Carney triad

Carney triad is an extremely rare syndrome characterized by the co-occurrence of three distinct tumor types: gastrointestinal stromal tumors (GISTs), pulmonary chondromas (benign cartilaginous tumors of the lung), and extra-adrenal paragangliomas (tumors arising from neural crest-derived cells). First described by J. Aidan Carney in 1977, the condition predominantly affects young women, with most cases presenting before the age of 35. The complete triad (all three tumor types) is present in only a minority of patients; most individuals develop two of the three tumors. Carney triad is distinct from Carney-Stratakis syndrome (dyad), which involves only GISTs and paragangliomas and has a known germline succinate dehydrogenase (SDH) subunit mutation with autosomal dominant inheritance. The body systems primarily affected include the gastrointestinal tract (most commonly the stomach, where GISTs cause bleeding, pain, or obstruction), the lungs (where chondromas are often discovered incidentally on imaging), and the autonomic nervous system (where paragangliomas may be functional, producing catecholamines and causing hypertension, palpitations, and sweating). Additional associated findings may include esophageal leiomyoma and adrenocortical adenoma. GISTs in Carney triad tend to be multifocal and may recur or metastasize, particularly to the liver and lymph nodes, though the clinical course is often indolent compared to sporadic GISTs. The etiology of Carney triad remains largely unknown. Unlike Carney-Stratakis syndrome, most cases of Carney triad are sporadic and do not follow a clear Mendelian inheritance pattern, though epigenetic alterations such as hypermethylation of the SDHC gene promoter have been identified in tumor tissue. Treatment is primarily surgical, involving resection of symptomatic or growing tumors. Imatinib and other tyrosine kinase inhibitors used for sporadic GISTs have shown limited efficacy in Carney triad-associated GISTs, which are typically wild-type for KIT and PDGFRA mutations. Long-term surveillance is essential due to the risk of metachronous tumor development and recurrence over many years.

Common questions about Carney triad