Colon tumor
Mesenchymal tumors
Leiomyoma

Author: Charanjeet Singh, M.D. (see Authors page)

Revised: 4 January 2017, last major update May 2012

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Leiomyoma [title] colon

Cite this page: Leiomyoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/colontumorleiomyoma.html. Accessed January 21st, 2017.
Definition / General
  • Benign, commonly presents as incidental tumor of muscularis mucosa of colorectum
  • 3% of GI leiomyomas occur in colon
  • 2/3 male, median age 62 years (range 38 to 85 years)
  • Benign, total excision is adequate treatment
Case Reports
Gross Description
  • 4 mm, usually rectosigmoid, firm, white and well delineated polypoid lesion
Micro Description
  • Well differentiated smooth muscle cells beneath mucosa that obliterates and merges with muscularis mucosa
  • May have significant atypia (symplastic leiomyoma)
  • Usually no mitotic activity, no necrosis
Micro Images

Images hosted on other servers:

Nature.com images:

Leiomyoma of muscularis mucosa

Symplastic leiomyoma

Positive Stains
Negative Stains
Additional References