Metabolic characteristics of Castleman disease on 18F-FDG PET in relation to clinical implication

Castleman disease (CD) is a benign lymphoproliferative disease, which usually shows hypermetabolism on 18F-FDG PET/CT. In this study, we investigated metabolic characteristics of CD in consecutive series of patients and analyzed 18F-FDG uptake with regard to major clinicopathologic factors, to investigate clinical implication of 18F-FDG uptake in CD.

Twelve patients (5 men and 7 women; mean age, 52 ± 14 years) with pathologically confirmed CD, who underwent 18F-FDG PET/CT, were retrospectively enrolled, and their images were analyzed. The cases were composed of 10 first diagnosed and 2 relapsed cases. SUV(max) was measured for each lesion. Metabolic characteristics were compared according to clinical and pathologic characteristics.

All the 18F-FDG PET/CT images showed hypermetabolic lesions including small lymph nodes of less than 1 cm. The average SUV(max) was 5.8 ± 4.1 with a varying range of 2.4 to 17.1. SUVmax was significantly higher in multicentric than in unicentric disease cases (7.0 ± 4.6 vs 3.3 ± 1.1; P = 0.048) and in the patients with clinical manifestation than the other group (7.1 ± 4.5 and 3.1 ± 0.8, respectively; P = 0.028).

18F-FDG PET/CT is an effective diagnostic imaging for diagnosis of CD. Castleman disease shows moderately increased 18F-FDG uptake. In addition, the uptake is well correlated with disease multicentricity and clinical manifestation, suggesting that it would be a significant imaging marker for severity or prognosis of CD.