A man in his early 50s with focal segmental glomerulosclerosis and kidney transplantation 10 years earlier presented with progressive numbness and weakness of the right arm. Neurological examination showed decreased pinprick sensation in C6–C8 dermatomes and mild weakness in corresponding myotomes. Cervical spine MRI revealed a 1.1 × 0.5 × 0.7 cm rim-enhancing intramedullary lesion at C1 with restricted diffusion and surrounding edema extending to C3. The leading provisional diagnosis was CNS-PTLD, although pyogenic abscess, metastasis, and glioblastoma were also considered.
Because of the lesion’s high-risk intramedullary location, biopsy was initially deferred after multidisciplinary discussion. The patient received intravenous dexamethasone 4 mg every 6 hours, ceftriaxone, and ampicillin, with reduced immunosuppression. MRI initially showed partial improvement, but symptoms and lesion size worsened after steroid taper. A subsequent C1–C2 biopsy confirmed CD20-positive, EBER-negative lymphoid cells consistent with PTLD. The patient commenced R-CHOP chemotherapy but developed Chryseobacterium indologenes septic shock and multiorgan failure, leading to death two weeks later.