Radiological findings of renal leiomyomas: a report of five surgically confirmed cases.

BACKGROUND: To describe radiological features of renal leiomyomas.
METHODS: We retrospectively reviewed radiological findings of surgically confirmed renal leiomyomas in five patients. Three patients only underwent CT examinations, while two patients received both CT and MR examinations.
RESULTS: Six renal leiomyomas were found in the five patients, which located in the right kidney. Four tumors were at the periphery of the kidney, one tumor was in the renal parenchyma, and one tumor located in the renal pelvis. At plain CT scans, five lesions were homogeneous dense with three hyperdense and two isodense, while one lesion was heterogeneous dense. At MR imaging, one lesion was heterogeneous signal and two lesions were homogeneous signal. After i.v. contrast materials, all lesions demonstrated homogenous or heterogeneous enhancement which were lower than the renal cortex at the corticomedullary phase. A trend of continuous and homogeneous enhancement was observed in dynamic enhancement on CT and MR imaging.
CONCLUSION: Renal leiomyomas have some characteristic radiological findings, such as homogeneous density or signal peripheral mass with well-defined margins, less heterogeneous or homogeneous enhancement than adjacent renal cortex at the corticomedullary phase, a trend of continuous and homogeneous on later phase of dynamic scanning.