Multifocal gastric gastrointestinal stromal tumors (GISTs) with lymph node metastases in children and young adults: A comparative clinical and histomorphological study of three cases including a new case of Carney triad

Background Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract usually occurring in the 6th to 7th decade of life, while their occurrence in children is rare (1-2%). Carney triad (CT), a non-hereditary association of gastric GIST with pulmonary chondroma and/or extraadrenal paraganglioma, is an even much rarer disease (to date ~120 cases reported worldwide) usually affecting young adult females. Pediatric GISTs differ from CT-associated GISTs solely by the absence of other components of the triad and are completely different from sporadic GISTs of the adult. Both, pediatric and CT-GISTs, metastasize frequently to regional lymph nodes (29%) and are usually wild type (WT) for common KIT-/PDGFRA mutations.