Abstract: Background and purpose: Positron emission tomography-computed tomography (PET/CT) is playing an increasingly important role in the diagnosis, therapy and follow-up of lymphoma patients. This study aimed to explore clinical and pathological features and bone marrow infiltration status in lymphoma patients with diffused high bone marrow glucose uptake on ¹⁸F-FDG PET/CT. Methods: It was a retrospective study. Bone marrow infiltration status, pathological and clinical data from 62 cases of pathologically diagnosed lymphoma and diffused high bone marrow glucose uptake were analyzed. Results: Distribution of histopathological subtype in those cases was in accordance with that in previously reported Chinese lymphoma patients. Significant difference was demonstrated in standard uptake value (SUV) between patients with aggressive and indolent histopathological subtypes (8.43 vs 5.38, P=0.048), patients with and without B symptoms (8.30 vs 5.72, P=0.033), and patients with and without bone marrow infiltration (8.78 vs 6.96, P=0.020). 32 patients were diagnosed as “bone marrow infiltration” by bone marrow biopsy. There was significant difference in histopathological subtype distribution between patients with and without bone marrow infiltration (P=0.001). In patients with bone marrow infiltration, there were higher proportions of mantle cell lymphoma, nodal marginal zone B cell lymphoma, Burkitt’s lymphoma and anaplastic large cell lymphoma. In contrast, patients without bone marrow infiltration suffered more from diffuse large B-cell lymphoma, peripheral T cell lymphoma, enteropathic T cell lymphoma and extranodal NK/T-cell lymphoma (nasal type). False positive results in bone marrow glucose uptake may be caused by fever or anemia. Conclusion: Diffused high bone marrow glucose uptake on ¹⁸F-FDG PET/CT should be evaluated in combination with the uptake values, clinical features and histological subtypes, to minimize the misdiagnosis and to better guide staging and therapy of lymphoma.

Key words: Positron emission tomography-computed tomography, Diffused high bone marrow glucose uptake, Lymphoma, Bone marrow infiltration