Bilateral trigeminal nerve recurrence of non-hodgkin lymphoma revealed with FDG PET/CT
A 63-year-old male patient treated for diffuse large B cell type NHL of left testis was in complete remission for 5 years. He presented with weakness, headache and trigeminal neuralgia to internal medicine. He was referred to Nuclear Medicine department for FDG PET/CT imaging to search for possible recurrence. For PET/CT examination, patient was intravenously injected 550 MBq of F18-FDG after 8 h of fasting period. After one hour of waiting period in a silent room, patient was imaged using an integrated PET/CT camera, which consisted of a 6-slices CT gantry integrated on a LSO based full ring PET scanner (Siemens Biograph 6). The injected dose, injection time and body weight were used to calculate the maximum standardized uptake values (SUVmax). PET and fusion images showed bilateral pathological intense FDG uptake in trigeminal nerves with a SUVmax of 16,6 [, arrows]. There were also increased FDG accumulation (SUVmax = 6,4) at the D1 spinal nerve root and slightly increased tracer uptake located at spinal cord between the level of D12 and cauda equina. Cranial MRI revealed thickening of bilateral 5th cranial nerve [Figure and ]. Spinal MRI demonstrated pathologic signal changes at the spinal cord between D12 level and cauda equina suspicious for lymphomatous involvement. Lumbar puncture was performed and cytopathology revealed lymphoma involvement. After administration of 6-cycles of intrathecal methotrexate, repeated CSF analysis was negative.