Diagnostic Challenges of Left Atrial Myxoma Presenting With Systemic Inflammatory Symptoms, Thrombocytopenia, and Diffuse Lymphadenopathy.

backgroundLeft atrial (LA) myxomas are the most common primary cardiac tumors but may present with nonspecific systemic symptoms, making diagnosis challenging. CASE SUMMARY: A 40-year-old man with rheumatoid arthritis presented with 2 months of tachycardia, low-grade fevers, and exertional dyspnea. He trialed certolizumab without improvement in his symptoms. Multimodal imaging revealed a large LA mass with features concerning for tumor thrombus and malignant cardiac mass with notable diffuse lymphadenopathy. He underwent robotic-assisted resection of the mass and mediastinal lymph node biopsy. Pathology confirmed myxoma with reactive non-necrotizing granulomatous lymphadenopathy. Systemic symptoms resolved postoperatively. DISCUSSION: This case illustrates an atypical LA myxoma presentation with constitutional symptoms. Imaging findings were notable for lymphadenopathy, complicating the diagnosis. Multidisciplinary evaluation and advanced imaging were critical in management. TAKE-HOME MESSAGES: Myxomas may mimic malignant tumors when presenting with systemic inflammation, lymphadenopathy, and atypical echocardiographic findings. Robotic-assisted surgical resection is an effective, minimally invasive option for select cardiac tumors.