Interdigitating dendritic cell sarcoma presenting in the kidney combined with retroperitoneal leiomyosarcoma: A case report and literature review

Interdigitating dendritic cell sarcoma (IDCS) and retroperitoneal leiomyosarcoma are rare tumors. The optimal diagnosis, treatment and prognosis remain unknown. The current case report presents a 46-year-old male who exhibited with a left renal mass combined with a periprostatic mass. The patient underwent surgery twice, respectively for the resection of the two masses. The postoperative pathological examination confirmed the diagnosis of IDCS presenting in the kidney and retroperitoneal leiomyosarcoma in the pelvis. To the best of our knowledge, it is the first report of IDCS in the kidney and of the combined appearance of IDCS and retroperitoneal leiomyosarcoma in the same patient.