title: Hyperdense renal masses: a CT manifestation of hemorrhagic renal cysts.
abstract: Eleven patients with sharply circumscribed round to ovoid renal cysts measuring 70-90 H on CT are reported. The cysts were hyperdense on unenhanced scans, measuring 30-60 H greater than the adjacent parenchyma, and either hypodense, isodense, or hyperdense on enhanced scans. Four patients had polycystic kidney disease; of the other 7 patients, the cysts were cortical in 6 and parapelvic in 1. Eight patients had a solitary cyst and 3 had multiple cysts. Sonography demonstrated internal echoes and/or lack of increased through-transmission in 6 patients. Pathological analysis was available in 6 cases and indicated a benign, hemorrhagic renal cyst. This hyperdense CT appearance is characteristic of some hemorrhagic renal cysts, though differentiation between benign and malignant cysts requires cyst puncture and/or surgery.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging; D006801:Humans; D007672:Kidney Cortex / Q000000981:diagnostic imaging; D052177:Kidney Diseases, Cystic / Q000000981:diagnostic imaging*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D007682:Kidney Pelvis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D007690:Polycystic Kidney Diseases / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography