Gastrointestinal stromal tumor, malignant
This is a malignant subtype of gastrointestinal stromal tumor
characterized by large size (diameter greater than 10cm) and more than 5 mitotic figures per 50 high power fields.
GISTs are very rare in the oesophagus and comprise 10–20% of the combined group of smooth-muscle and stromal tumours. Most are clinically detected as intraluminal distal oesophageal masses causing dysphagia, but externally extending oesophageal GISTs can manifest as mediastinal tumours.
Occasional examples have been incidentally detected during radiological screening or surveillance studies, and such tumours can have a good prognosis, an exception among this group of tumours, among which sarcomas predominate
Bosman FT, Carneiro F, Hruban RH, Theise ND (Eds.)
WHO Classification of Tumours of the Digestive System.
International Agency for Research on Cancer: Lyon 2010