A53-29 When the Liver Breaks the Heart: Obstructive Shock From a 12cm Hepatocellular Carcinoma

Abstract Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and the fifth most common cancer worldwide. Metastases most often involve the lungs, abdomen, and bones, whereas cardiac extension is rare, occurring in only 0.7-4.9% of cases, and carries a poor prognosis. Intracardiac involvement can produce obstructive physiology that mimics right heart failure and shock. A 78-year-old female with a history of type 2 diabetes, hypertension, hypothyroidism, and rheumatoid arthritis presented with new-onset tachycardia, dyspnea, hypotension, and progressive lower extremity edema. She reported an 80-pound unintentional weight loss over 1.5 years. Initial workup revealed poor perfusion and bilateral edema. CT chest demonstrated a 12.9 cm hepatic mass abutting the right atrium and superior vena cava with associated mediastinal shift. Biopsy confirmed poorly differentiated hepatocellular carcinoma with macrotrabecular pattern, and serum AFP was 527 ng/mL. Echocardiography showed pericardial effusion and compression of the right atrium with impaired diastolic filling. During hospitalization, the patient developed acute kidney injury, likely from impaired preload and superimposed contrast nephropathy, as well as a non-occlusive deep vein thrombosis. Cardiothoracic surgery advised transfer for potential resection with vena cava reconstruction and cardiopulmonary bypass, but given the extent of invasion, management focused on preload optimization and supportive care. This case highlights a rare presentation of HCC with direct cardiac involvement, resulting in obstructive shock. The macrotrabecular subtype of HCC is associated with aggressive vascular invasion, poor prognosis, and often linked to TP53 mutations or FGF19 amplification. Despite lacking cirrhosis or viral hepatitis, the patient’s history of nonalcoholic fatty liver disease may have contributed to malignant transformation. In the current literature, intracardiac extension of HCC has been reported in fewer than 5% of cases, most often as tumor thrombus rather than a massive compressive lesion. Reports combining macrotrabecular histology, right atrial compression, obstructive shock, and acute kidney injury are exceedingly rare. Upon review of current literature, this constellation of findings has not been clearly documented, making this case a novel contribution to the literature on intracardiac HCC. Intracardiac extension of HCC, though rare, can present with life-threatening hemodynamic compromise. This case emphasizes the importance of early recognition, vigilant monitoring of hepatic lesions, and multidisciplinary management. Its rarity in the literature underscores the need for clinicians to maintain a high index of suspicion when patients with large hepatic masses present with signs of right heart failure or obstructive shock. This abstract is funded by: None