FDG-PET/CT imaging of elastofibroma dorsi

The purpose of this study was to assess retrospectively the characteristics of FDG uptake in elastofibroma dorsi using integrated PET/CT. From 10,261 oncology FDG-PET/CT scans performed over a 2-year period, findings suggestive of elastofiboma dorsi were observed in 46 FDG-PET/CT scans of 34 patients. As 20 patients had bilateral lesions and 14 had unilateral lesions, a total of 75 elastofibroma dorsi lesions on images were identified in this study. For visual analysis of intensity of FDG uptake , a four-point grading system was used: grade 0 for no uptake, grade 1 for less uptake than the liver, grade 2 for uptake comparable to the liver, and grade 3 for intense uptake greater than the liver. For quantitative analysis, the standardized uptake value (SUV) was calculated. The relationships between SUV and age, blood glucose level, lesion size, and related symptoms were also assessed. Among the 75 lesions, 4 had an uptake grade of 0, 41 had grade 1, 25 had grade 2, and 5 had grade 3. The mean SUV (+/- SD) of the 75 lesions was 2.0 +/- 0.63 (range 0-5.1). The Pearson correlation coefficient test indicated a weak positive correlation between SUV and lesion size and no correlation between SUV and either age or blood glucose level. The SUVs of patients with symptoms due to the disease and patients without symptoms were almost the same. Mild and moderate uptake of FDG is frequently observed in elastofibroma dorsi, which should not be misinterpreted as abnormal accumulation observed in malignant lesions.