A new case of Carney triad: gastrointestinal stromal tumours and leiomyoma of the oesophagus do not show activating mutations of KIT and platelet-derived growth factor receptor alpha.

The Carney triad is a rare syndrome of unknown aetiology, with synchronous or metachronous appearance of rare neoplasms: gastrointestinal stromal tumours (GISTs), pulmonary chondromas and extra-adrenal paragangliomas. In most cases, the Carney triad is incomplete. The combination encountered typically, GISTs and pulmonary chondromas, was also seen in our patient, a 22-year-old woman. She was diagnosed with the triad after Billroth II gastrectomy for histologically proved gastric GISTs. The diagnosis of pulmonary chondromas was confirmed by transthoracic, computed tomography-guided needle biopsy. An oesophageal leiomyoma was resected 2 years after the initial diagnosis, on suspicion of paraganglioma. The clinical course of the patient has been uneventful since. The last follow-up was carried out 6 years after the initial diagnosis. On histological examination, the cells of gastric GIST were partly positive for CD34, whereas CD117 was expressed in all areas in variable intensity and S-100 protein was negative. The oesophageal tumour was classified as leiomyoma due to strong immunopositivity for smooth muscle actin and desmin, being negative for CD34 and CD117. Two different gastric GIST lesions as well as the oesophageal leiomyoma and normal tissue were analysed for activating mutations in common hot spots of KIT (exon 9 and 11) and platelet-derived growth factor receptor alpha (exon 18), but in all probes wild-type sequences were found. These results are in accordance with the first published analyses of GIST lesions from Carney patients.