Solitary Pulmonary Hematoma Radiographically Indistinguishable from Mediastinal Tumor

Abstract

Solitary pulmonary hematoma is a rare consequence of blunt chest trauma. Moreover, there has been no reported case of solitary pulmonary hematoma radiographically diagnosed as a posterior mediastinal tumor. We present the case of a 63-year-old man who was referred for an oval-shaped opacity at the left paraspinal area on a chest X-ray. Chest computed tomography showed a well-circumscribed posterior mediastinal tumor on the left paraspinal lesion with extrapleural sign and callus formation on the left ribs posteriorly (7^th to 11^th ribs). The tumor was thoracoscopically confirmed to be a subpleural pulmonary tumor of the left lower lobe, and wedge resection was performed. Histological examination confirmed the diagnosis of pulmonary hematoma. On reviewing the callus formation of the ribs, which was suggestive of rib fractures, the pulmonary hematoma was determined to be traumatic in origin. The postoperative course was uneventful. We reviewed a rare case of pathologically proven traumatic solitary pulmonary hematoma. The rarity of this case is enhanced because the hematoma initially appeared to be a posterior mediastinal tumor.

Figure 1

(a) Axial CT enhanced with intravenous contrast, mediastinal window. (b) Axial CT, pulmonary window. (c, d) Three-dimensional reconstruction using the CT of the chest (right ribs removed). Paraspinal oval mass in the lower thoracic spine measuring 20 mm in diameter. The capsule enhances slightly with contrast. The tumor is well-circumscribed without intraspinal extension. The callus formations in the posterior ribs (7th to 11th) can be observed, suggesting previous rib fractures (c, d; arrowheads).

Figure 2

(a) Intraoperative picture of the subpleural mass, with stapler applied. (b) Wedged-out section of the left lower lobe, showing the subpleural mass. (c) Microphotographs of sections stained with Victoria blue and HE stain. (d) High-power field of the rectangle in (c). The elastic layer of the visceral pleura is stained in blue. The hematoma was located inside the visceral pleura, indicating that the lesion is intrapulmonary. Scale bars in (c, d) are 2 mm and 250 μm, respectively.