case_images: PMC11835092_01
case_images: Transesophageal echocardiography of the heart. (A and B) A hypoechoic mass was detected in the right atrium near the opening of the superior vena cava, about 43 x 26 mm in size, with clear boundary, irregular shape, and heterogeneous internal echo.
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case_images: F1
case_images: The transesophageal echocardiography further revealed a low echo mass in the right atrium, precisely located at the right atrial roof near the opening of the superior vena cava. The mass exhibited a wide base and an approximate oval shape, leading to considerations of thrombus or space-occupying lesion (Fig. 1).
case_images: Enhanced CT scan of the chest. (A) After the injection of contrast agent, the right atrium showed a low-density filling defect with an unclear boundary and a lower CT value than the surrounding atrial cavity. (B) The lesion was markedly heterogeneous enhanced on delayed scan, and the maximum cross section was about 3.9 x 2.4 cm. CT = computer tomography.
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case_images: F2
case_images: The CT value following contrast agent administration exhibited a lower intensity compared to the surrounding atrial cavity, and the lesion demonstrated evident heterogeneous enhancement on delayed scan, indicative of a space-occupying lesion (Fig. 2).
case_images: Cardiac MRI examination of the 4-chamber cardiac position. (A) T1WI showed isointensity of the right atrial lesion. (B) The right atrial lesion showed slightly hyperintensity on T2WI. (C) DWI showed high signal intensity in the right atrial lesion. (D) The lesions were significantly enhanced on T1WI + C. The dimensions measured approximately 5.6 x 2.4 cm. MRI = magnetic resonance imaging.
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case_images: F3
case_images: Additionally, there was a reduction in the size of the right atrial cavity, and delayed scans indicated significant enhancement changes within the lesion (Fig. 3), suggestive of a right atrial neoplasm.
case_images: Intraoperative picture. (A) The tweezers indicate the tumor, which has invaded almost the entire right atrium, and the tumor is close to the right atrioventricular groove. (B) Medial view of tumor.
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case_images: F4
case_images: Careful examination of the tumor revealed no invasion into the right coronary artery and tricuspid annulus (Fig. 4).
case_images: Pathology and immunohistochemistry. (A) Postoperative pathological angiosarcoma of right atrial mass (HE x 100 times). (B) Tumor tissue immunohistochemical CD31 positive (x100 times).
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case_images: F5
case_images: Immunohistochemical findings exhibited positive staining for CD31, ERG, focal EMA, Vimentin, CD34 vessels; negative staining for CKAE1/AE3, CK8/18, CK5/6; and a Ki-67 proliferation index of 65% (Fig. 5).