title: A case of inverted left atrial appendage mimicking a tumor.
abstract: We report a rare case of an inverted left atrial appendage without prior cardiac surgery. A left atrial mass was incidentally found during routine echocardiography in a 19-year-old man with mitral valve prolapse. Echocardiography revealed a hyperechoic mass in the left atrium, and a neoplastic lesion could not be excluded. On magnetic resonance imaging (MRI), this mass consisted of fat tissue that showed continuation to epicardial fat, indicating an inverted left atrial appendage mimicking a tumor in the left atrium. When a mass in the left atrium is observed on echocardiography, there are several differential diagnoses, including thrombus, vegetation, and intra-atrial neoplasms such as myxomas. Recently, several studies reported cases with inverted left atrial appendages mimicking tumors in patients after cardiac operations. We present a case of inverted left atrial appendage without any prior cardiac surgery. Cardiac MRI was highly useful to obtain the final diagnosis of inverted left atrial appendage.
authors.affiliation: First Department of Internal Medicine, Mie University School of Medicine, 2-174 Edobashi, Tsu 514-8507, Japan. motoyasu@clin.medic.mie-u.ac.jp
authors.forename: Munenobu
authors.initials: M
authors.lastname: Motoyasu
authors.forename: Hajime
authors.initials: H
authors.lastname: Sakuma
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Katsuya
authors.initials: K
authors.lastname: Onishi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Okinaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Isaka
authors.forename: Kan
authors.initials: K
authors.lastname: Takeda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D020517:Atrial Appendage / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology*; D003937:Diagnosis, Differential; D004452:Echocardiography; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000473:pathology*; D006338:Heart Neoplasms / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011859:Radiography