Renal leiomyoma: gross pathology and histology

Case contributed by Dr Andrew Ryan


Incidental renal mass identified on CT abdomen

Patient Data

Age: 30
Gender: Female

Unfixed, bivalved right kidney specimen 

Macroscopic - Circumscribed, pale, rubbery, 100mm in diameter, in the upper pole of the right kidney. The tumour has a 'whorled' cut surface, reminiscent of a uterine fibroid.

Microscopic - Intersecting fascicles of smooth muscle cells with relatively uniform, 'cigar' shaped nuclei, eosinophilic cytoplasm and indistinct cell boundaries. Malignant features including mitotic activity, pleomorphism and necrosis are not seen.

Case Discussion

Leiomyoma is a benign tumour of smooth muscle. It is seen most commonly in the uterus (uterine 'fibroid'), gut and skin, but it is recognised to occur wherever smooth muscle is present.....which is virtually everywhere as smooth muscle is present in the walls of arterial and venous vessels.

Renal leiomyoma is an uncommon condition. Most present as small capsular/subcapsular tumours, with only rare lesions presenting as a clinically relevant mass. There is an even more uncommon malignant counterpart, renal leiomyosarcoma. 

Despite the characteristic macroscopic appearance, the diagnosis of leiomyoma is determined histologically, with intersecting fascicles of smooth muscle cells often with interspersed blood vessels. The tumour cells have uniform, spindled nuclei and the tumour lacks significant mitotic activity or necrosis. 

PlayAdd to Share

Case information

rID: 17638
Case created: 1st May 2012
Last edited: 14th Oct 2016
System: Urogenital
Inclusion in quiz mode: Excluded

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.