Primary Non-Germinal Center-Type Large B-Cell Lymphoma Involving the Thoracic Epidural Space, Cauda Equina, and Filum Terminal: Diagnosis and Treatment using Biportal Endoscopic Spine Surgery – A Case Report and Literature Review

Background and Clinical Significance: We report a rare case of a 66-year-old male with malignant non-germinal center-type large B-cell lymphoma involving the thoracic epidural, cauda equina, and filum terminale simultaneously. Case Presentation: The patient complained of back pain, rapid progressive numbness, and motor palsy in both legs in one month. Neurological examination revealed grade 2 muscle power in both lower limbs, hypesthesia below the T8 dermatome, and bladder and bowel dysfunctions. Magnetic resonance imaging (MRI) with contrast showed a well-defined extradural lesion extending from the T7 to T9 level, with severe spinal cord compression. Additionally, it revealed enlargement of the cauda equina occupy-ing the extradural space from the L1‑S1 level. The lesion appeared isointense on T1, mildly hyperintense on T2-weighted images, and exhibited homogeneous enhance-ment on post-contrast images. To relieve the patient’s spinal cord compression as soon as possible and allow the patient to recover quickly after surgery, we performed uni-lateral biportal endoscopy (UBE) to completely remove the T7-9 epidural lesion. The immunohistochemical assessment confirmed a histological diagnosis of diffuse large B-cell lymphoma, a non-germinal center type. The patient received radiotherapy to the thoracic and lumbosacral areas (50 Gy) and chemotherapy with six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) after sur-gery. Follow-up positron emission tomography (PET) scan and MRI performed 4 months after surgery revealed complete remission of the lesion. The patient was able to walk using a walker after therapy. Conclusions: UBE is a favorable option for selected patients requiring immediate chemotherapy or radiotherapy owing to its reduced tissue trauma compared to traditional open surgery.