# Infected left atrial myxoma with Streptococcus gordonii: case report and literature review

## TL;DR

A rare case of infected heart tumor caused by Streptococcus gordonii is reported, highlighting the importance of thorough diagnostic methods to avoid misdiagnosis.

## Contribution

Presents a novel case of infected left atrial myxoma confirmed using metagenomic sequencing and highlights diagnostic strategies for similar cases.

## Key findings

- Infectious left atrial myxoma can present with nonspecific symptoms, leading to delayed diagnosis.
- Streptococcus gordonii was identified as the causative agent using postoperative blood culture and metagenomic sequencing.
- Combining mNGS, PCR, and TEE is recommended for diagnosing febrile cardiac myxoma with suspected infection.

## Abstract

Cardiac myxoma is a relatively common type of benign heart tumor, but infectious myxoma is rare. The symptoms of non-infected cardiac myxoma and infected cardiac myxoma are similar and mostly nonspecific, which can easily lead to delayed diagnosis, missed diagnosis, and delayed treatment. A 57-year-old male patient presented with nonspecific systemic symptoms such as anorexia, fever, and cough, and was initially considered to have gastrointestinal disease or pulmonary infection. Preoperative bacterial culture was negative, and imaging features were consistent with cardiac myxoma. A small amount of vegetation was found attached to the surface of the tumor. Postoperative blood culture, surgical specimen culture, and postoperative blood metagenomic next-generation sequencing (mNGS) examination all showed positive results for Streptococcus gordonii, confirming the diagnosis of infectious left atrial myxoma. For patients with febrile cardiac myxoma, it is crucial to be vigilant against concurrent infections. Blood cultures should be performed before administering antibiotics. In cases where blood cultures are negative, a combination of mNGS, PCR, and transesophageal echocardiography (TEE) should be utilized for differential diagnosis, with particular attention paid to the characteristics of vegetations on the tumor surface.