Colon tumor
Mesenchymal tumors
Kaposi sarcoma

Topic Completed: 1 February 2017

Minor changes: 9 July 2019

Copyright: 2003-2019,, Inc.

PubMed Search: Kaposi sarcoma colon

Raul S. Gonzalez, M.D.
Page views in 2019: 988
Page views in 2020 to date: 533
Cite this page: Gonzalez R. Kaposi sarcoma. website. Accessed July 7th, 2020.
Definition / general
  • Vascular malignancy caused by human herpes virus 8 (see topic in Soft tissue chapter)
Essential features
  • Vascular malignancy most often seen in AIDS patients with HHV8 infection
  • Rare in gastrointestinal tract
  • Most common gastrointestinal malignancy attributable to AIDS (Am J Gastroenterol 1991;86:715)
  • Currently rare; incidence decreased from use of HAART for AIDS treatment
  • HHV8 infection
Clinical features
Prognostic factors
Case reports
  • Chemotherapy and radiation preferred over surgery
Clinical images

Images hosted on other servers:

Kaposi sarcoma

Cherry red polyps on endoscopy

Gross description
  • Reddish brown to purple macules or polyps, typically 0.5 - 1.5 cm
Microscopic (histologic) description
  • Lamina propria based lesion composed of spindle cells with mild to moderate atypia, arranged in vague fascicles and separated by slit-like vessels
  • Extravasated red blood cells common
  • PAS positive, diastase resistant hyaline globules sometimes seen
Microscopic (histologic) images
Contributed by Raul Gonzalez, M.D.:

H&E, intermediate power

H&E, high power

Images hosted on other servers:

Low power

High power


Positive stains
Negative stains
Differential diagnosis
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