¹⁸F-FDG PET/CT and contrast-enhanced CT in the diagnosis of Castleman disease

Castleman disease (CD) is a rare group of lymphoproliferative disorders, which is easily confused with lymphoma or other solid tumors. Hence, this study aimed to investigate the diagnostic role of ¹⁸F-FDG PET/CT and contrast-enhanced CT (CECT) in patients with CD. Clinicopathological characteristics, and ¹⁸F-FDG PET/CT and CECT findings and parameters were retrospectively reviewed in 32 patients with CD. These 32 patients (12 males, 20 females; median age, 41 years) consisted of 17 unicentric CD (UCD) patients and 15 multicentric CD (MCD) patients. Compared with MCD, UCD had a higher prevalence in female (82.4% vs. 40.0%) and hyaline vascular subtype (94.1% vs. 40.0%) (P<0.05). FDG uptake was avid in all cases, including moderate uptake in 7 cases and intense uptake in 25 cases. The median SUVmax, SUVmean, MLV, and TLG of all cases were 4.4 (range, 1.4-23.6), 2.7 (range, 1.1-15.2), 26.6 (range, 4.8-393.0), and 78.8 (range, 9.4-1545.6), respectively. The lesions of 29 cases showed homogeneous enhancement, and marked enhancement was observed in 27 cases. ¹⁸F-FDG PET/CT corrected 6.3% CECT diagnoses, while CECT corrected 37.5% PET/CT diagnosis. The accuracy of combined PET/CT and CECT was superior to PET/CT or CECT alone (78.1%, 31.3%, and 62.5%). Besides, higher SUVmax and SUVmean were found in male subjects, MCD, and plasma cell subtype (P<0.05), while higher MLV and TLG were observed in larger lesion size and volume (P<0.05). Castleman disease most commonly appears as marked and homogeneous enhancement meanwhile with moderate or intense FDG uptake. ¹⁸F-FDG PET/CT combined with CECT was the effectively diagnostic modality for CD. The glucose metabolism of CD was associated with gender, clinical classification, histopathological classification, and lesion size and volume. (author)