Author(s)

Atsushi K. Kono¹, Kazuhiro Kitajima², Hiroshi Mmatsuoka³, Kyoko Otani⁴, Tomoo Itoh⁴, Kazuro Sugimura²

¹Department of Radiology, Kobe University Hospital, Kobe, Japan.
²Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
³Division of Medical Oncology/Hematology, Department of Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
⁴Department of Diagnostic Pathology, Kobe University Hospital, Kobe, Japan.

Introduction: The use of methotrexate (MTX) for rheumatoid arthritis (RA) is increasing. However, the immune suppression state leads to the occurrence of lymphoproliferative disorder (MTX-LPD). The purpose of this study was to describe the findings of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in MTX-LPD patients, and compare it with non-MTX-related malignant lymphoma (ML). Materials and Methods: We retrospectively reviewed 11 MTX-LPD patients (9 female, mean age 68.3 years) and 21 ML patients (7 female, mean age 60.6 years) with a histopathological diagnosis. FDG-PET imaging was performed using a standard oncology procedure. We assessed the disease distribution based on FDG-PET images and measured the maximum standardized up take values (SUVmax) for each region. Results: Mean values of SUVmax in MTX-LPD and ML were 14.6 and 17.2, respectively (p = 0.49). In MTX-LPD, 55 lesions met the Cotswold classification, consisting of 37 nodal and 18 extranodal lesions. In ML, 82 lesions were found, consisting of 68 nodal and 14 extranodal lesions. MTX-LPD showed a higher incident of the involvement in extranodal lesions throughout the whole body (p < 0.001). Conclusion: Because this disease occurs widely throughout the whole body, we need to pay attention to the less frequent sites as well when performing PET imaging in patients with MTX-LPD.

Fluorodeoxyglucose (FDG) F 18, Lymphoma, Methotrexate, Positron-Emission Tomography (PET), Rheumatoid Arthritis

Kono, A. , Kitajima, K. , Mmatsuoka, H. , Otani, K. , Itoh, T. and Sugimura, K. (2014) Findings of ¹⁸F-Fluorodeoxyglucose Positron-Emission Tomography in Methotrexate-Related Lymphoproliferative Disorder. Open Journal of Radiology, 4, 293-300. doi: 10.4236/ojrad.2014.44038.