18F-FDG PET/CT/MRI Fusion Images Showing Cranial and Peripheral Nerve Involvement in Neurolymphomatosis.

We report a 56-year-old female patient with non-Hodgkin's diffuse large B cell lymphoma (NHL) who, on magnetic resonance imaging (MRI) with a T1 weighted and gadolinium-enhanced imaging, was found to have thickening and infiltration in 75% of peripheral nerves of the patient and enlargements of cranial nerves, possibly related to lymphomatous infiltration. Subsequent positron emission tomography/computed tomography (PET/CT) using 18F-labeled 2-deoxy-2-fluoro-d-glucose (18F-FDG) showed widespread active involvement of the cervical plexus, bilateral peripheral nerves, right femoral nerve, the parasellar region of the skull, and marked hypermetabolism in the left trigeminal ganglia. This case re-emphasizes that while CT and MRI provide anatomical details, 18F-FDG PET/CT images better delineate the metabolic activity of neurolymphomatosis (NL) in the peripheral and central nervous system.

A 56-Year-Old Female Patient With Non-Hodgkin's Diffuse Large B-Cell Lymphoma (Nhl) Presenting With Hoarseness, Nasal Obstruction, Left Facial Paralysis, and Numbness Was Confirmed to Have Aseptic Meningitis on Lumbar Puncture Examination. Treatment Started for Meningitis and Chemotherapy for Lymphoma. the Patient Continued to Show Clinical and Neurological Deterioration With Confused State and a Decreased Level of Consciousness. Gadolinium-Enhanced T1 Weighted Magnetic Resonance Imaging (Mri) Image Showed Thickening and Infiltration in 75% of Peripheral Nerves of the Patient and Enlargements of Cranial Nerves, Possibly Related to Lymphomatous Infiltration. Subsequently Patient Was Subjected to18 f-Labeled 2-Deoxy-2-Fluoro-d-Glucose (18 f-Fdg) Positron Emission Tomography/computed Tomography (Pet/ct) [Figure 1].

Figure 1

18F-FDG PET/CT/MRI fusion showed thickening and infiltration in 75% of peripheral nerves and enlargements of cranial nerves in the parasellar region of the skull with marked hypermetabolism in the left trigeminal ganglia (A), possibly related to lymphomatous infiltration. 18F-FDG PET/CT showing widespread active involvement of the cervical plexus, bilateral peripheral nerves, and Right femoral nerve (B) with a conspicuous lymphomatous infiltration through the lateral foramina in the lumbar spine (C). (R, Right; L, left; A, anterior; P, posterior)

Neurolymphomatosis (NL) is a rare disorder characterized by infiltration of nerves, aggressive subtypes of NHL or leukemia.[12] It is related to peripheral nervous system infiltration by lymphomatous lymphocytes cells of cranial nerves, trunk nerves, nerve roots, and plexus in the setting of a hematologic malignancy.[3] Most commonly, NL presents as a painful polyneuropathy or polyradiculopathy, followed by cranial neuropathy, painless polyneuropathy, and peripheral mononeuropathy.[4] Diagnosis requires a high index of clinical suspicion and histopathologic confirmation of an involved nerve by biopsy, or at autopsy. Brain and spinal nerves MRI, and CT of the trunk are essential in providing an overview of the structural involvement, but in some cases, just anatomic images can be ineffective in showing the active malignancy.[5] In this setting, PET/CT is being highly recommended to evaluate the extent of disease throughout the body complementing the anatomical images.[678] This case evidences that 18F-FDG PET/CT images better delineated the metabolic activity of NL in the peripheral and central nervous system.

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