"The overall incidence of GIST is uncommon when compared to gastrointestinal carcinoma, estimated at approximately 0.0015% 13. Small autopsy reports suggest the incidence of tiny ("
"Previously, these tumours have been referred to as leiomyoma, leiomyosarcoma ref, leiomyoblastoma, gastrointestinal autonomic nerve sheath tumour (GANT), and gastrointestinal pacemaker cell tumour (GIPACT) 21 as they were difficult to differentiate on histopathology until a characteristic expression of c-KIT (CD117) was identified 24."
"The overall incidence of GIST is uncommon when compared to gastrointestinal carcinoma, estimated at approximately 0.0015% 13. Small autopsy reports suggest the incidence of tiny ("
"KIT and/or DOG1 immunopositivity"
"SDHB gene mutation in SDH-deficient GISTs"
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"The vast majority of GISTs are sporadic; however, a minority (5-10%) occur in the following syndromes, usually as SDH-deficient GISTs 2,21:"
"GISTS are typically rounded and prone to frequent haemorrhage. Larger tumours may also demonstrate necrosis and cystic change 1,2. Size is variable, ranging from 1-30 cm 1."
"many KIT and PDGFRA wildtype GISTs have SDH subunit gene alteration (5-10%) leading to a distinct subtype, "SDH-deficient GIST", which more commonly presents as gastric tumours in younger patients (particularly children) and female patients 21"
"many KIT and PDGFRA wildtype GISTs have SDH subunit gene alteration (5-10%) leading to a distinct subtype, "SDH-deficient GIST", which more commonly presents as gastric tumours in younger patients (particularly children) and female patients 21"
"many KIT and PDGFRA wildtype GISTs have SDH subunit gene alteration (5-10%) leading to a distinct subtype, "SDH-deficient GIST", which more commonly presents as gastric tumours in younger patients (particularly children) and female patients 21"
"Specific appearances will vary according to location (see above) and size 24, but in general, these tumours appear as rounded soft tissue masses, arising from the wall of a hollow viscus (most commonly the stomach) with an endoluminal or exophytic growth. The usual growth pattern in the small bowel is exoenteric, with a large extraluminal component 19. Small GISTS tend to be round, while larger GISTs tend to be lobulated 24. Bowel obstruction is rare even with large tumours 19. Mucosal ulceration is present in 50% of cases 1 with large necrotic cavities communicating with the lumen also seen."
"Differentiating a benign from a malignant GIST radiologically is difficult 19. The diagnosis of malignant GIST requires histopathologic analysis, but certain characteristics suggest malignancy 15:"
"Differentiating a benign from a malignant GIST radiologically is difficult 19. The diagnosis of malignant GIST requires histopathologic analysis, but certain characteristics suggest malignancy 15:"
"The prognosis for resectable localised GIST is excellent, and more agents are becoming available for metastatic GIST. The main problem to overcome is secondary mutation following TKIs 25."
"The prognosis for resectable localised GIST is excellent, and more agents are becoming available for metastatic GIST. The main problem to overcome is secondary mutation following TKIs 25."
"rare in the remainder of the GI tract"
"lymphadenopathy uncommon for GIST"
"SDHB gene mutation in SDH-deficient GISTs"
"desirable: KIT or PDGFRA gene mutations in ~85%"
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"familial GISTs: KIT (more commonly) or PDGFRA germline mutations"
"KIT (~75%) or PDGFRA (~10%) oncogene gain-of-function mutations in encoding for type III receptor tyrosine kinases 21"
"many KIT and PDGFRA wildtype GISTs have SDH subunit gene alteration (5-10%) leading to a distinct subtype, "SDH-deficient GIST", which more commonly presents as gastric tumours in younger patients (particularly children) and female patients 21"
"Carney triad"
"In addition, extra-gastrointestinal GISTs are known to occur in the mesentery, omentum, and retroperitoneum 1,4 and are most likely to be recognised as metastasis or a detached primary lesion 21. Metastatic lesions (commonly liver 21) may also be seen in cases of malignant extra-gastrointestinal GISTs 7."
"In addition, extra-gastrointestinal GISTs are known to occur in the mesentery, omentum, and retroperitoneum 1,4 and are most likely to be recognised as metastasis or a detached primary lesion 21. Metastatic lesions (commonly liver 21) may also be seen in cases of malignant extra-gastrointestinal GISTs 7."
"GISTS are typically rounded and prone to frequent haemorrhage. Larger tumours may also demonstrate necrosis and cystic change 1,2. Size is variable, ranging from 1-30 cm 1."
"T2: high signal intensity solid component"
Expected headings
"Associations"
"Fluoroscopy"
"GISTs usually occur after 40 years of age, most commonly seen in older patients (median age 60-65 years) 1,21. They may present earlier and are often multiple in tumour syndromes (see below). There is a slight male predilection 21."
"They are believed to arise from the interstitial cells of Cajal 2,3 or their precursors; 95% stain positive for CD117 (c-KIT) and 70% for CD34 2. More recently, two predominant histological types have been described: spindle-cell GIST (mutated KIT or BRAF GIST, 70%) and epithelioid-cell GIST (mostly PDGFRA or SDH GIST, 20%). The remaining 10% have mixed morphology 25."
"The vast majority of GISTs are sporadic; however, a minority (5-10%) occur in the following syndromes, usually as SDH-deficient GISTs 2,21:"
"DWI/ADC: typical high DWI/low ADC signal; lower ADC values have been associated with high-risk tumours 24"
"Grading GISTs requires an assessment of both tumour size and mitotic index 3. Smaller lesions have less aggressive biological behaviour, as do stomach GISTs when compared to tumours elsewhere along the gastrointestinal tract 3. The risk of progressive disease depends on mitotic activity, size and anatomic site."
"The presence of necrosis, haemorrhagic and cystic change makes appearances variable, with small (5 cm) lesions having differing imaging characteristics 24:"