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.
Although for the vast majority of patients with Carney triad the causative defect(s) remain(s) unknown, testing for SDHA, SDHB or SDHC variations should be offered, as carriers may develop isolated paragangliomas/pheochromocytomas and occasionally other tumors.
Collectively, these data suggest epigenetic inactivation of the SDHC gene locus with functional impairment of the SDH complex as a plausible alternate mechanism of tumorigenesis in CT.
Eighty-seven PHEOs/PGLs (48 sporadic/23 SDHx/7 von Hippel-Lindau/5 REarranged during Transfection/3 neurofibromatosis type 1/1 hypoxia-inducible factor 2α), one SDHD variant of unknown significance, and two Carney triad (CTr)-related tumors were analyzed by HRMAS-NMR spectroscopy.
Eighty-seven PHEOs/PGLs (48 sporadic/23 SDHx/7 von Hippel-Lindau/5 REarranged during Transfection/3 neurofibromatosis type 1/1 hypoxia-inducible factor 2α), one SDHD variant of unknown significance, and two Carney triad (CTr)-related tumors were analyzed by HRMAS-NMR spectroscopy.
Germline and/or somatic aberrations of SDHA occur in a small subset of KIT/PDGFRA WT GISTs, outside the Carney's triad and are associated with loss of both SDHA and SDHB protein expression.
Germline and/or somatic aberrations of SDHA occur in a small subset of KIT/PDGFRA WT GISTs, outside the Carney's triad and are associated with loss of both SDHA and SDHB protein expression.
Loss of SDHB immunohistochemical expression can be useful for differentiating pulmonary chondromas from hamartomas, and potentially identifying patients with Carney triad.
Other tumors (outside CT and CSS) that have SDH deficiency are associated with increased methylation of the entire genome, but only in CT there is site-specific methylation of the SDHC gene.
Our objective was to investigate the possibility that patients with CT and/or their tumors may harbor mutations of the SDHB, SDHC, SDHD, KIT, and PDGFRA genes and identify any other genetic alterations in CT tumors.
The above have clinical implications (i) for patients with GISTs that are cKIT- and PDGFRA-mutation negative: these tumours are usually resistant to treatment with currently available tyrosine kinase inhibitors and may be part of a syndrome such as CT or CSS; and (ii) for patients with an inherited PGL syndrome, family history should be explored to identify any other tumours in the family, and in particular other endocrine lesions and GISTs.