**Core Concept**
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, arising from the interstitial cells of Cajal or their precursors. They are characterized by mutations in either the KIT or PDGFRA genes, leading to uncontrolled cell proliferation.

**Why the Correct Answer is Right**
GISTs are known for their distinct genetic profiles, with KIT mutations being more common in gastric GISTs and PDGFRA mutations being more common in small intestinal GISTs. The KIT protein is a tyrosine kinase receptor that, when mutated, can lead to constitutive activation and uncontrolled cell growth. The PDGFRA gene encodes a receptor for platelet-derived growth factor, and mutations in this gene can also lead to GIST development.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because GISTs can occur in any part of the gastrointestinal tract, not just the stomach. While gastric GISTs are more common, they can also occur in the small intestine, colon, and rectum.

**Option B:** This option is incorrect because GISTs are typically benign, but they have the potential to become malignant. Malignant GISTs are characterized by their ability to invade and metastasize to other parts of the body.

**Option C:** This option is incorrect because the treatment of GISTs often involves surgical resection, but also may include targeted therapy with tyrosine kinase inhibitors such as imatinib. Imatinib is a specific inhibitor of the KIT and PDGFRA tyrosine kinases, and is used to treat GISTs with these mutations.

**Option D:** This option is incorrect because the histological appearance of GISTs can vary widely, and they may resemble other types of tumors such as leiomyomas or schwannomas. However, GISTs typically have a characteristic spindle cell morphology and are positive for CD117 (c-KIT) and CD34.

**Clinical Pearl / High-Yield Fact**
GISTs are often difficult to diagnose, but they can be identified by their characteristic spindle cell morphology and positive staining for CD117 (c-KIT) and CD34. It's essential to consider GIST in the differential diagnosis of any gastrointestinal tumor, especially in patients with a history of gastrointestinal symptoms.

**Correct Answer:** Not provided in the original question. Please provide the correct options for a complete explanation.