GIST is one of three types of tumors comprising the Carney triad; the other two triad components are functioning extra-adrenal paragangliomas and pulmonary chondromas. Paragangliomas are rare tumors arising from neural-crest-derived chromaffin cells. These cells are located in certain areas of the head, neck and torso. Paragangliomas may raise blood pressure by producing adrenalin. Pulmonary chondromas (also rare) are benign cartilaginous lung tumors. They are sometimes known as chondromatous hamartomas. The GISTs in Carney Triad are usually inside the stomach.
Carney triad is an extremely rare syndrome, with fewer than 30 cases reported with all three tumors present, and fewer than 100 incomplete cases having two of the three tumor types present (usually the GISTs and chondromas). Carney triad predominately affects females (over 80% of cases), with the first tumor often appearing in the teenage years. The first tumor identified is most often gastric GIST. Because there may be a time lapse of many years between identification of the first tumor and appearance of the second type of tumor, all pediatric GIST cases should be considered as potential Carney triad cases. The gastric GISTs in Carney triad are typically multifocal (displaying more than one tumor nodule). They are usually of epithelioid cell type. The prognosis is better than in adult GIST, with a slow course of progression even after metastasis has occurred. However, many patients require repeated surgeries for recurring tumors.
Recently Carney (1999) described two other conditions (adrenocortical adenoma and esophageal leiomyoma) as additional components occurring in some triad patients.
GIST samples from two Carney triad patients have been tested for mutations (Diment et al, 2004; Knop et al, 2006) but none were found. Gleevec had no apparent effect on liver metastases in the patient described by Diment et al. However, Delemarre et al (2006) did report a case for whom imatinib (Gleevec) was effective. The mutation(s) responsible for Carney Triad have not yet been identified.
You can read Dr. Carney's memoir about discovering Carney Triad on our site under Ask the Professional.
By special permission of Dr. Carney, Dr. Appleman, and the Mayo Clinic Proceedings, the following two papers about Carney Triad are available on the GIST Support International website:
J. Aidan Carney (1999). Gastric stromal sarcoma, pulmonary chondroma, and extra-adrenal paraganglioma (Carney Triad): natural history, adrenocortical component, and possible familial occurrence. Mayo Clinic Proceedings 74(6): 543-552.