Pulmonary metastases from angiosarcoma: a spectrum of CT findings.

BACKGROUND: Though a few reports have summarized the computed tomography (CT) findings of pulmonary metastases from angiosarcoma, the detailed CT findings of cysts are not well known, except for their characteristic thin walls. PURPOSE: To retrospectively summarize the CT findings of pulmonary metastases from angiosarcoma, focusing mainly on the CT findings of cysts. MATERIAL AND METHODS: Thirty-three patients with pulmonary metastases from angiosarcoma were selected retrospectively. Two radiologists reviewed and assessed patients' chest CT images on a consensus basis for nodules, cysts, the CT halo sign, pneumothorax, pleural effusion, and enlarged lymph nodes. Cysts were also evaluated by wall thickness and smoothness, air-fluid levels, and vessels or bronchi penetrating the cysts. The relationship between cysts and pneumothorax was assessed using the Chi-square test. RESULTS: Nodules were found in 28 (85%) patients. Cysts were found in 19 (58%) patients; 17 had thin and smooth walls, 10 had thin and irregular walls, and four had thick and irregular walls. In addition, 12 patients showed vessels or bronchi penetrating the cysts, and six showed air-fluid levels. The CT halo sign, pneumothorax, pleural effusion, and mediastinal lymphadenopathy were seen in 19 (58%), 16 (48%), 26 (78.8%), and five (15.2%) patients, respectively. Pneumothorax occurred significantly more frequently in patients with cysts (P = 0.002). CONCLUSION: Cysts showed variability in their walls, and air-fluid levels and vessels or bronchi penetrating the cysts appeared to be characteristic findings, which may be useful for detection and accurate diagnosis in patients with pulmonary metastases from angiosarcoma.