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 findings 1.
Renal leiomyomas are usually incidental findings. In symptomatic cases, these lesions can cause abdominal/flank pain and/or palpable mass 1.
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 fascicles 2.
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 specificity 1.
- can be either hypo- or hyper-vascular
- features indicative of malignancy (e.g. vessel encasement, renal vein invasion, arteriovenous shunting) are absent 1
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 invasion 1. Some suggest attenuation value, location and margins of the lesion can help to address the diagnosis of renal leiomyoma 2.
- 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