Dr. Lotus Alphonsus

Could it be a polyp, maybe a lipoma, or a leiomyoma?

This is the challenge with gastrointestinal stromal tumors, or GIST.

They are masters when it comes to mimicking, blending in, and deceiving.

They were misdiagnosed, misunderstood, and mistreated for years, but then, in the early 2000s, GIST quietly made medical history because it responded almost miraculously to a pill.

This was one of the first times a solid tumor melted away with targeted therapy, sparking a revolution in oncology.

Today, our patient has a gastrointestinal stromal tumor, and you are the doctor.

Welcome to The Internet Work, a podcast written by medical residents meant to serve you better on the wards and on call.

Today's episode is titled The Gist of It All.

Gifts originate from the intestinal cells of Cajal.

These are the pacemaker cells regulating peristalsis in the GI tract.

Most GISTs arise due to mutations in one of two genes.

Approximately 75-80% of GISTs are associated with the KIT proto-oncogene.

Another 5-10% are associated with the PDG-FRA gene.

Both these mutations lead to activation of tyrosine kinase signaling pathways.

The unregulated growth leads to neoplastic transformation and tumor formation.

The most common sites are the stomach, about 60%, and the small intestine, about 30%.

However, it can present in other areas as well, such as the colon, rectum, or very rarely in the esophagus.

Gists are mesenchymal in origin, but they are often mistaken for adenocarcinoma or leiomyosarcomas until immunohistochemistry reveals the truth.

Gists are usually discovered incidentally during imaging, endoscopy, or surgery for other unrelated conditions.

When they do present, the symptoms depend on the tumor size and its location.