Primary left atrial spindle cell sarcoma with low-grade malignant features mimicking recurrent myxoma: a case report

Primary cardiac spindle cell sarcoma is extremely rare, with atypical clinical manifestations and imaging features. This case report details a 54-year-old female patient with a primary cardiac spindle cell sarcoma of the left atrium, initially thought to represent a recurrent cardiac myxoma. Despite utilizing multiple imaging techniques, the patient's complex clinical history complicated the diagnostic process, and the correct diagnosis was established after surgical resection and pathological evaluation. This case highlights the diagnostic pitfalls associated with presumed recurrent cardiac myxomas and underscores the importance of careful pathological assessment and long-term surveillance, even in tumors with low-grade malignant features.