Cardiac Angiosarcoma with Unusual Cytologic Features Causing Cardiac Tamponade in a Young Adult Patient

Abstract Introduction/Objective Cardiac angiosarcoma is a rare endothelial malignancy with poor prognosis, frequent metastasis, and short median survival of only a few months. The disease has a wide age spectrum and can occur in young adult patients. The cytological diagnosis of cardiac angiosarcomas is challenging as cases are rare and its cytology is not extensively described or reported in literature. Here, we describe a rare case of cardiac angiosarcoma with unusual cytologic features. Methods/Case Report Our patient is a 30 year old male presenting with three days of worsening dyspnea and palpitations and was discovered on ultrasound to have large pericardial effusion compressing the right ventricle and causing cardiac tamponade. CT/MRI imaging revealed a 4.5 x 4.3 x 2.6 cm mass inside the right ventricle with extra- cardiac invasion through the pericardium and into the anterior mediastinum. Pericardiocentesis yielded 1.5 liters of hemorrhagic, brown, pericardial fluid with elevated LDH and protein levels. Cytology of the pericardial fluid revealed numerous tumor cells occurring singly or in monolayered, acinar clusters or cohesive spheres containing amorphous, eosinophilic cores made of collagen as evidenced on trichrome stain. The tumor cells possessed hyperchromatic, irregular, variably sized nuclei, prominent nucleoli, and cytoplasmic vacuoles. The tumor cells were positive for vimentin, CD31, and CD34, and showed high Ki67 proliferation index > 50%. A catheter-mediated biopsy of the right ventricular mass revealed spindled and epithelioid tumor cells strongly positive for CD31, CD34, and vimentin, focally positive for Factor VIII and AE1/AE3, and showing high Ki67 proliferation index of roughly 50%. The cytological, histological, and immunohistochemical findings were most consistent with cardiac angiosarcoma as the diagnosis. The patient eventually developed worsening chronic left chest pain and expired from cardiac arrest six months after his diagnosis. Results (if a Case Study enter NA) NA Conclusion We report a rare case of cardiac angiosarcoma with unusual cytologic features, manifesting as acinar clusters and cohesive spheres with collagenous cores that are not typical of malignant endothelial neoplasms. Currently there are no effective, standardized therapies that can significantly prolong survival for this malignancy, and treatment is often palliative. The cytological diagnosis of cardiac angiosarcoma is challenging given the rarity of this disease and the paucity of literature describing its cytology.