Incidental Cardiac Fibroma in a Young Soldier: Exercise Authorization and Graded Fitness-for-Duty Determination

Cardiac fibroma is the second most common primary cardiac tumor in children but is uncommonly diagnosed in adulthood, where it is usually discovered incidentally. Neither the 2020 ESC guidelines nor the 2025 AHA/ACC scientific statement on sports cardiology specifically address exercise recommendations for this entity, and data on fitness-for-duty determination in military personnel with incidental cardiac tumors are nonexistent. We report the case of a 25-year-old active-duty soldier in whom routine electrocardiographic screening prompted transthoracic echocardiography that unexpectedly identified a well-circumscribed intramyocardial mass (20 × 20 mm) in the basal interventricular septum. Cardiac MRI demonstrated features highly consistent with a fibroma. Comprehensive assessment including repeated exercise stress testing, exercise echocardiography with hemodynamic evaluation, and Holter monitoring was unremarkable. After multidisciplinary evaluation, a conservative strategy was adopted. Recreational sports participation was authorized based on a structured, stepwise risk assessment. Full operational fitness was restricted, but a graded approach to military duties was implemented, acknowledging that fitness-for-duty in military populations is not a binary determination. Three-year follow-up confirmed clinical and imaging stability. This case adds to the limited evidence guiding exercise and fitness-for-duty decisions in adults with cardiac fibroma.