The second well-known sub-type of GIST affecting young people is called “Carney’s Triad.” It is named after Dr. J. 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. It is important that patients less than 35 years of age who have any one of the three tumors be examined periodically in search of the others according to Dr. Carney.
By 1983, 24 cases of Carney's Triad had been reported and, by 1999, 79 cases had been reported. Carney’s triad affects mostly younger females but there is one report of an 84 year old man who was found to have Carney’s triad during an autopsy.
In 2002, Dr. Carney and Dr. Constantine Stratakis reported on a new syndrome that was similar to 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.
Increasingly, the link between Carney's Triad, Carney Stratakis Syndrome and pediatric-like GIST is believed to be an underlying defect in the succinate dehydrogenase protein (SHD). One distinction between Carney's Triad and Carney-Stratakis syndrome, seems to be that Carney-Stratakis syndrome is inheritable, and no family history has been noted in Carney's Triad. One possibility is that mutations or other defects in SDH may be different between the two. For example, germline mutations have been reported in SDHA in patients without a family history of GIST or Carney's Triad. It has been suggested (Wagner et al., 2012), that this germline mutation might be passed on, but that the "penetrance" of the mutation might be low (few affected members will develop the condition).
Although this website includes separate descriptions for Pediatric GIST and Carney's Triad, it is quite possible that the major difference between the two is that patients with Pediatric GIST have only developed one (GIST) of three possible tumor types (paraganglioma and chondroma are the other two). Thus patients with only pediatric-like GIST should be carefully monitored for all three tumor types.
To visit a site dedicated to Carey's Triad patients click here.