Inflammatory Demyelinating Lesions: True Sentinel Lesion or Immune-Mediated Response to Lymphoma?

Myelin oligodendrocyte glycoprotein antibody-associated disease preceding primary central nervous system lymphoma: causality or coincidence?

INTRODUCTION

Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphomatous malignancy that affects the brain, spinal cord, leptomeninges, or eyes, in the absence of systemic diffusion. Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a newly identified benign immune-mediated CNS inflammatory disorder with specific anti-MOG antibody seropositivity. These two seemingly unrelated nosological entities both have abundant clinical and radiological manifestations, and whether there is a potential link between them is unclear.

CASE REPORT

We describe a 49-year-old man who presented progressive headache, dizziness, and unsteady gait with multifocal scattered T2 hyperintensities with contrast enhancement. The serum anti-MOG antibody test was positive, and a brain biopsy showed inflammatory infiltration. Initially, he was diagnosed with MOGAD and his condition improved after corticosteroid therapy. The patient relapsed with exacerbation of symptoms and neuroimaging showed new mass-forming lesions four months later. A second brain biopsy confirmed PCNSL.

DISCUSSION

This is the first report of histologically confirmed successive MOGAD and PCNSL. Our case broadens the phenotypic spectrum of sentinel lesions in PCNSL. Though rare, PCNSL should be considered in patients diagnosed with benign CNS inflammatory disorder and responding well to steroid treatment when their clinical symptoms worsen and the imaging deteriorates. A timely biopsy is critical for accurate diagnosis and appropriate therapy.

Longitudinally extensive transverse myelitis preceding primary central nervous system lymphoma: Spinal sentinel neuroinflammation

65-year-old female diagnosed with longitudinally extensive transverse myelitis. She had excellent response to immunotherapy despite her atypical features, and her spinal lesion was fully recovered in the second month of the treatment. Nine months after, she was diagnosed with primary cerebral central nervous system lymphoma while there was no recurrence of the spinal cord lesion as her most recent follow-up visit being 2 years after the LETM. Spinal sentinel neuroinflammation preceding primary central nervous system lymphoma might represent a valuable etiology in the differentials of LETM, as illustrated here.

Enhancement pattern of demyelination-mimicking cerebral B-cell lymphoma

BACKGROUND

CNS B-cell lymphoma mimicking demyelinating diseases creates a diagnostic dilemma. This study aimed to determine the specific MR features of CNS B-cell lymphoma to facilitate the early identification of the disease.

METHODS

We retrospectively reviewed the brain MRI of biopsy-confirmed CNS B-cell lymphoma patients. They were initially diagnosed with CNS demyelination, and these images were compared with those of actual patients with demyelinating diseases.

RESULTS

A total of 20 patients with CNS B-cell lymphoma and 12 patients with demyelination were included in this study. Cohesive enhancement with satellite enhancing foci surrounded by prominent non-enhancing areas of oedema is the major contrast-enhancing pattern of lymphoma patients, accounting for 81% (13) of patients with primary diffuse large B-cell lymphoma (DLBCL). This imaging pattern revealed a sensitivity of 81% and a specificity of 75% for lymphoma in the differential diagnosis between primary DLBCL and demyelinating disease in our cohort. Among these lesions, most of the nodules were located deeply, which yielded a specificity of 100% and a sensitivity of 69% for primary DLBCL. Enhancement in a single pattern (mainly ring-like, patchy or punctate) (57%) and no enhancement (30%) were commonly observed in demyelinating lesions, distinct from primary DLBCL (p<0.05).

CONCLUSIONS

Lesions with cohesive enhancement and satellite foci on T1 contrast-enhanced imaging could be a specific hallmark of CNS B-cell lymphoma, suggesting the need to withdraw steroidal therapy withdrawal and biopsy confirmation.