Thymus hyperplasia after lymphoma drug therapy: the role of PET/CT


I.V. Poddubnaya, N.A. Ognerubov, T.S. Antipova

1) Russian Medical Academy of Continuous Professional Education, Moscow, Russia; 2) G.R. Derzhavin Tambov State University, Tambov, Russia; 3) Center for Nuclear Medicine “Center for PET Technology”, Tambov, Russia
Background. The thymus is a lymphoid organ where mature and naive T-lymphocytes are synthesized. A number of factors (age, stress, toxic effects, including chemotherapy, radiation therapy, surgery, hormone therapy, etc.) can lead to a violation of its structure and functional activity in cancer patients. This manifests itself in the form of hyperplasia, which can be interpreted as a residual tumor, or a recurrence of the disease. Due to the plasticity of the thymus, this process is reversible.
Objective. Evaluation of the role of PET/CT in the diagnosis of thymic hyperplasia after drug therapy for lymphomas.
Methods. We performed a retrospective analysis of the results of PET/CT with 18F-fluorodeoxyglucose in 103 patients with stage II–III Hodgkin’s lymphoma and non-Hodgkin’s lymphoma after drug treatment for 2018–2020. PET/CT scanning was performed on an Optima PET/CT 560 (GE) tomograph at various stages of treatment and follow-up.
Results. Thymus hyperplasia was detected in 10 patients (9.7%) in the age group from 26 to 56 years, the median was 35.7 years. The vast majority of patients were under the age of 40 years – 8/80%, among them 9 women and 1 man. Hodgkin’s lymphoma was observed in 7 patients, non-Hodgkin’s lymphoma – in 3 cases. Patients underwent polychemotherapy according to BEACOPP schemes for Hodgkin’s lymphoma or R-CHOP immunochemotherapy for non-Hodgkin’s lymphomas. Thymus hyperplasia was detected, according to PET/CT data, 5–12 months (on average 8.4 months) after complete clinical and metabolic remission. The maximum standardized uptake value SUVmax ranged from 1.98 to 3.28; median – 2.52. Patients were followed-up for an average of 26 months, with no signs of recurrence of the disease.
Conclusion. Thymus hyperplasia after effective drug therapy in patients with lymphomas was observed in 9.7% of cases. It was characterized by the appearance of a volumetric formation in the anterior superior mediastinum, which had a triangular shape, the apex facing the sternum, a heterogeneous or soft tissue structure with fixation of 18F-fluorodeoxyglucose. The median SUVmax was 2.52. Hyperplasia developed after an average of 8.4 months after completion of therapy. PET/CT is considered the method of choice for the differential diagnosis of thymus hyperplasia and the exclusion of the progression of the tumor process.

About the Autors

Corresponding author: Nikolay A. Ognerubov, Dr. Sci. (Med.), Cand. Sci (Law), Professor, Honored Worker of the Higher School of the Russian Federation, Honored Doctor of the Russian Federation, Head of the Department of Oncology, G.R. Derzhavin Tambov State University, Tambov, Russia;

Similar Articles

Бионика Медиа