Kidney tumor

Benign adult tumors


Topic Completed: 1 March 2016

Minor changes: 15 March 2021

Copyright: 2003-2021,, Inc.

PubMed Search: Kidney [title] leiomyoma

Pallav Gupta, M.D.
Page views in 2020: 1,130
Page views in 2021 to date: 1,455
Cite this page: Gupta P. Leiomyoma. website. Accessed December 6th, 2021.
Definition / general
  • Benign tumor of smooth muscle usually located in the cortex or rarely in the renal capsule (Acta Radiol 2006;47:752)
Essential features
  • Circumscribed lesion composed of benign spindle shaped smooth muscle cells
  • Found in 4.2% to 5.2% of autopsies
  • Breakpoints in the q13-15 region of chromosome 12 have been seen in leiomyomas and congenital mesoblastic nephroma
  • Tsujimura and colleagues suggested an association between tuberous sclerosis and renal leiomyomas (Urol Int 1996;57:192)
  • Krishnan and colleagues have showed an association between Epstein-Barr virus infection and renal leiomyomas in immunocompromised patients (J Urol 1999 Jan;161:212)
Clinical features
  • Usually an incidental finding
  • Most occur in adults; tumors of significant size are more common in young women
Prognosis and treatment
  • Renal leiomyomas do not have aggressive behavior and do not metastasize
  • The prognosis following surgery is excellent without recurrence
Case reports
Gross description
  • White or red peripheral lesion, well defined, with a solid aspect and elastic consistency
Gross images

AFIP images

Firm circumscribed tumor

Images hosted on other servers:

28 cm tumor

Microscopic (histologic) description
  • Well circumscribed lesion of benign smooth muscle cells
  • Features suggestive of leiomyosarcoma include mitoses, nuclear pleomorphism, necrosis
Microscopic (histologic) images

Images hosted on other servers:
Missing Image


Differential diagnosis
  • Angiomyolipoma:
    • Usually vascular and lipomatous components
    • Positive for melanocytic markers
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