[A case of sacral chordoma presenting as urinary retention].

A 71-year-old man was referred to our hospital complaining of urinary retention. He noticed a small mass on his buttocks about one year ago. Computed tomographic (CT) scan and magnetic resonance imaging (MRI) showed a large mass of 10 cm in diameter located in the retrovesical space. The mass extended to the surface of his buttocks and contained many calcified deposits, and was accompanied with a sacral bone fracture. Transdermic biopsy revealed the presence of sacral chordoma. Chordoma is a rare tumor, arising from remnants of the notochord and is locally progressive. Both tumor resection and diverting colostomy were performed at another hospital. In that operation his spinal cord was protected down to the second sacral level. Unfortunately after the operation, the patient suffered total urinary incontinence. At 15 months after surgical treatment, the patient presented with lung and bone metastases, and at 2 years after his initial operation, he had local recurrence.