The clinical diagnosis and treatment processes of four children with Castleman disease admitted to Guangzhou Women and Children's Medical Center, Guangzhou Medical University, from March 2021 to December 2024 were retrospectively analyzed. Among them, three cases were unicentric Castleman disease, presenting as abdominal pain with ileocecal ulceration, concomitant classical Hodgkin lymphoma, and choledochal cyst, respectively. One case was severe idiopathic multicentric Castleman disease involving lymph nodes in the neck and axillary regions, presenting with fever, abdominal distension, generalized edema, fatigue, anemia, hepatic dysfunction, polyserous effusion, and other systemic manifestations. The three unicentric cases underwent complete surgical resection of enlarged lymph nodes. The case with abdominal pain received subsequent enteral nutrition and oral thalidomide therapy. The case complicated with Hodgkin lymphoma received chemotherapy according to the Hodgkin lymphoma protocol. The severe multicentric case was treated with rituximab combined with vincristine, pirarubicin, cyclophosphamide, and prednisone. All four cases achieved complete remission during 6 to 30 months of follow-up. Clinical manifestations of Castleman disease in children lack specificity. Surgical resection remains the main treatment for unicentric cases, while treatment regimens for multicentric cases are more varied. The overall prognosis is favorable. Further studies are needed to determine the optimal treatment for Castleman disease complicated by gastrointestinal ulcers and severe idiopathic multicentric Castleman disease.