Primary Extraskeletal Osteosarcoma Of The Ureter: Report Of A Case

Extraskeletal osteosarcoma (EOO) is a rare malignant mesenchymal tumor that grows in soft tissue without attaching to skeleton. Extraskeletal osteosarcoma arising in the ureter is extremely rare and only 3 cases have been reported in detail to date. In our study, an 81-year-old man presented with a 1-month history of painless naked hematuria. Computed tomography (CT) scan revealed that there was a solid tumor in the left distal ureter. Subsequently, radical resection was performed. Immunohistochemical staining of specimens showed that the tumor cells were positive for vimentin and Ki-67, but negative for other specific markers. The findings favored the primary ureteral osteosarcoma. Adjuvant radiotherapy was recommended but was refused. Four months later, regular clinical follow-up revealed no evidence of recurrence. The aim of present study is to report an additional case of ureteral osteosarcoma, focusing on the characteristics, including pathogenesis, diagnosis, treatment and outcomes.