FDG Pet/Ct Detection of Neurolymphomatosis in Relapsed Burkitt Lymphoma With Excellent Early Response to Intrathecal and Systemic Therapy

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma with frequent extranodal spread and risk of central nervous system (CNS) involvement. FDG PET/CT is central for staging and response assessment using the Deauville 5-point scale (D5PS). Neurolymphomatosis (NL) infiltration of peripheral nerves/roots by lymphoma ‒ is uncommon and may be occult on MRI; FDG PET/CT can reveal FDG-avid nerve roots and plexuses. To report FDG PET/CT identification of FDG-avid cervical (C8) and lumbar (L4) nerve roots in relapsed BL with leptomeningeal disease, and to correlate imaging with CSF flow cytometry and early therapeutic response. Male, 48 years, BL (stage IV at baseline), previously treated, achieved interim D5PS 3. In Feb/2021, presented with headache; CSF flow cytometry confirmed leptomeningeal relapse. Brain MRI was normal. Whole-body FDG PET/CT (60 min post-injection; hybrid scanner, BLINDING) showed two focal FDG-avid nerve roots (C8 right, SUVmax 15.7; L4 right, SUVmax 10.9) with mediastinal/liver SUVs 3.0/4.6. Findings were consistent with NL and CNS relapse (D5PS 5). Patient received intensified intrathecal chemotherapy (multiple administrations) plus ICE systemic salvage. Serial CSF analyses converted to negative on two consecutive assessments, with symptom resolution and hematologic recovery, indicating excellent early response. No other new FDG-avid lesions were detected outside the nerve roots at that time. This case underscores three practice points: (i) FDG PET/CT can detect NL in BL even when MRI is non-diagnostic, highlighting FDG-avid nerve roots/plexuses (3,4); (ii) Deauville-based interpretation remains standard in FDG-avid lymphomas, supporting imaging-guided therapeutic decisions (1,2); (iii) In BL, where CNS relapse is a known adverse prognostic factor, recent data show that achieving early complete response (CR) translates into markedly better event-free and overall survival (EFS/OS) (5). Thus, in cases of radiculopathy or new neurologic symptoms in aggressive B-cell lymphoma, especially BL, prompt PET/CT evaluation followed by rapid intrathecal/systemic therapy may alter the historically poor prognosis of neurolymphomatosis and leptomeningeal involvement (6). Early achievement of metabolic remission in PET strongly correlates with favorable outcome and should be integrated into multidisciplinary management.