2. Case report
A 60-year-old previously healthy Japanese man was referred to our
hospital for evaluation of anemia and pericardial effusion 13 months
before his death. The patient presented with no apparent symptoms at
that time. Pericardiocentesis was performed, and the effusion was
evaluated cytologically; however, no atypical cells could be identified,
and the etiology of the effusion was undefined. The patient ignored
follow-up visit appointments; but returned six months later to the
hospital with dyspnea, bloody sputum, edema, and anorexia. A blood
examination showed severe anemia (red blood cells, 1.64 ×
106/μL; hemoglobin, 3.3 g/dL), and echocardiography
revealed a mass in the right atrium (Figure 1). Computed tomography (CT)
disclosed multiple nodules in the lungs and the liver. As a biopsy of
the cardiac mass was technically difficult, a transbronchial biopsy of
the lung mass was performed; but the biopsied specimen did not contain
any atypical cells. Hematological malignancies were suspected because of
progressive anemia and the presence of human T-cell leukemia virus type
1 antibodies. The patient was treated with THP-COP (pirarubicin,
cyclophosphamide, vincristine, and prednisolone) and mogamulizumab under
the provisional diagnosis of adult T-cell leukemia/lymphoma.
Nevertheless, the patient’s general condition worsened progressively.
The anemia and edema continued to progress, and the pleural effusion
increased. The patient died of respiratory failure 13 months after his
initial admission to the hospital.
The patient was autopsied eight hours after his death. The heart adhered
to the pericardium (Figure 2A), and the pericardial cavity contained 130
mL of sanguineous pericardial effusion. In the right atrium, a dark-red
colored, approximately 7 × 4-cm-sized multilobulated tumor arose from
the atrial wall and filled the dilated atrial lumen (Figure 2B). The cut
surface of the tumor was sanguineous and solid, intermingled with
necrotized and calcified foci (Figure 2C). The muscular layer of the
right atrial wall was completely replaced by the tumor. The tumor
penetrated the pericardium and directly invaded the right lung (Figure
2D). Histologically, the tumor consisted of atypical cells with oval- to
spindle-shaped nuclei, which formed vague capillary channels containing
red blood cells (Figure 3A). Tumor cells protruded into the atrial
cavity, forming papillary structures (Figure 3B). Exfoliated clusters of
tumor cells were also observed in the atrium. The tumor cells were
immunoreactive for CD31 (Figure 3C) and FLI1 but were negative for
podoplanin (D2-40 antibody). Therefore, we diagnosed the lesion as an
angiosarcoma. The tumor cells penetrated the pericardium and visceral
pleura of the right lung and directly invaded the pulmonary parenchyma.
Multiple metastases were identified in the lungs, liver, spleen,
jejunum, and skin. In the jejunum, the metastatic nodule resulted in
intussusception. In the bilateral lungs, tumor emboli were formed in the
pulmonary arteries, and intra-alveolar hemorrhage and bronchopneumonia
were present. The central nervous system was not examined.