Value of nerve biopsy in patients with latent malignant hemopathy and peripheral neuropathy: a case series

Neurosurgical Intervention for Nerve and Muscle Biopsies

(1) Background: Neurologic and musculoskeletal diseases represent a considerable portion of the underlying etiologies responsible for the widely prevalent symptoms of pain, weakness, numbness, and paresthesia. Because of the subjective and often nonspecific nature of these symptoms, different diagnostic modalities have been explored and utilized. (2) Methods: Literature review. (3) Results: Nerve and muscle biopsy remains the gold standard for diagnosing many of the responsible neurological and musculoskeletal conditions. However, the need for invasive tissue sampling is diminishing as more investigations explore alternative diagnostic modalities. Because of this, it is important to explore the current role of neurosurgical intervention for nerve and muscle biopsies and its current relevance in the diagnostic landscape of neurological and musculoskeletal disorders. With consideration of the role of nerve and muscle biopsy, it is also important to explore innovations and emerging techniques for conducting these procedures. This review explores the indications and emerging techniques for neurological intervention for nerve and muscle biopsies. (4) Conclusions: The role of neurosurgical intervention for nerve and muscle biopsy remains relevant in diagnosing many neurological and musculoskeletal disorders. Biopsy is especially relevant as a supportive point of evidence for diagnosis in atypical cases. Additionally, emerging techniques have been explored to guide diagnostics and biopsy, conduct less invasive biopsies, and reduce risks of worsening neurologic function and other symptoms secondary to biopsy.

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.

Association Between Incident Cancer and Guillain-Barré Syndrome Development: A Nationwide Case-Control Study

BACKGROUND AND OBJECTIVES

Cancer may increase the risk of developing Guillain-Barré syndrome (GBS) due to molecular mimicry or immunosuppression, but the exact relationship is unclear. We aimed to determine the association between incident cancer and the following risk of GBS development.

METHODS

We conducted a nationwide population-based case-control study of all patients with first-time hospital-diagnosed GBS in Denmark between 1987 and 2016 and 10 age, sex and index date-matched population controls per case. We identified incident cancer diagnoses between six months prior to and two months after the GBS index date. We used conditional logistic regression to compute ORs as a measure of relative risk and performed stratified analyses to assess the impact of cancer on GBS risk in strata of calendar-periods, sex and age. In sensitivity analyses, to assess any potential risk of survival bias induced by including cancer diagnoses potentially made after GBS diagnosis, we examined incident cancers in both a broader exposure window (one year before to three months after GBS index date) and a narrower window (six months to one month before the GBS index date).

RESULTS

Of the 2,414 patients with GBS and 23,909 controls included, 49 cases (2.0%) and 138 controls (0.6%) had a recent cancer diagnosis, respectively, yielding a matched odds ratio (OR) of 3.6 (95% confidence interval (CI), 2.6- 5.1) for GBS associated with cancer. Stratification by calendar time, gender and age showed robust results for the association between cancer and GBS, with no major variations. Broadening and narrowing the exposure window produced slightly weakened associations of OR, 2.4 (95% CI, 1.8-3.3) and OR, 2.5 (95% CI, 1.5-4.1), respectively. The GBS ORs were highest for cancers of the lymphatic and hematopoietic tissue (OR, 7.2; 95% CI, 2.9-18.0), respiratory tract (OR, 5.6; 95% CI, 2.7-11.9), prostate and other male genital organ (OR, 5.0; 95% CI, 2.1-11.6) and breast cancer (OR, 5.0; 95% CI, 1.7-14.5).

DISCUSSION

In this large nationwide epidemiologic study, incident cancer was associated with a markedly increased risk of subsequent GBS development. The results suggest that yet unidentified factors present in several types of cancer drive this association.

CIDP and hemopathies, an underestimated association

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated and treatable disease that may be associated with various systemic conditions. Our objective is to describe the clinical, electrophysiological and pathological data of a series of patients with both CIDP and hemopathy. In this retrospective study, we analyzed 21 patients with CIDP and various hemopathies (malignant or not), consecutively observed for almost five years. In this particular context (with a risk of neurological complications of the hemopathy), a nerve biopsy was taken from each patient (after written consent). All the patients fulfilled the EAN/PNS electrodiagnostic criteria (2021) of CIDP: 16 with 'CIDP' and 2 with 'possible CIDP' (no data for 3 patients). For each patient, pathological analysis of nerve biopsy was compatible with the diagnosis of CIDP, and there was no evidence for hematological complication of the peripheral nervous system. In cases of peripheral neuropathy and malignant hemopathy, the possibility that the peripheral neuropathy is CIDP should not be overlooked because CIDP is clearly accessible to appropriate therapies, with high potential for a positive clinical response. If the diagnosis of CIDP is usually suspected clinically and electrophysiologically, it should be confirmed by pathological study (nerve biopsy) in certain cases. The management of such patients benefits from the collaboration of neurologists, hematologists and oncologists.

Nerve biopsy in acquired neuropathies

A diagnosis of neuropathy can typically be determined through clinical assessment and focused investigation. With technological advances, including significant progress in genomics, the role of nerve biopsy has receded over recent years. However, making a specific and, in some cases, tissue-based diagnosis is essential across a wide array of potentially treatable acquired peripheral neuropathies. When laboratory investigations do not suggest a definitive diagnosis, nerve biopsy remains the final step to ascertain the etiology of the disease. The present review highlights the utility of nerve biopsy in confirming a diagnosis, while further illustrating the importance of a tissue-based diagnosis in relation to treatment strategies, particularly when linked to long-term immunosuppressive therapies.

Nerve biopsy: Current indications and decision tools

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Paraproteinaemic neuropathy: MGUS and beyond

Paraproteinaemic neuropathies comprise a heterogeneous group of neuro-haematological conditions with some distinct neurological, haematological and systemic phenotypes. The spectrum of disease varies from mild to severe, indolent to rapidly progressive and from small fibre sensory involvement to dramatic sensorimotor deficits. The haematological association may be overlooked, resulting in delayed treatment, disability, impaired quality of life and increased mortality. However, the presence of an irrelevant benign paraprotein can sometimes lead to inappropriate treatment. In this review, we outline our practical approach to paraproteinaemic disorders, discuss the utility and limitations of diagnostic tests and the distinctive clinical phenotypes and touch on the complex multidisciplinary management approaches.

Monoclonal Gammopathies of 'Neurological Significance': Paraproteinemic Neuropathies

OBJECTIVES

To study the clinical profile and outcomes of patients with paraproteinemic neuropathy (PPN) and to explore the utility of nerve conduction studies (NCSs) to differentiate between the demyelinating subtypes.

METHODS

We did a retrospective analysis of patients diagnosed with PPN between January 2010 and December 2019 in an inpatient setting. The study population consisted of patients above 16 years of age presenting with clinical features suggestive of chronic peripheral neuropathy and on evaluation was found to have PPN.

RESULTS

A total of 74 patients were identified. The patients were predominantly in the 6th decade, and the majority were males. The subtypes of PPN were monoclonal gammopathy of undetermined significance (MGUS) (45.9%), POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes) (24.3%), solitary plasmacytoma (17.6%), multiple myeloma (8.1%), and AL amyloidosis (4.1%). There are specific features on NCS which can help in identifying POEMS syndrome and IgM MGUS. The majority of patients with PPN tend to stabilize or improve with treatment; however, many have a severe residual disability. New terminology and classification of these entities as 'monoclonal gammopathies of neurological significance' can aid in early diagnosis and the development of effective treatment, to prevent residual disability.

CONCLUSION

PPN has a heterogeneous spectrum of clinical, biochemical, and electrophysiological features. NCS can help distinguish POEMS syndrome and IgM MGUS from other demyelinating subtypes.

The Wide Spectrum of Pathophysiologic Mechanisms of Paraproteinemic Neuropathy

Monoclonal gammopathy is encountered quite frequently in the general population. This type of hematologic abnormality may be mild, referred to as monoclonal gammopathy of undetermined significance or related to different types of hematologic malignancies. The association of a peripheral neuropathy with monoclonal gammopathy is also fairly common, and hemopathy may be discovered in an investigation of peripheral neuropathy. In such a situation, it is essential to determine the exact nature of the hematologic process in order not to miss a malignant disease and thus initiate the appropriate treatment (in conjunction with hematologists and oncologists). In this respect, nerve biopsy (discussed on a case-by-case basis) is of great value in the management of such patients. We therefore propose to present the objectives and main interests of nerve biopsy in this situation.

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.

Patient With 2 Hematologic Malignancies Presenting as Neurolymphomatosis

Peripheral nervous system damage from hematologic malignancies is related to neoplastic cells infiltration of peripheral nerves or to monoclonal antibody production cross-reacting with peripheral nerves' antigens. Neurolymphomatosis (NL), a rare manifestation of hematologic malignancies, occurs when malignant cells invade the peripheral nerves leading to various manifestations. Here, we report a case of NL with 2 hematologic malignancies in a 79-year-old woman presenting with lower extremity pain/weakness. Investigation revealed anemia, IgM kappa monoclonal gammopathy, and elevated anti-MAG titer. Electrodiagnostic studies were consistent with mononeuropathy multiplex while imaging suggested malignancy in her ovaries and right S1 nerve root. Bone marrow and ovarian biopsies revealed chronic myelomonocytic leukemia, Waldenstrom macroglobulinemia, and diffuse large B-cell lymphoma. She received standard chemotherapy resulting in radiographic resolution of disease and symptomatic relief. NL can precede the diagnosis of hematologic malignancy but its symptoms are not easily identifiable, whereas management depends on the treatment of the underlying tumor.

Monoclonal gammopathy of undeterminated significance and endoneurial IgG deposition: A case report

BACKGROUND

Monoclonal gammopathy of undeterminated significance is the most common form of plasma cell dyscrasia, usually considered as benign. In rare cases it may have a malignant course, sometimes limited to an organ such as peripheral nerves.

METHODS

We describe clinical, electrophysiological and pathological findings in a patient presenting a immunoglobulin G (IgG) paraproteinemic polyneuropathy clinically mimicking a chronic inflammatory demyelinating polyneuropathy.

RESULTS

Immuno-electron microscopy (immune-EM) demonstrated that the widenings of the myelin lamellae resulted from the infiltration of IgG between a significant number of myelin lamellae (with absence of inflammatory cells in the epineurium, endoneurium, and perineurium, and the lack signs of vasculitis). This patient was finally treated successfully with lenalidomide then mycophenolate mofetil.

CONCLUSIONS

In polyneuropathies associated to a monoclonal gammopathy, a nerve biopsy may clinch the diagnosis. Immuno-EM may be required to determine the role of the pathological immunoglobulin in the destruction of the peripheral nerve parenchyma. Diagnosis of such a direct involvement of peripheral nerve can endorse more aggressive treatment of real efficiency.