Spontaneous hemothorax: an unusual presentation of pulmonary metastasis from benign giant cell tumor of bone

Clinical History

We report a case with pulmonary masses in which sudden onset of hemothorax developed with acute respiratory failure. He twice underwent surgical resections for primary and local recurrent lesions. Chest radiography revealed massive right pleural effusion and a mass in the left lung base. Contrast-enhanced computed tomography was helpful in identifying a well-demarcated mass in the right lower lobe. Both masses displayed heterogeneous enhancement and wide contact with the pleura.

Imaging Findings

A 20-year-old man with chest and back pain, dyspnea, and palpitations was brought to the emergency department of our hospital in 2002. He had present with pathological fracture of the 4th cervical vertebra 5 years earlier, and benign giant cell tumor of bone had been diagnosed based on biopsy results. Surgical resection and bone grafting for the primary and local recurrent lesions had been performed twice, in 1997 and 1998. The interval between onset and local recurrence was 5 months. On admission, heart rate was 94 beats/min and blood pressure was 110/52 mmHg. Physical examination revealed pallor of the palpebral conjunctiva, mild tachycardia, tachypnea, and diminished respiratory sounds in the right lung. Arterial oxygen saturation in room air was decreased to 91%. Laboratory results yielded normal results except for mild hypoxemia. Anteroposterior spine chest radiography identified compression of the right lung with massive pleural effusion and a mass in the left lung base (Fig. 1). Thoracic drainage and continuous aspiration for the right-sided pleural effusion were started immediately. Since the aspirate was bloody, hemothorax was diagnosed. Contrast-enhanced computed tomography (CT) visualized a large amount of right pleural effusion, and an ovoid heterogeneously enhanced mass in each lung (Fig. 2). The left pulmonary mass was located dorsally in the lower lobe, and was well demarcated and in wide contact with the pleura, whereas the right pulmonary mass was buried in the collapsed lung, and was poorly demarcated from the surrounding tissue (Fig. 2). No calcification or cystic changes were observed in either mass. Angiography was performed to locate the source of hemorrhage, but no clear evidence of extravasation was seen. Unenhanced CT performed on hospital day 5 indicated some improvement of right hemothorax, with the mass located in the lower lobe in wide contact with the pleura (Fig. 3). Subsequent systemic examination identified no local recurrence or metastases to other sites. Thoracotomy for resection of the pulmonary metastases was performed 1 month after admission. The right thoracic cavity contained a massive old hematoma, with a mass of clotted blood present around the tumor, partially adherent to the pleura. Tumors in both lungs were turgid and tense, and bled easily. Pathologically, the resected tumors comprised proliferating ovoid- to spindle-shaped cells, intermingled with osteoclast-like, multinucleated giant cells showing no apparent atypism. Pulmonary metastases from giant cell tumor of bone was therefore diagnosed. The histopathological features of both tumors closely resembled those of the primary lesion. As of the last review, the patient remained in a disease-free state.

Discussion

Although giant cell tumor of bone is histologically classified as benign, metastasis to distant sites in the absence of sarcomatous transformation is known. Distant metastases occur frequently in the lung, but no cases of hemothorax due to pulmonary metastasis have previously been reported. Neoplastic diseases causing hemopneumothorax include primary benign lung tumors (chiefly vascular tumors), primary malignant lung tumors, and metastatic lung tumors. Metastatic lung tumors are commonly malignant, such as angiosarcoma, hepatocellular carcinoma, choriocarcinoma, and malignant hemangioendothelioma. However, benign tumors such as chondroblastoma have also reportedly displayed pulmonary metastases [1]. Bronchopleural fistula and lung parenchymal infarction distal to tumor emboli [2] in the case of malignant metastatic lung tumors, and secondary aneurysmal bone cysts [1] in the case of benign metastatic lung tumor such as chondroblastoma, have been involved in the development of hemopneumothorax. Tubbs et al. reported that, on chest radiography and CT, metastatic lesions from giant cell tumor of bone were round to oval, commonly appearing in the periphery and base of the lung as nodular opacities of homogeneous density [3]. In this case, tumors in both lungs showed similar CT features. In addition, marked contrast-enhancement of the tumors was observed, in addition to wide contact with the pleura. Most hemopneumothorax-causing metastatic tumors are hypervascular, and Hihara et al. [4] described contrast-enhanced CT findings similar to ours. The possibility of hemopneumothorax is thus worth remembering when the following combination of CT findings are noted with metastatic tumors: 1) wide contact between tumor and pleura; and 2) high contrast-enhancement of the tumor. Local recurrence is frequently seen immediately before or concurrent to detection of pulmonary metastases from giant cell tumor of bone [3,5]. Siebenrock et al. reported that the number of operations to control the primary lesion could represent a factor in the development of pulmonary metastases [5]. The relatively aggressive nature of giant cell tumor of bone may have been involved in the development of hemothorax in this patient. Pulmonary metastases from giant cell tumor of bone are commonly treated using surgical resection. Although recurrence after resection of pulmonary metastases is not uncommon [3,5], metastatic tumors grow relatively slowly, and frequently more than one surgical resection is performed [5]. A follow-up study for a mean of 11.9 years after diagnosis of pulmonary metastases from giant cell tumor of bone revealed that 79% of patients who underwent surgical resection only were free from disease by the end of follow-up, with a mortality rate from tumor of 17.4% [5]. Other studies have reported similar results [3], and pulmonary metastases from giant cell tumor of bone display a better prognosis than most metastatic lung tumors. This patient represents a case in which giant cell tumor of bone metastasizing to the lung caused hemothorax with acute respiratory failure. Although it may be rare, pulmonary metastases from giant cell tumor of bone should be included in the differential diagnosis of hemothorax.

Differential Diagnosis List

Final Diagnosis

Pulmonary metastases from benign giant cell tumor of bone

URL:	https://www.eurorad.org/case/3205
DOI:	10.1594/EURORAD/CASE.3205
ISSN:	1563-4086