectively reviewed our pathology database for malignant peripheral nerve tumors from 07/2014-07/2019 and performed a systematic review. Exclusion criteria were malignant peripheral nerve sheath tumor (MPNST). Clinico-pathologic and imaging features, apparent diffusion coefficient (ADC_min), and standard uptake values (SUV_max) are reported.

RESULTS

After exclusion of all neurogenic tumors (benign = 196, MPNST = 57), our search yielded 19 non-neurogenic PNMs (7%, n = 19/272), due to primary intraneural malignancy (16%, n = 3/19) and secondary perineural invasion from an adjacent malignancy (16%, n = 3/19) or metastatic disease (63%, n = 12/19). Non-neurogenic PNMs were located in the lumbosacral plexus/sciatic nerves (47%, n = 9/19), brachial plexus (32%, n = 6/19), femoral nerve (5%, n = 1/19), tibial nerve (5%, n = 1/19), ulnar nerve (5%, n = 1/19), and radial nerve (5%, n = 1/19). On MRI (n = 14/19), non-neurogenic PNM tended to be small (< 5 cm, n = 10/14), isointense to muscle on T1-W (n = 14/14), hyperintense on T2-WI (n = 12/14), with enhancement (n = 12/12), low ADC_min (0.5-0.7 × 10-3 mm²/s), and variable metabolic activity (SUV_max range 2.1-13.1). A target sign was absent (n = 14/14) and fascicular sign was rarely present (n = 3/14). Systematic review revealed 89 cases of non-neurogenic PNM.

CONCLUSION

Non-neurogenic PNMs account for 7% of PNT in our series and occur due to metastases and primary intraneural malignancy. Although non-neurogenic PNMs exhibit a non-specific MRI appearance, they lack typical signs of neurogenic tumors such as the target sign. Quantitative imaging features identified by DWI (low ADC) and F¹⁸-FDG PET/CT (high SUV) may be helpful clues to the diagnosis.

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.

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.

Primary B lymphoma tumor of the ulnar nerve. Case report

Primary lymphoma of a peripheral nerve is a very rare condition with only a few cases reported in the medical literature. Primary lymphoma of a peripheral nerve in the upper extremity was reported in only four cases in the English and French literature. We present a case of a 54-year-old man, in good health, without other medical conditions, who came to our unit complaining of paraesthesia in the ulnar territory of the hand. MRI investigation showed a mass situated in the ulnar nerve sheaths, in the lower third of the arm. Surgical exploration and excision were performed. Morphopathological results revealed a very uncommon tumor, a large B cell diffuse non-Hodgkin lymphoma, the second primary ulnar nerve lymphoma presented in the literature.

Early diagnosis and a better understanding of the pathogenesis of these tumors may change medical and surgical strategies, with further enhancement of survival rates.

Rare finding in peripheral nerve surgery: an unicentric Castleman disease presenting as median nerve tumour

A 51 year old man presented with progressive swelling in the upper arm. MRI revealed a solitary mass extending from the median nerve. Intraoperative finding was a tumour extending within the nerve in its proximal fibres. The histological result showed a Castleman disease.

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.