Renal leiomyomas are benign tumours of the kidney originating from smooth muscle cells of the renal capsule, pelvis, calyces or blood vessels.
There is a 4-5.5% prevalence based on autopsy findings1.
Renal leiomyomas are usually incidental findings. In symptomatic cases, these lesions can cause abdominal/flank pain and/or palpable mass1.
At macroscopic examination, leiomyomas are typically well-demarcated, solid , firm nodules with rare calcifications and cystic changes, without necrosis.
Microscopically, spindle cells with few nuclear polymorphisms and no mitotic activity are arranged in intersecting fascicles2.
Diagnosis in based on histological analysis.
Ultrasound may display a solid or cystic mass and allow for identification of a plane between the tumour and kidney, but has very poor specificity1.
Angiographic appearance can be either hypo- or hyper-vascular and features indicative of malignancy, such as vessel encasement, renal vein invasion or arteriovenous shunting, are absent1.
Computed tomography scanning provides improved anatomic definition and reveals well-circumscribed margins, a capsular/subcapsular or peripelvic origin, minimal parenchymal distortion, and no evidence of extra-renal invasion1. Some suggest attenuation value, location and margins of the lesion can help to address the diagnosis of renal leiomyoma2.
- 1. Andreoiu M, Drachenberg D, Macmahon R. Giant renal leiomyoma: a case report and brief review of the literature. Can Urol Assoc J. 2011;3 (5): E58-60. Free text at pubmed - Pubmed citation
- 2. L. E. Derchi, N. Grenier, G. Heinz-Peer, V. Dogra, F. Franco, G. A. Rollandi &C. Deminiere (2008) Imaging of Renal Leiomyomas, Acta Radiologica, 49:7, 833-838