Pediatric GIST: an evolving concept by Dr. Christina Antonescu
Understanding pediatric GIST may provide important clues by Jerry Call
Pediatric GIST can be divided into subgroups. These include Carney's Triad, Carney Stratakis Syndrome (this also has several other names), and Pediatric GIST. The common thread that links all of these subtypes seems to be that they all have some type of defect in the succinate dehydrogenase (SDH) protein. Several new names have been proposed that cover all of these types. These include pediatric-like GIST and SDH-deficient GIST.
The most familiar and perhaps the most common type of Pediatric GIST is when the patient only has GIST and no paraganglioma or chondroma. It most commonly affects girls between the ages of about 6 to 18 and almost always starts in the stomach.
The second well-known type of GIST affecting young people is called Carney’s Triad. It is named after Dr. P. Aidan Carney who first described it in 1977. Patients with Carney’s triad may have several different types of tumors including GIST, pulmonary chondroma, and/or functioning extra-adrenal paraganglioma. If any two of these tumors are present, a diagnosis of the "triad" can be made, particularly if age and sex factors are supportive. Some experts speculate that pediatric GIST's are simply an incomplete form of Carney's Triad and that some day these patients may develop chondromas and/or paragangliomas. This seems to be supported by the discovery that the underlying cause of all forms of pediatric-like GIST appears to be SDH deficiencies.
In 2002, Dr. Carney and Dr. Constantine Stratakis reported on a new syndrome that was similar to, yet distinct, from Carney’s triad. They had found 12 patients in 5 families with two parts of the “triad,” paraganglioma and GIST. Since this condition appeared to be inheritable and the “true Carney’s triad” did not, Carney and Stratakis concluded that this syndrome was different than Carney’s triad and called it “Familial Paraganglioma and Gastric Stromal Sarcoma” (GIST is sometimes called “Gastric Stromal Sarcoma”). The patients varied in age from 9 to 46 years old at diagnosis with 9 of the 14 patients under the age of 23.
When looking at multiple medical reports, it appears that there may one other type of Pediatric GIST. The youngest GIST patients of all may be born with GIST and need surgery soon after birth. This type of GIST, called "Neonatal or Congenital GIST", appears to affect both boys and girls (although girls are more common) and seems to start in the intestines instead of the stomach. We found 6 cases described as GIST in newborns, however there seems to be some doubt about whether or not these are really leiomyosarcomas or GISTs.