Primary cauda equina lymphoma confirmed by autopsy: A case report

Compared with those involving the central nervous system, lymphomas involving the peripheral nervous system, namely neurolymphomatosis, are extremely rare. Neurolymphomatosis is classified as primary or secondary; the former is much rarer than the latter. Herein, we present an autopsied case of primary cauda equina lymphoma (PCEL), a type of primary neurolymphomatosis, with a literature review of autopsied cases of PCEL as well as primary neurolymphomatosis other than PCEL (non-PCEL primary neurolymphomatosis). A 70-year-old woman presented with difficulty walking, followed by paraplegia and then bladder and bowel disturbance. On magnetic resonance imaging, the cauda equina was diffusely enlarged and enhanced with gadolinium. The brainstem and cerebellum were also enhanced with gadolinium along their surface. The differential diagnosis of the patient included meningeal tumors (other than lymphomas), lymphomas, or sarcoidosis. The biopsy of the cauda equina was planned for a definite diagnosis, but because the patient deteriorated so rapidly, it was not performed. Eventually, she was affected by cranial nerve palsies. With the definite diagnosis being undetermined, the patient died approximately 1.5 years after the onset of disesase. At autopsy, the cauda equina was replaced by a bulky mass composed of atypical B-lymphoid cells, consistent with diffuse large B-cell lymphoma (DLBCL). The spinal cord was heavily infiltrated, as were the spinal/cranial nerves and subarachnoid space. There was metastasis in the left adrenal. The patient was finally diagnosed postmortem as PCEL with a DLBCL phenotype. To date, there have been a limited number of autopsied cases of PCEL and non-PCEL primary neurolymphomatosis (nine cases in all, including ours). The diagnosis is, without exception, B-cell lymphoma including DLBCL, and the histology features central nervous system parenchymal infiltration, nerve root involvement, and subarachnoid dissemination (lymphomatous meningitis). Metastases are not uncommon. All clinicians and pathologists should be aware of lymphomas primarily involving the peripheral nervous system.

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.

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.

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.

Neurolymphomatosis in the Cauda Equina Diagnosed by an Open Biopsy

Neurolymphomatosis is a rare form of extranodal malignant lymphoma defined as the infiltration of malignant lymphocytes into the central or peripheral nerve. We herein report a case of neurolymphomatosis in the cauda equina diagnosed by an open surgical biopsy. He presented with muscle weakness, atrophy, numbness and hypoesthesia in the bilateral lower extremities with the accumulation of ¹⁸fluoro-2-deoxyglucose (FDG) in the bilateral cauda equina. Cerebrospinal fluid cytology (three times) and flow cytometry (two times) and biopsies of the left sural nerve, bone marrow, paranasal sinus and left testis were all negative for malignancy, so finally we performed a surgical open biopsy of the cauda equina by laminectomy and diagnosed him with diffuse large B-cell lymphoma in the cauda equina. He was successfully treated with the disappearance of the FDG accumulation for a long time. The present case suggested that an early open biopsy of the cauda equina may be considered for cases of suspected neurolymphomatosis in the cauda equina for a good outcome.