A 56-year-old man with hypertension, hyperlipidemia, and diabetes presented with acute onset L sided weakness with right midbrain, cerebral peduncle and thalamic increase DWI signal and antiphospholipid antibodies, initially suspected for possible stroke. Close follow up imaging with contrast study was planned due to atypical imaging findings. Patient was discharged to acute rehab on therapeutic Warfarin. Two weeks later, he returned with poor mental status, worsening left sided weakness, numbness, dysarthria and apathy. Repeat MRI brain showed increased DWI signal with increased mass effect.
Post contrast MRI brain revealed expansile infiltrative FLAIR and DWI hyperintensity in the right thalamocapsular region extending into the midbrain and anterior cerebellum with superimposed patchy enhancement in the right thalamocapsular area. Findings are suspicious of CNS lymphoma vs high-grade glioma vs inflammatory and infectious processes .Lumbar puncture was non-revealing.
A right thalamic biopsy confirmed neoplastic B-cells, positive for Bcl-2, subset Bcl-6 (50%) and MUM-1 (50%), negative for CD10, CD30, and Bcl-, compatible with primary diffuse large B-cell lymphoma of CNS.
Immediate treatment with R-MPV regimen (rituximab, methotrexate, procarbazine, vincristine) was started, in addition to solumedrol and whole brain radiation therapy with rapid clinical improvements after steroids treatment before combination chemotherapy.