Gastrointestinal Stromal Tumor (GIST)

Gastrointestinal Stromal Tumor (GIST) is a type of growth that develops in the digestive system, most commonly in the stomach or small intestine. It arises from special cells in the walls of the gastrointestinal tract called interstitial cells of Cajal, which help control digestion. These tumors can vary in size and may cause symptoms like abdominal pain, bleeding, or a feeling of fullness. Some GISTs grow slowly and cause few problems, while others can be more aggressive and spread to other parts of the body. Diagnosis often involves imaging tests and tissue sampling to confirm the nature of the tumor. Treatment depends on the tumor's size, location, and whether it has spread. Understanding this condition helps explain symptoms related to the digestive system and guides appropriate medical care.

Gastrointestinal Stromal Tumor (GIST) is a mesenchymal neoplasm of the gastrointestinal tract arising from the interstitial cells of Cajal or their precursors. It is characterized by activating mutations in the KIT or PDGFRA genes, leading to constitutive activation of receptor tyrosine kinases and uncontrolled cellular proliferation. GISTs most commonly occur in the stomach (60%) and small intestine (30%), with less frequent involvement of the colon, rectum, and esophagus. Clinically, GISTs may present with gastrointestinal bleeding, abdominal pain, or a palpable mass, but some remain asymptomatic and are found incidentally. Histologically, they show spindle cell, epithelioid, or mixed morphology and express CD117 (c-KIT) and DOG1 on immunohistochemistry. The clinical significance lies in their potential for malignant behavior, including local invasion and metastasis, primarily to the liver and peritoneum. Risk stratification is based on tumor size, mitotic rate, and location, guiding prognosis and management.