title: Retrovesical mass in a 57-year-old man.
mesh_terms: D006393:Hemangiopericytoma / Q000175:diagnosis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed