BACKGROUND: The last decade brought a deeper understanding of @entity674 ( @entity674 ). The cell of origin is the pacemaker cell of Cajal which has an intermediate function between the autonomic nervous system and the smooth muscle cells of the gastrointestinal tract. These cells express @entity2467 / @entity2467 and less consistently @entity2280 . Based on this facts new diagnostic and therapeutic methods have been developed. In this study we applied the current immunohistochemical methods on @entity5 tissue previously diagnosed as @entity5 . METHOD: Histological specimens diagnosed as GISTs during 3 years (2005-2007) in the Department of Pathology, Tikur Anbessa Hospital, Addis Ababa, Ethiopia were reviewed and the available blocks were used for immunohistochemical assessment of @entity2467 and @entity2280 expression. RESULTS: Tumor specimens of 17 @entity1 were analyzed histologically. Most @entity5 were purely spindle celled (82%), the rest were mixed (spindle cells/epithelioid cells). Blocks of 14 @entity5 allowed immunohistochemical investigation. @entity2467 / @entity2467 positivity could be shown in 11 of 14 @entity5 , @entity2280 positivity in 9 of 13 @entity5 . In contrast to the reported cases from Western countries Ethiopian @entity1 with GISTs were younger, their @entity5 were larger and the most common sites were small and large intestine, not the stomach. CONCLUSIONS: GISTs became probably not more common but gave rise to increased interest during the last decade because of growing understanding of origin, behavior, and molecular mechanism. GISTs seen in Ethiopia differ from those reported in Western countries in age, size and location within the gastrointestinal tract.

XXXX in Addis Ababa, Ethiopia.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity5 :: ('MESH:D009369', 'Disease') :: ['stromal tumor', 'tumor', 'tumors'] @entity2467 :: ('3815', 'Gene') :: ['KIT', 'CD117', 'KIT/CD]17'] @entity2280 :: ('947', 'Gene') :: ['CD34'] @entity674 :: ('MESH:D046152', 'Disease') :: ['gastrointestinal stromal tumors', 'GIST']
@entity674 :: (MESH:D046152,Disease) :: ['Gastrointestinal stromal tumors']
