A Rare Case of Splenic Infarct Secondary to Mobile Cardiac Echodensity

Lambl's excrescences (LE) are mobile filiform lesions, mostly found on the left-sided heart valves. Histologically, they have a mesenchymal origin with a single endothelial layer. They have the potential to detach, resulting in catastrophic thromboembolic events. Their rarity often leads to them being misdiagnosed as vegetations of endocarditis with patients failing to improve on conventional therapy. A 48-year-old female with a history of hypertension presented to the Emergency Department with a one-week history of sharp left upper quadrant pain. She was vitally stable; the only lab abnormality was revealed to be a mildly elevated white cell count. CT abdomen revealed a splenic infarct involving 25% of the parenchyma. Patients had no history of abdominal trauma, coagulation disorders, exogenous estrogen use or IV drug abuse. Subsequent investigations failed to reveal any cause of hypercoagulability. An extensive cardiac workup revealed no arrhythmias, but transesophageal echocardiogram showed a mobile echo density on the ventricular side of the aortic valve attached at the coaptation zone, approximately 2.7 cm long and 0.1 cm wide, suggesting a very prominent Lambl's excrescence. In the absence of any other findings, the patient's splenic infarct was determined to be secondary to an embolic event from the aortic valve lesion. Rivaroxaban was initiated and the patient subsequently improved. Existing literature describes most LEs as being asymptomatic and discovered incidentally on echocardiograms. This case illustrates the need to develop a criterion for prompt identification of LEs and differentiating them from the vegetations of endocarditis. It also brings forth the question of prophylactic treatment of these lesions while highlighting the lack of guidelines regarding the management of embolic phenomena secondary to LE.