Nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage: case report

An Unusual Case of Nonbacterial Thrombotic Endocarditis Attributable to Malignancy

Nonbacterial thrombotic endocarditis (NBTE), also known as marantic endocarditis, is a condition characterized by the deposition of thrombi and fibrin on normal or degenerated cardiac valves in the absence of microorganisms. We report a case of a 60-year-old male with nonbacterial thrombotic endocarditis found on transesophageal echocardiogram (TEE) after a normal TEE just one month prior. Our patient presented with abdominal pain associated with poor appetite and unintentional 20-pound weight loss for one month. Chest computed tomography revealed the presence of a mass-like opacification in the right lung middle lobe with moderate pericardial effusions. A biopsy of the mass confirmed malignancy consistent with lung primary adenocarcinoma. Subsequently, during hospitalization, the patient developed left lower extremity pain. Arterial ultrasound showed occlusion of the distal left popliteal artery for which he underwent thrombectomy of the left superficial femoral artery, balloon angioplasty of the left posterior tibial artery, and left popliteal artery. Repeat TEE during current hospitalization revealed a large 2 cm vegetation on the noncoronary cusp of the aortic valve. Studies for infective endocarditis were unremarkable. Subsequently, he was treated with aortic valve replacement and anticoagulation. After discharge, he returned with bilateral occipital infarcts four days later and expired.

Esophageal Adenocarcinoma Causing Nonbacterial Thrombotic Endocarditis

Nonbacterial thrombotic endocarditis (NBTE) is a rare condition that causes noninfectious vegetative lesions of heart valves. NBTE is generally seen in association with advanced malignancy. The patient in this case is a 54-year-old Caucasian male with a history of rate-controlled atrial fibrillation on rivaroxaban and morbid obesity post sleeve gastrectomy in 2021, who was admitted for atrial flutter. Transesophageal echocardiogram (TEE) cardioversion was planned due to difficulty in controlling the heart rate. During the procedure, cardioversion was aborted due to TEE findings of large mobile vegetation on the left atrial side of the posterior mitral valve leaflet. The patient was afebrile for the entirety of his 10-day hospital stay, and four sets of blood cultures were negative. Further workup with esophagogastroduodenoscopy (EGD) revealed a large partially obstructing ulcerated mass in the middle and lower third of the esophagus arising in the setting of Barrett's esophagus which was biopsy positive for esophageal adenocarcinoma. The patient was found to have advanced malignancy with metastases to the liver, adrenal glands, and perirectal lymph nodes. This case emphasizes the utilization of a TEE prior to cardioversion and also highlights the importance of EGD prior to and post gastric sleeve surgery to evaluate for esophageal cancer.

[An autopsy case after endovascular thrombectomy for cardioembolic stroke due to nonbacterial thrombotic endocarditis]

A 73-year-old women visited emergency department because of sudden right hemiplegia. She had a history of duodenum papilla cancer terminal stage and multiple liver metastasis. On admission, diffusion weighted images revealed high intensity area at left middle cerebral artery territory. In addition, 3D-TOF MRA depicted proximal part of the left internal carotid artery. We performed endovascular thrombectomy because low platelet count met contraindication of intravenous recombinant tissue plasminogen activator therapy. Although we could get partial recanalization of middle cerebral artery occlusion after thrombectomy, the patient eventually died due to multiple organ failure. Autopsy findings showed white thrombus on mitral valve and also left middle cerebral artery occluded by similar white thrombus without infective findings. The patient was finally diagnosed with nonbacterial thrombotic endocarditis due to white thrombus on the mitral valve. We should select appropriate mechanical thrombectomy devices with a case of cerebral infarction due to nonbacterial thrombotic endocarditis because its thrombus is often white thrombus and would be hard.

Nonbacterial Thrombotic Endocarditis in a Patient with Bowel Infarction due to Mesenteric Vein Thrombosis

Ante mortem cases of venous thrombosis in patients with nonbacterial thrombotic endocarditis (NBTE) have not yet been reported. We describe a rare case of NBTE in a patient with mesenteric vein thrombosis. A healthy 37-year-old man with abdominal pain and fever underwent emergency small bowel resection due to bowel ischemia resulting from mesenteric vein thrombosis. Transthoracic echocardiography revealed multiple mobile masses attached to the anterior leaflet of the mitral valves and their chordae tendineae. On suspicion of infective endocarditis, the cardiac masses were excised through open-heart surgery. However, pathologic reviews were compatible with NBTE. The patient was stable after the cardiac surgery and was treated with warfarin. Laboratory and imaging findings regarding his hypercoagulable condition were all negative.