Severe Functional Tricuspid Regurgitation Masked by Annular Deformation in Primary Cardiac Lymphoma

BACKGROUND: Primary cardiac lymphoma can regress rapidly with chemotherapy; however, release of tumor-related annular compression may paradoxically alter valvular geometry and unmask regurgitation. CASE SUMMARY: A 79-year-old woman with clinically diagnosed primary cardiac diffuse large B-cell lymphoma involving the right heart developed severe tricuspid regurgitation 4 months after chemotherapy despite marked tumor regression. Serial echocardiography demonstrated relief of extrinsic tricuspid annular compression, subsequent annular enlargement and flattening, and leaflet malcoaptation without progressive intrinsic leaflet or subvalvular abnormalities. Symptoms improved with intensified diuretic therapy. DISCUSSION: This case suggests that tumor regression likely contributed to compression release-related annular remodeling, thereby unmasking severe functional tricuspid regurgitation. In cardiac tumors adjacent to valvular structures, serial imaging should evaluate annular geometry as well as tumor burden. TAKE HOME MESSAGES: Rapid regression of a cardiac tumor adjacent to a valve may paradoxically unmask or worsen valvular regurgitation by altering annular geometry. Serial echocardiography should assess annular configuration and leaflet coaptation, not only tumor burden, in patients with cardiac tumors involving valvular structures.