A 45-year-old man with fever, weight loss, pallor, and a diastolic murmur at the apex that changes with position most likely has which diagnosis?

A 45-year-old man with fever, weight loss, pallor, and a diastolic murmur at the apex that changes with position most likely has which diagnosis?

• A. Atrial myxoma
• B. Mitral stenosis
• C. Aortic regurgitation
• D. Adenocarcinoma of lung

Answer: (C)

A left atrial myxoma fits this presentation best. The constitutional symptoms—fever, weight loss, pallor—often come from inflammatory cytokines (like IL-6) produced by the tumor. A diastolic murmur at the apex that changes with position is the key clue: a pedunculated mass in the left atrium can intermittently obstruct the mitral valve during diastole as it moves with gravity or body position, causing a diastolic murmur that varies with posture. This mobility distinguishes it from a fixed valvular lesion like aortic regurgitation, whose murmur is typically an early diastolic decrescendo heard best along the left sternal border and does not classically change with posture. Adenocarcinoma of the lung can cause constitutional symptoms but wouldn’t produce a position-dependent diastolic murmur at the apex.

A left atrial myxoma fits this presentation best. The constitutional symptoms—fever, weight loss, pallor—often come from inflammatory cytokines (like IL-6) produced by the tumor. A diastolic murmur at the apex that changes with position is the key clue: a pedunculated mass in the left atrium can intermittently obstruct the mitral valve during diastole as it moves with gravity or body position, causing a diastolic murmur that varies with posture. This mobility distinguishes it from a fixed valvular lesion like aortic regurgitation, whose murmur is typically an early diastolic decrescendo heard best along the left sternal border and does not classically change with posture. Adenocarcinoma of the lung can cause constitutional symptoms but wouldn’t produce a position-dependent diastolic murmur at the apex.