Unusual Displacement of Urinary Bladder by a Dilated Rectosigmoid Colon on Bone Scintigraphy.

A 7-year-old boy with chief complaint of chronic pelvic pain was referred to our nuclear medicine department for bone scintigraphy. The images showed a focus of radiotracer activity in the right side of pelvic cavity, which is further confirmed as urinary bladder by single-photon emission computed tomography (SPECT) and delayed images. Because of high possibility of mass effect in pelvic cavity, pelvic magnetic resonance imaging (MRI) was performed, and it revealed an unusual dilatation of rectosigmoid colon with no evidence of pelvic mass.