Papandreou et al. Journal of Medical Case Reports 2010, 4:70 http://www.jmedicalcasereports.com/content/4/1/70 Osteosarcoma should be distinguished from other bone-forming tumors, such as carcinosarcoma and tran- sitional cell carcinoma with osseous metaplasia. It is not always easy to distinguish extraskeletal osteosarcoma from other sarcomas, which rarely produce metaplastic bone such as malignant fibrous histiocytoma, synovial sarcoma and epithelioid sarcoma. In most of these neo- plasms, osteoid or bone formation is confined in a small portion of the tumor and is relatively well differentiated, without the disorderly pattern and cellular/nuclear poly- morphism/pleomorphism of osteosarcoma. The charac- teristic microscopic pattern of our tumor, that is, the malignant, lace-like osteoid, produced in large amounts by the spindled sarcomatous cells, and the presence of chondroid matrix between these cells along with the above-mentioned immunoprofile and the absence of concurrent epithelial malignancy, supported the diagno- sis of primary osteosarcoma of urinary bladder [7-9]. The prognosis of bladder osteosarcoma is very poor, with most patients dying from the disease within six months. The tumor tends to be locally aggressive. Dis- tant metastases are uncommon and are usually confined to the lung. Recommendations to improve survival have included radical cystectomy with radiotherapy and/or chemotherapy, but most patients die of this disease regardless of the type of treatment [1,10]. However, there are publications that report success- ful treatment with a long follow- up. One patient was free of such disease 36 months after partial cystectomy [10] and another survived with no evidence of recur- rence after 51 months of combination treatment with radical cystectomy and chemotherapy [11]. A case of bladder osteosarcoma with markedly remission of pul- monary metastases after chemotherapy has also been reported [1]. In our case, our patient had a long history of TCC and also had significant comorbidity. He was thoroughly informed about the disease and finally decided to undergo EBRT. Although he lived few months more than usual, during the last four months, he suffered severe LUTS, abdominal pain and was heavily medicated with opioid analgesics. For the above-mentioned symp- toms, there was no obvious etiology other than radiotherapy. Conclusion Osteosarcoma of the bladder is a rare tumor with a dismal prognosis. External beam radiation therapy as adjunct to transurethral resection seems to provide no benefit for patients with primary osteosarcoma of urinary bladder. Moreover, it may be associated with poor quality of life and thus should be better to be avoided. Page 3 of 3 Consent Written informed consent was obtained from our patient for publication of this case report and accompa- nying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Abbreviations CT: Computed tomography; TCC: transitional cell carcinoma; EBRT: external beam radiation therapy; TURBT: transurethral resection of bladder tumor; LUTS: lower urinary tract symptoms. Author details 1Department of Urology, General Hospital of Arta, Greece. 2Department of Pathology, General Hospital of Arta, Greece. 3Department of Radiology, General Hospital of Arta, Greece. Authors’ contributions CP was involved in patient care, review of literature and writing of the manuscript. AS performed the histological examination and reviewed the literature. GK was involved in radiological evaluation of our patient. HD was involved in patient care and writing supervision. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Received: 18 September 2009 Accepted: 24 February 2010 Published: 24 February 2010 References 1. Berenson RJ, Steven F, Freiha FS, Kempson RL, Torti FM: Primary osteogenic sarcoma of the bladder. Cancer 1986, 57:350-355. 2. Rodríguez Alonso A, González Blanco A, Bonelli Martín C, Nogueira Carballedo C, García Rego JA, Cachay Ayala M, Lorenzo Franco J, Cuerpo Pérez MA, Nieto García J: Primary bladder osteosarcoma treated with hemicystectomy. Actas Urol Esp 2002, 26:226-230. 3. Baydar DE, Himmetoglu C, Yazici S, Kiziloz H, Ozen H: Primary osteosarcoma of the urinary bladder following cyclophosphamide therapy for systemic lupus erythematosus: a case report. 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Kato T, Kubota Y, Saitu M, Yaguchi H, Sasagawa I, Nakada T, Yuda F: Osteosarcoma of the bladder successfully treated with partial cystectomy. J Urol 2000, 163:548-549. 11. Phan CN, Wilkinson M, Cohen MB, Dunn S, Carroll P: Primary osteogenic sarcoma of the urinary bladder successfully treated with combination therapy. Urology 1994, 44:771-774. doi:10.1186/1752-1947-4-70 Cite this article as: Papandreou et al.: Primary osteosarcoma of the urinary bladder treated with external radiotherapy in a patient with a history of transitional cell carcinoma: a case report. Journal of Medical Case Reports 2010 4:70.