METHODS
We have performed a search of the English literature, through PubMed and Medline, to identify all cases of BCs involving the MV, MV apparatus and tricuspid, aortic and pulmonary valves that have been so far reported. Articles in textbooks and meeting abstracts were excluded, as well as cases included in general reviews of cardiac tumors or clinical reports, when detailed clinical and pathological information on BCs, when present, was lacking. Cases of valvular cysts but with uncertain histological diagnosis were excluded. The reference sections of pertinent articles were also evaluated as well as personal files and the archives of journals available on the CTSNet website. All reported cases observed in the pediatric population were excluded, considering only those occurring in patients ≥18 years of age.
Main terms used in the literature search, alone or in combination, were: intracardiac cyst, valvular cyst, blood cyst, blood-filled cyst, pedunculated cysts, mitral valve, mitral valve apparatus, mitral valve leaflet, tricuspid valve (TV), papillary muscle, chordae tendineae, aortic valve (AV), pulmonary valve (PV), semilunar valve, valve cusps, atrio-ventricular valve, semilunar valve.
Approval by the Ethical Committees was not required for this kind of study, as well as informed patient consent, provided that all relative data were treated anonymously.