Case Report: Probable CLIPPERS in a patient with cutaneous T-cell lymphoma in remission: 5-year follow-up.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) may be associated with lymphoma, although the underlying relationship between these entities remains unclear. While the diagnosis is centered on specific imaging characteristics and can be difficult to establish, CLIPPERS typically responds robustly to corticosteroid therapy. We report a 60-year-old woman who presented with memory and cognitive impairment 4 years after achieving complete remission from cutaneous T-cell lymphoma. Brain MRI revealed atypical CLIPPERS features, including scattered enhancing lesions in both supratentorial and infratentorial regions. During a subsequent relapse, transient low-titer serum anti-myelin oligodendrocyte glycoprotein antibodies (titer 1:32) were detected, which later reverted to negative. Initial PET/CT demonstrated transient hypermetabolic splenic lesions suspicious for lymphoma involvement, which resolved on follow-up imaging. Subsequently, new skin lesions with T-cell atypia developed; however, skin biopsy findings, CSF T-cell receptor gene rearrangement studies, and clinical evaluations did not provide evidence supporting lymphoma recurrence or CNS involvement. After comprehensive evaluation and exclusion of alternative diagnoses, follow-up brain MRI revealed characteristic "pepper-like" pontocerebellar enhancing lesions. In combination with a favorable response to high-dose corticosteroids, these findings supported a diagnosis of probable CLIPPERS. This case highlights the complex interplay among CLIPPERS, potential neoplastic states, and transient autoantibodies during long-term follow-up, underscoring the need for prolonged clinical surveillance for possible lymphoma recurrence. It also underscores the diagnostic complexity of CLIPPERS in patients with prior lymphoma and suggests that transient low-titer MOG-IgG seropositivity should be interpreted cautiously in the absence of CSF positivity or a typical MOGAD phenotype.