What is Surgery – Gist tumor

​What is Surgery – Gist tumor
 
STOMAL TUMORS OF THE GASTROINTESTINAL SYSTEM
 
DESCRIPTION
Interstitial cells of Cajal, pacemaker cells linked with Auerbach's plexus that coordinate peristalsis, may be the source of gastrointestinal mesenchymal tumours. Exhibit a range of malignant potential, from very minimal risk to downright dangerous.
 
AETIOLOGY
Mutations in KIT (75–80%, CD117) or PDGFR- (platelet derived growth factor receptor alpha, 5–10%) cause constitutively active receptor tyrosine kinase signalling pathways and cellular proliferation.
 
RISK FACTORS/ASSOCIATIONS
 Carney's triad , neurofibromatosis type I, and familial GIST syndrome are risk factors.
 
EPIDEMIOLOGY
Annual incidence ranges between 11 and 15 per million, with a frequency of 129 per million. Males and females have a wide age range, however 75 percent are above 50 years old (median 58 years).
 
HISTORY
Endoscopy/imaging/laparotomy may reveal an asymptomatic/incidental finding. Gl bleeding (70 percent), abdominal pain/bloating (57 percent), bowel blockage (30 percent), satiety/weight loss (22 percent), palpable mass (13 percent), and, more infrequently, rupture are some of the other symptoms.
EXAMINATION
Findings are dependent on the location, size, and difficulties. The stomach (50 percent), small bowel (25 percent), colon/rectum (10 percent), mesentery, omentum, and retroperitoneum (10 percent), and oesophagus (10 percent) are the most common sites
 
INVESTIGATIONS
Endoscopy: Biopsies are frequently negative unless 'inkwell' biopsies are conducted, which may reveal a submucosal tumour. Endoscopic ultrasound reveals a hypoechoic mass adjacent to the muscularis mucosa or propria, which is usually hypoechoic. Because of the risk of tumour rupture and dissemination, perioperative or percutaneous biopsy is not often indicated.
CT abdomen and 18FDG PET scans are used for imaging. To pinpoint the tumor's location.
 
Immunohistochemistry: KIT (95%) and CD34 positive (60-70 percent ).
 
MANAGEMENT
 For non-metastatic GISTs, surgical resection is the treatment of choice. Complete excision has a high possibility of being successful and should be undertaken if at all possible.
 
Lymphadenectomy is not suggested on a regular basis. For small-to-intermediate tumours, laparoscopic excision can be utilised.
 
Neoadjuvant and adjuvant imatinib clinical trials are currently underway. Advanced disease : Imatinib inhibits the receptor tyrosine kinases KIT, PDGFRA, and BCR-ABL by binding competitively to the ATP binding site. It is used to treat advanced/metastatic GISTs. Disease control was achieved in up to 85% of patients, with a median survival time of more than 36 months. With the course of the disease, dose escalation or surgical resection or radio frequency ablation of liver metastases may be considered.
 
Sunitinib is used to treat advanced instances that have failed to respond to imatinib treatment.
 
 COMPLICATIONS
 During surgery, extreme caution should be exercised to avoid tumour rupture and seeding. Local and haematogenous spread modes exist. Metastases to the liver or transperitoneum are common, as are lung/bone metastases in advanced instances; lymph node metastases are uncommon.
 
 
PROGNOSIS
 Almost all GISTs have the potential to become cancerous. Site, with gastric cancer having a better prognosis than small bowel cancer, size (>5–10 cm, greater malignant potential), mitotic activity (>5 mitoses per 5O HPFs), and resection completeness are also prognostic markers.