True about GIST all except: (A) Most common in duodenum, (B) Necrosis and ulceration present, (C) PET is used to assess response to therapy, (D) Well circumscribed
Answer is A. .GIST (Gastrointestinal stromal tumour) is rare but most common non epithelial small bowel tumours. * 25% of GIST occurs in small bowel (stomach - 50 to 60%). It is 0.2% of all GI tumours. * It is equal in both sexes * It arises from interstitial cell of Cajal. * More than 95% show c-kit (transmembrane receptor tyrosine kinase) mutation. * Many mesenchymal tumours of small bowel are now classified as GIST. GIST attains massive size when presenting clinically. * Palpable mass, compression, haemorrhage are the features. * CT is diagnostic. ref:SRB&;s manual of surgery,ed 3,pg no 812