The Role of 18F-FDG PET/CT in the Assessment of Patients with Intravascular Large B-Cell Lymphoma

Purpose: Intravascular large B-cell lymphoma (IVLBCL) is a rare neoplasm that could affect multiple organs and systems with no specific manifestations. The aim of this study was to investigate the diagnostic value of FDG PET/CT in IVLBCL. Methods: A retrospective study was conducted on 16 patients of IVLBCL, and their FDG-PET/CT results were reviewed. The maximum standardized uptake values (SUVmax) in examining organs were measured within the regions of interest (ROI). Images were considered abnormal when they revealed a clear focus with increased FDG uptake or showed non-specific signs, such as diffused FDG uptake in the spleen, bone marrow, or lungs. Results: Diffuse or local increased FDG uptake was observed in bone marrow in 13 (81.3%), in liver in 12 (75.0%), in spleen in 10 (62.5%), in lungs in 14 (87.5%), and in kidneys in 8 (50.0%) patients. Varying degrees of diffusely increased uptake in multiple organs was found to be the characteristics of 18F-FDG PET/CT images in IVLBCL patients. Conclusions: 18F-FDG PET/CT may contribute to the diagnosis in patients with suspected IVLBCL by providing precise biopsy sites when involvement of bone marrow, liver, spleen, and lungs occur. It also could provide valuable information as follow-up measurement for prognosis evaluation of IVLBCL. Fig. 1 Eight cases of FDG-PET/CT MIP images showed hepatosplenomegaly and hypermetabolic activity in the liver, spleen, and BM in varying degrees. (A) A 60-year-old woman was verified by BM biopsy. (B) A 58-year-old woman showed focal uptake in both caput humeri and underwent biopsy in the left one (black arrow) (C) A 47-year-old man showed diffuse skin FDG uptake and get a random biopsy. (D) A 33-year-old woman who showed diffuse lung FDG uptake and focal uptake in left lung nodules. Histopathology revealed by TBLB. (E) A 71-year-old man got liver biopsy in the focus of increased uptake in the right hepatic lobe (black arrow). (F) A 56-year-old woman showed the diffuse uptake in bilateral kidneys, which were significantly enlarged, and underwent renal biopsy. (G) A 61-year-old woman got adrenal biopsy on the right (black arrow), given bilateral adrenals hypertrophy with increased uptake. (H) A 45-year-old woman showed increased focal uptake in the left lobe of the thyroid (black arrow) and lymph nodes (black triangle). Histopathology by thyroidectomy indicated only nodal involvement, with the thyroid pathology attributed to nodular goiter. Focal uptake in the lymph node was r