An Endothelial-Lined Blood Cyst Arising from the Tricuspid Papillary Muscle: A Case Report.

Cardiac blood cysts are rare benign lesions typically observed in neonates and infants; persistence into adulthood is uncommon. Involvement of the tricuspid subvalvular apparatus is particularly rare. We report the case of a 47-year-old woman with a cardiac blood cyst arising from the tricuspid subvalvular apparatus. This case underscores the need to consider cardiac blood cysts in the differential diagnosis of right-sided intracardiac masses in patients with nonspecific symptoms and demonstrates the feasibility of valve- and subvalvular apparatus-preserving surgical excision.