PMC5994268_01
Radiological examinations at diagnosis. A chest radiograph showed a faint infiltrative shadow in the left lower lung field (a). Contrast medium-enhanced chest computed tomography showed a large tumor in the left anterior chest wall (b). An enhanced mass in the right pulmonary artery (c) and small nodules in the right lung (d) were also found. Fluorodeoxyglucose (FDG)-positron emission tomography revealed positive FDG uptake in the pulmonary artery mass (e) and in the chest wall tumor (f).
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An 82-year-old man without any symptoms was referred to Hino Municipal Hospital, because of a faint infiltrative shadow observed in the left lower lung field on routine chest radiography (Figure 1(a)). Contrast medium-enhanced chest computed tomography (CT) revealed an enhancing tumor (58 x 33 mm in size) on the left anterolateral chest wall with destructive changes in the 6th rib bone (Figure 1(b)), corresponding to the abnormal shadow on the chest radiograph. In addition, a massive filling defect of the right proximal pulmonary artery was detected with pulmonary nodules in the right lung (Figures 1(c) and 1(d)). Fluorodeoxyglucose (FDG)-positron emission tomography (PET) showed a positive uptake of FDG to the pulmonary artery tumor (standardized uptake value, SUVmax 5.32), the chest wall tumor (SUVmax 9.56), and lung nodules (highest SUVmax 3.50) (Figures 1(e) and 1(f)), strongly suggesting a primary malignant tumor of the pulmonary artery, but not the thromboembolism.
Chronological progression of the tumors on chest computed tomography. Computed tomography cross sections of the right pulmonary artery and chest wall tumor levels were shown at 4 (a, b), 8 (c, d), and 9 months (e, f) from the initial visit. The tumor expansively occupied the entire lumen of the right pulmonary artery, and the chest wall tumor drastically enlarged over time, with a massive left pulmonary effusion appearing at 9 months.
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Chest CT showed expansive growth of the pulmonary artery tumor at 4, 8, and 9 months from the first visit to occupy the entire lumen, while the pulmonary trunk and left pulmonary artery were not involved (Figures 2(a), 2(c) and 2(e)). The chest wall tumor drastically expanded in 9 months (131 x 113 mm in size) from the subcutaneous soft tissue to the thoracic cavity (Figures 2(b), 2(d) and 2(f)).
Pathological findings at autopsy. Macroscopic observation of the transverse cut surface of the right pulmonary artery showed the vascular lumen filled with the solid tumor and secondary thrombus (a). Gross appearance of the chest wall tumor that is occupying the full thickness from the soft tissue through the thoracic cavity (b). The cut surface of the chest wall tumor appeared as a white-colored solid mass with central necrosis (c). The left 6th rib bone showed the tumor with complete osteolysis. Microscopic observation in the pulmonary artery tumor showed that the tumor was predominantly composed of pleomorphic, multinucleated round tumor cells with an incohesive nature (d). TC, thoracic cavity; SCST, subcutaneous soft tissue; PL, pleura; 6R, 6th rib bone.
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Macroscopic observation showed entire occlusion of the right pulmonary artery with a growing tumor and thrombus (Figure 3(a)). A large tumor (170 x 160 mm in size) occupied the left anterolateral chest wall from the subcutaneous soft tissue through the thoracic cavity with involvement of the parietal pleura (Figure 3(b)). Since osteolysis of the 6th rib bone was apparent at the center of the chest wall tumor (Figure 3(c)), it was speculated that the chest wall tumor was arising from a bone metastasis. The tumor was predominantly composed of pleomorphic, multinucleated round tumor cells with an incohesive nature and partly contained a hemangiopericytoma- or an angiosarcoma-like appearance, consisting of a pleomorphic sarcoma (Figure 3(d)).