胃肠道间质瘤概念课件.pptVIP

胃肠道间质瘤概念 胃肠道间质瘤（Gastrointestinal Stromal Tumors, GIST）是一类起源于胃肠道间叶组织的肿瘤，占消化道间叶肿瘤的大部分。Mazur 等于1983 年首次提出了胃肠道间质肿瘤这个概念。 发病率及发病部位 Gastrointestinal stromal tumours (GISTs) represent 0.1-3% of gastrointestinal malignancies and 80% of gastrointestinal mesenchymal tumours The prevalence of the disease is estimated at 11 to 20 cases per million of population [1、2、3]. Sixty percent of GISTs present in the stomach, 30% in the small intestine, 5% in the colon and rectum and 5% in the oesophagus About 140 new cases are recognized in Greece every year; the mean age of diagnosis is 60 years and the male to female ratio approximately 1.4:1 [4]. GIST的症状、体征 The delayed diagnosis of stromal tumours, due to the lack of specific symptoms, results in 25% of patients presenting with metastatic disease. It often takes up to 6 months from the onset of initial symptoms to reach a diagnosis [5]. The most frequent manifestations of the disease include gastrointestinal haemorrhage, fatigue due to chronic anaemia, loss of appetite, weight loss, vom-iting, the presence of a palpable mass, and non-spe-cific abdominal pain. These symptoms appear due to displacement, rather than infiltration of nearby structures. A combination of symptoms is present in over 5% of patients [6、7] 病理诊断基因诊断 The kit protein is expressed in 90-95% of GISTs. This protein represents a transmembrane receptor that acts like a tyrosine kinase. In 5-10% of GISTs, mutations in Platelet-Derived Growth Factor Recep-tor (PDGFRα and PDHFRβ) are present that are mutually exclusive to the KIT mutations, while some GISTs have no detectable mutations in either receptor (wild-type GISTs) [8,9]. The expression ofCD34 is more frequent in gastric GISTs (85%), while it is positive in only 50% of GISTs that arise from the small intestine [10]. CD34 is universally expressed in oesophageal GISTs. Another recently recognized marker is cyclooxygenase 2 (COX-2) At least 80% of GISTs express this protein [11] 病理图示 The majority of stromal tum