A Potential Misdiagnosis in the COVID-19 Pandemic Era: A Case Report of Superimposed Thrombosis or Tumor Recurrence

Background The clinical manifestations of coronavirus disease 2019 (COVID-19) overlap with those of other disorders, especially cardiovascular disease. Case presentation We herein describe a 58-year-old woman who presented with syncopal episodes and dyspnea on exertion with a left atrial (LA) mass, scheduled for surgical removal and mitral valve replacement. Nearly 3 months later, the patient developed dyspnea, fever, and a sore throat, resulting in hospital admission with suspected COVID-19. During the diagnostic evaluation, a larger LA mass was detected. The mass seemed to be a COVID-19-induced organized thrombus with prosthetic mitral valve malfunction. Resection was, therefore, planned. An immunohistochemistry study revealed a liposarcoma. Conclusions The unusual early recurrence of liposarcomas and the misdiagnosis with COVID-19-induced thrombosis are the hallmark of the present case.