Custom Search




Pathology of Gastric Kaposi's Sarcoma 

Dr Sampurna Roy MD   








Kaposi's Sarcoma (KS) was described in 1872 by a Hungarian dermatologist, Moritz Kohn Kaposi, who was the first to identify five cases of "idiopathic multiple pigmented sarcomas of the skin".

In the stomach, Kaposi's Sarcoma can occur both as primary gastric tumour in AIDS and as part of systemic disease.

Kaposi sarcoma is the most common gastrointestinal malignancy in AIDS (seen in approximately 40% of patients) and is often asymptomatic.

The diagnosis of Kaposi sarcoma with a negative HIV test and positive test for HHV-8 should lead to the consideration of other causes such as iatrogenic or tumor-related immunosuppression (lymphoproliferative disorders).


Gastrointestinal involvement can precede, be synchronous, or develop without the appearance of the skin lesions.

Typically, gastrointestinal Kaposi's sarcoma is asymptomatic, but may present with gastric outlet obstruction, intussusceptions or bleeding.

The diagnosis is made by means of digestive endoscopy and biopsy.

The classical endoscopic finding is represented by subepithelial, reddish, ulcerative or non-ulcerative lesion.










Microscopic features are similar in each form of Kaposi sarcoma, with submucosal vascular spindle-shaped cells.

- It is classically characterized as spindle cell proliferation that forms irregular vascular channels or slits in the submucosal bowel layer.

- Associated with extensive red blood cell extravasation and hemosiderin-laden macrophage deposits which gives it a characteristic red to dark, bruise-like appearance. 

- Lymphoplasmocytic infiltration occur which can lead to tumour swelling and cause pain response.


The origin of the proliferating spindle cells in Kaposi sarcoma is uncertain.

These cells are currently believed to be derived from lymphatic endothelium.

Infection with HHV-8 is necessary for the development of Kaposi sarcoma in HIV patients.

It is considered the definitive cause of Kaposi sarcoma.

Over 95% of Kaposi sarcoma lesions, regardless of their source or clinical subtype, have been found to be infected with HHV-8. 












Human herpes virus-8 immunostain is positive



Differential diagnosis of Kaposi sarcoma in the stomach include non-Hodgkin's lymphomas, tumours of the gut with spindle-shaped cells such as leiomyomas, rhabdomyosarcomas, high-grade pleomorphic sarcomas, or gastrointestinal stromal tumours.

To make a diagnosis of KS, the presence of HHV8 is necessary and immunohistochemical testing is recommended for all specimens with spindle cell morphology.

HHV8 LNA is an immunomarker for this viral agent, and expression in spindle cell nuclei is considered to be 99% sensitive and 100% specific for Kaposi sarcoma.




Kaposi sarcoma involving the gastrointestinal tract. Gastroenterol Hepatol. 2010;6:459–462.


Alimentary tract involvement in Kaposi sarcoma: radiographic and endoscopic findings in 25 homosexual men. AJR Am J Roentgenol. 1982;139:661–666


Gastric Kaposi’s sarcoma. Radiologia Brasileira. 2015;48(3):196-197. doi:10.1590/0100-3984.2014.0033.


Gastrointestinal Kaposi’s sarcoma: Case report and review of the literature. World Journal of Gastrointestinal Pharmacology and Therapeutics. 2015;6(3):89-95.








Infectious Disease Online


Pathology Quiz Online 


Paediatric Pathology Online


Pancreatic Pathology Online




Endocrine Pathology Online


Eye Pathology Online


Ear Pathology Online


Cardiac Path Online


Pulmonary Pathology Online


Lung Tumour Online




Nutritional Pathology Online


Environmental Pathology Online


Soft Tissue Tumour Online


GI Path Online-India


Gallbladder Pathology Online


E-book - History of Medicine  


Microscope - Seeing the Unseen





Privacy Policy  

Advertising Policy

Copyright © 2018