A Case of Incomplete-type Carney’s Triad With Stomach GIST Resistant to Tyrosine Kinase Inhibitors

Abstract

The coexistence of stomach GIST, pulmonary chondroma and extra-adrenal paraganglioma is known as Carney’s triad and this triad is common in young females. The developmental mechanism of GIST in Carney’s triad is different from common GIST; it has a dysfunction of succinate dehydrogenase. We report a rare case of incomplete-type Carney’s triad including only stomach GIST and pulmonary chondroma. The patient was a 19-year-old female. Multiple submucosal tumors in the pyloric antrum and multiple pulmonary tumors were found when she was 10 years of age, for which distal gastrectomy was carried out. Gastric tumors were diagnosed as wild-type GIST on the basis of histopathological examination results. Although imatinib was administered because the pulmonary tumors were considered metastatic, these pulmonary tumors grew slowly. We changed the type of tyrosine kinase inhibitor to sunitinib and regorafenib, but it did not work. Further histopathological evaluation of the resected gastric specimen revealed that the tumor has succinate dehydrogenase deficiency; thus, incomplete-type Carney’s triad was suspected and the pulmonary tumors were suspected as pulmonary chondroma. The pulmonary tumor in the right upper lobe increased in size, and right upper lobectomy was performed when she was 19 years of age. That tumor was diagnosed as pulmonary chondroma on the basis of histopathological examination results. If gastric GIST, lung or extra-adrenal tumors were found in a young patient, we should suspect Carney’s triad and treat the GIST as resistant to tyrosine kinase inhibitors.