Papandreou et al. Journal of Medical Case Reports 2010, 4:70 http://www.jmedicalcasereports.com/content/4/1/70 Page 2 of 3 Figure 1 Computed tomography scan shows a large solitary polypoid tumour arising from the bladder dome. Also notice left hip arthroplasty. Figure 3 Malignant, lace-like osteoid formation. Notice the nuclear polymorphism of the malignant cells producing malignant woven bone. (HE, × 200) Figure 2 Cancellous bone and malignant, lace-like osteoid formation by the spindled sarcomatous cells and in between these cells chondroid matrix (HE, × 100). of primary osteogenic sarcoma of the urinary bladder. Other localization studies including a chest X-ray and a bone scan were unremarkable. Due to the significant comorbidity of our patient, who had a coronary artery disease and restrictive respiratory disease, he was offered partial cystectomy. However, he refused this option and underwent external beam radia- tion therapy (EBRT) instead. Our patient declined to receive adjunctive chemotherapy. In the following Figure 4 Computed tomography scan seven months afterdiagnosis shows extravesical tumour extension and bowel invasion. months, he had two episodes of proven urinary tract infection. Seven months after diagnosis, he developed ascites. A CT scan at that point showed extravesical tumor extension and bowel infiltration (figure 4). Our patient died eight months after diagnosis, experiencing severe lower urinary tract symptoms (LUTS) and abdominal pain the last months of his life. Discussion Only 32 cases of primary osteosarcoma of the bladder have been so far reported in the English literature [1-3]. To the best of our knowledge, this is the fourth reported case where this type of tumor occurs in a patient with a history of TCC or simultaneously with TCC [4-6].