Disseminated Lymphoma Evolving into Neurolymphomatosis during Mid-cycle of Chemotherapy Detected by (18)F-FDG PET/CT.

Dear Editor, Neurolymphomatosis is a rare clinical entity and has mainly been described as primary lymphomatous infi ltration of the nerves and as a relapse or progression of disease after previous treatments. In this case report, we describe an unusual occurrence of neurolymphomatosis evolving in mid-cycle chemotherapy. Case Report An 80-year-old Chinese lady was diagnosed with diffuse large B-cell lymphoma (DLBCL) involving cardiac, nodal and bony disease. She was fi rst investigated for chest pain with breathlessness and a 2D echocardiogram showed a large circumferential pericardial effusion with evidence of cardiac tamponade as well as an echodense mass seen adherent and anterior to the right ventricle and right ventricle outfl ow tract (RVOT) region with RVOT compression. She underwent a left anterior thoracotomy, pericardial window, mediastinoscopy and biopsy; histology of her mediastinal lymph node was consistent with DLBCL. 18 F-fl uorodeoxyglucose positron emission tomography/ computed tomography (FDG-PET/CT) was performed using a GE Healthcare Discovery PET/CT machine with 10.0 millicurie of FDG injected. The scan was performed 75 minutes after the radiotracer administration. Hypocount measurement was 6.0 mmol/L prior to the scan. Findings showed a hypermetabolic nodular soft tissue thickening along the pericardium as well as pericardial effusion. Multiple foci of FDG uptake were also seen in the bones and in lymph nodes above and below the diaphragm. Bone marrow aspirate had no morphological evidence of lymphomatous infi ltration but trephine showed mildly hypocellular trilineage haematopoiesis with minimal, concordant B-Lymphomatous infi ltration. Flow cytometry noted approximately 3% atypical B lymphocytes which express CD19+, CD20+, SMIG+, predominantly CD5-, CD23-, FMC7-with lambda light chain restriction compatible with clonal B cells. The International Prognostic Index was 4. She was treated with her fi rst cycle of R-CHOP chemotherapy regimen consisting of rituximab, cyclophosphamide, hydroxydaunorubicin (doxorubicin), Oncovin (vincristine) and prednisolone displaying good clinical improvement. A repeat 2D echocardiogram done 16 days later showed resolution of the cardiac mass and pericardial effusion. The patient presented after her third cycle of R-CHOP with complaints of new onset glove and stocking numbness. Physical examination revealed hand numbness up to wrist and lower limb numbness up to mid-calf on both sides. A magnetic resonance imaging (MRI) study of the brain and spine was performed (Siemens MAGNETOM Avanto, 1.5 Tesla). Apart from degenerative changes such as disc bulges and lumbar spondylosis, the MRI study showed no overt leptomeningeal enhancement, or any intracranial abnormality detected and no MR features to suggest …