Case Presentation
A 58 years old female presented with a 2-month history of dyspnea on exertion (DOE) and two episodes of syncope was admitted on January 20th, 2020. The transthoracic echocardiography (TTE) showed a well-defined heterogeneous large round mobile mass with attachment to the atrial side of anterior mitral valve leaflet (AMVL) (29*20mm) suggestive of an atypical myxoma (Figure 1). In addition, the Ejection Fraction (EF) of 55%, severe mitral stenosis, severe mitral regurgitation, mild to moderate tricuspid regurgitation, and pulmonary arterial systolic pressure (PASP) of 42 mmHg were reported. The coronary angiography revealed normal epicardial coronary arteries. The brain CT and neurologic evaluation results were unremarkable. The patient became a candidate for surgical mass excision. On January 24th, the LA mass was removed completely (2*2.5 cm) and the mitral valve was replaced with the St. Jude Medical prosthesis due to the involvement of AMVL. The histopathological examination revealed diffuse fibrosis of mitral valve and cellular pleomorphism and high mitotic activity in the removed cardiac tumor. The evaluation of the surgical margin was not possible. Postoperative echocardiography revealed that the prosthetic valve had good leaflet motion with an acceptable gradient. The EF of 45%, Mild TR, and PASP of 28mmHg were also reported. No residual mass was detected. The patient was discharged thereafter on February 3rd.
Seventy-nine days later on April 22nd, 2020, the patient was readmitted with a 1-week history of dyspnea, palpitation, fever (body temperature of 38 °C), and sore throat. The time in therapeutic range assessment revealed that the international normalized ratio (INR) was acceptable during the mentioned period. In the emergency department, the TTE revealed fixation of one of leaflet of the prosthetic mitral valve with a mean pressure gradient of 12 mmHg, LVEF of 50%, moderate to severe TR and PASP of 63 mmHg. The mitral valve fixation was evident in the fluoroscopy. Laboratory examination demonstrated the high sensitive C-reactive protein (hs-CRP) of 9.9 mg/dl and white blood cell of 7100/μL with lymphocyte percentage of 18.8%. In the COVID-19 pandemic era, the focus was diverted to the thrombotic event of the prosthetic valve in the context of coronavirus infection and a spiral chest computed tomography (CT) scan performed to exclude the lung involvement. Although, no evidence of COVID-19 was detected in chest CT except mild pleural effusion, empiric antiviral treatment with hydroxychloroquine and azithromycin was initiated with respect to symptoms and high hs-CRP. The blood culture examination result was negative. The transesophageal echocardiography (TEE) revealed a very large non-homogenous LA mass (4*4cm) on the lateral LA wall that seemed to be an organized thrombus and restricted mitral valve leaflet motion (Figure 2). The reverse transcription-polymerase chain reaction test was negative for COVID-19. The patient was a candidate for surgical removal of the mass which was thought to be a thrombus (4*4 cm). Surgical resection of the mass was done on 27th April and the gross appearance was not compatible with thrombus or pannus. The postoperative echocardiography on May 2nd revealed LVEF of 40%, good leaflet motion of the prosthetic mitral valve. No visible residual mass was detected. The operative specimen was sent for pathological assessment. The Immunohistochemical stain raised the diagnosis of liposarcoma. The primary origin of the tumor approved, hence, the patient referred to the oncology department.