Thymic hyperplasia following chemotherapy in adults with lymphoma: ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography findings and correlation with T cell repopulation

Abstract

Thymic hyperplasia (TH) after chemotherapy is an infrequent phenomenon in adults. This study analyzed the incidence and metabolic activity of TH on ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in this population. By reviewing 471 PET/CT recordings of 211 adults with lymphoma, increased FDG uptake within an enlarged thymus regarded as TH was observed in 27 patients aged 18–53 years. FDG uptake in hyperplastic thymus was mild and diffuse, with a maximum standard uptake value (SUV_max) of 2.6 ± 0.9. Its intensity varied with different occurrence times following chemotherapy. In addition, by comparing the recovery of T cell subsets in patients with TH (n = 20) and without TH (n = 28), no impact of the presence of TH was found on the repopulation of total CD4 + and CD8 + T cells within the first year after treatment. These data may be helpful to avoid misinterpretation of increased thymic uptake in adults.

Keywords::

• Thymus
• hyperplasia
• adult
• lymphoma
• chemotherapy
• PET/CT

Acknowledgements

This study was supported by the National Natural Science Foundation of China (Grant Nos. 30871104, 30971296, 81170488, 81370657), the Natural Science Foundation of Jiangsu Province (Grant No. BK2010584), Key Projects of Health Department of Jiangsu Province (Grant No. K201108), Jiangsu Province's Medical Elite Program (Grant No. RC2011169), a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institute (No. JX10231801), National Public Health Grand Research Foundation (No. 201202017), the Program for Development of Innovative Research Teams in the First Affiliated Hospital of Nanjing Medical University and a Project of National Key Clinical Specialty.

Potential conflict of interest

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