A case report of abdominal metastatic dermatofibrosarcoma protuberans misdiagnosed as gastrointestinal stromal tumor.

"Declarations Ethics approval and consent to participateThe participant in our study provided signed informed consent. This study was approved by the ethics committee of the Zhongshan Hospital, Fudan University, and the IRB is B2021-842R. Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding The study was supported by the National Clinical Key Specialty Project - Next-generation Integrated Pathological Diagnosis of Oncologic Diseases under the Department of Pathology (YWP2023-001); Shanghai Clinical Specialty Construction Project (shslczdzk01302); Shanghai Science and Technology Innovation Action Plan - Natural Science Foundation Project (23ZR1410000); Shanghai Science and Technology Innovation Action Plan - Natural Science Foundation Project (23ZR1410200)."