A 35-year-old male with DiGeorge syndrome, chronic kidney disease and schizophrenia presented with subacute onset left-sided weakness. MRI revealed a T2-hyperintense spinal cord lesion extending from the caudal medulla to T2/T3 with enhancement at C3/C4. Other than mildly elevated protein, CSF studies were unremarkable including negative oligoclonal bands, cytology, and flow cytometry. Serum antibodies against aquaporin-4 and MOG were not detected, and infectious work up was negative. Although his baseline CD4 and CD8 T cell counts were normal, his class-switched CD27+IgD-IgM- B cells and IgM levels were low, and soluble IL-2 receptor was high. The patient had modest improvement following corticosteroids and plasmapheresis. However, he would relapse when steroids were tapered and subsequent MRIs showed disease progression with features consistent with the “trident sign.” Whole-body PET/CT demonstrated FDG uptake in the axillary lymph nodes, though a lymph node biopsy showed only reactive tissue. Given a clinical suspicion for granulomatous transverse myelitis, he was treated empirically with infliximab two years after presentation. Follow-up MRI eight weeks after treatment showed significantly decreased lesion size and enhancement.