TY - JOUR T1 - A case of comparison of PET/MR before and after treatment of Castleman disease in children JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1115 LP - 1115 VL - 62 IS - supplement 1 AU - YUE LIU Y1 - 2021/05/01 UR - http://jnm.snmjournals.org/content/62/supplement_1/1115.abstract N2 - 1115Introduction: Male, 13 years old. Suffered from right iliac waist pain for more than one month, accompanied by difficulty in walking. Tumor markers such as ferritin and squamous cell carcinoma antigen are increased. CT report from other hospital considers malignant tumors with lymph node metastasis. The biopsy showed that the lesion tissue was lymphoid tissue hyperplasia, mainly T lymphocyte hyperplasia, with less lymph node follicles, small blood vessels proliferated and expanded, and more plasma cells infiltrated. Pathology cannot determine the pathological type of the disease, and further PET/MR examinations are recommended. PET/MR showed that the right psoas major and iliopsoas muscles were swollen and blurred. There were multiple irregular soft tissue masses in the right psoas major, iliopsoas muscle, and right iliac fossa. The right ureter and iliac vessels were compressed. The signal of the mass is not uniform, FDG metabolism is increased, SUVmax=25.17. There are multiple enlarged lymph nodes in retroperitoneum, mesenteric, right iliac fossa, bilateral iliac vessels, right groin, and right thigh root. FDG metabolism is increased, SUVmax=11.09. We considered a possibility of Catleman's disease, and suggested to perfom a second biopsy,the pathology of the second biopsy showed lymphoid follicular atrophy, hyaline degeneration of blood vessels in some follicles, proliferation of lymphoid tissue between follicles, abundant small blood vessels, proliferation of spindle fibroblasts and histocytes, and hemosiderin deposition. Immunohistochemistry: S-100, CD1a scattered +, CD68+, CD3+, CD20 follicular area+, CD79a follicular area+, CD45+, CD56+, CD10 germinal center+, CD21 germinal center+, the pathological diagnosis is Castleman disease. The lesions basically disappeared after chemotherapy with a good prognosis. ER -