A Case Report of primary cardiac intimal sarcoma presenting with atrial fibrillation and a Left Atrial Mass

Background Intimal sarcoma is an exceedingly rare type of primary cardiac tumour. It is characterized by poorly differentiated spindle-shaped cells that can mimic smooth muscle and is strongly associated with MDM2 genetic amplification. Owing to its rarity and non-distinctive histological features, diagnosis remains a significant challenge. Case summary In this case report, we describe a case of primary cardiac intimal sarcoma in a 37-year-old woman who presented with atrial fibrillation (AF) and a left atrial mass. Despite having a histological sample from an excised left atrial mass, the diagnosis was not made until she presented with back pain secondary to metastatic disease to the spine. Discussion Primary cardiac intimal sarcoma is an extremely rare diagnosis. The mainstay management of intimal cardiac sarcoma is aggressive surgical resection. Unfortunately, the prognosis of cardiac sarcomas remains very poor, with a mean survival between 3 months and 1 year. This case of cardiac intimal sarcoma highlights the difficulty in establishing a diagnosis, particularly given the unusual presentation of AF.