Primary Cardiac Sarcoma with Mitral Valve Invasion Complicated by Immune Thrombocytopenic Purpura: A Surgical Dilemma

Abstract Background Primary cardiac tumors are rare, comprising approximately 0.3–0.7% of cardiac tumors in autopsy series, and sarcomas are the most common primary cardiac malignancy. Most arise in the right atrium as angiosarcoma; left atrial undifferentiated high-grade sarcoma is distinctly uncommon and carries a poor prognosis with low rates of margin-negative resection. Concurrent immune thrombocytopenic purpura (ITP) introduces a management conflict between hemodynamic urgency and prohibitive bleeding risk for which guidance is limited. Case presentation A 63-year-old retired firefighter who participated in World Trade Center (WTC) rescue and recovery operations presented with decompensated heart failure. Imaging demonstrated a mobile left atrial mass prolapsing through the mitral valve with severe functional mitral stenosis (mean gradient 15 mmHg). Concurrently diagnosed ITP, confirmed by bone marrow biopsy, produced refractory severe thrombocytopenia (nadir platelet count 24×10³/µL) that repeatedly delayed operative intervention while the lesion was considered possibly thrombotic. After intravenous immunoglobulin and platelet transfusion raised the count to 60×10³/µL, urgent left atriotomy with tumor debulking and bioprosthetic mitral valve replacement was performed. Pathology showed a 6.2-cm high-grade spindle cell malignancy with 28 mitoses per 10 high-power fields, MIB-1 index approximately 50%, absent lineage-specific markers, and a positive posterior left atrial margin, consistent with primary undifferentiated cardiac sarcoma. He recovered and received adjuvant gemcitabine–docetaxel, but developed cerebral, osseous, pulmonary, and diffuse intra-abdominal metastases by 5–6 months and died shortly thereafter. Conclusions This case demonstrates how a competing hematologic diagnosis can delay resection of an obstructing cardiac malignancy, and how a microscopically positive margin portends rapid progression in undifferentiated cardiac sarcoma. The temporal relationship between the new ITP and the subsequent tumor diagnosis raises the possibility of a paraneoplastic mechanism, which has been described in roughly a quarter of reported cases of ITP associated with solid tumors as an antecedent finding. The patient's WTC exposure history is documented for completeness; malignancies in this population characteristically present at long latency, but no association between WTC exposure and primary cardiac sarcoma has been established, and attribution is not possible from a single case.