Background <p>Left atrial appendage aneurysm (LAAA) is a rare cardiac anomaly with fewer than 200 cases reported until 2022 and no established diagnostic or management guidelines. This updated systematic review synthesizes all cases published between January 2023 and July 2025, highlighting clinical patterns, imaging findings, and evolving treatment approaches.</p> Methods <p>Following PRISMA 2020 and JBI 2020 criteria, English-language case reports and series meeting predefined quality thresholds (≥ 75% or ≥ 70%) were retrieved from PubMed, Scopus, and Google Scholar. Two independent reviewers extracted demographic, imaging, and outcome data using standardized forms. Quantitative analysis was limited to descriptive summaries using SPSS v24, while qualitative synthesis consisted of a structured narrative and thematic organization of case-level clinical, imaging, and management data using NVivo 14.</p> Results <p>Twenty-five patients from 24 studies were included (median age 36 years, range 5 days–78 years; 56% male). Palpitations and dyspnea were the predominant symptoms; atrial arrhythmias occurred in 52%. Echocardiography (92%) served as the initial modality, while CT (84%) and MRI (28%) defined structure and thrombus. Histopathology indicated chronic fibrotic degeneration. Surgical or interventional management was performed in 79% and conservative therapy in 21%. Innovative procedures, thoracoscopic resection, RF ablation, and device-based WATCHMAN FLX occlusion, achieved excellent short-term outcomes. Overall survival was 88%, with fatalities mainly in neonatal or elderly patients.</p> Conclusions <p>LAAA is a progressive dysplastic aneurysm presenting across ages. Multimodal imaging defines risk and guides individualized management. Emerging minimally invasive and device-based strategies complement conventional surgery, signaling a therapeutic shift. Ongoing data collection and imaging-pathology correlation are needed for standardized care of this rare entity.</p>