A 58-year-old, asymptomatic male presented to our hospital (Lishui Municipal Hospital, Lishui, China) for a physical examination. Written informed consent was obtained from the patient for the publication of the present study. The patient had no history of cigarette smoking, hypertensive disease, diabetes mellitus, hepatitis or tuberculosis. Routine blood, liver function, renal function, blood glucose, coagulation function and serum electrolyte test results were all within the normal range. Enhanced computed tomography (CT) (Philips, Brilliance ICT CP 200063) of the chest showed a 3.5 x 3.1-cm mass in the posterior mediastinum, and no other lesions were identified in the thoracic cavity (Figure 1).
A contrast-enhanced CT scan showed an enhanced mass with homogeneous internal density and clear tumor boundaries. A preoperative diagnosis of schwannoma was considered due to the enhanced CT features. Right-side video-assisted thoracoscopic surgery (VATS) was performed under general anesthesia due to the possibility that the mass was malignant. The 4th intercostal incision in the right axillary front was ~3 cm wide and was used as the operating hole; the 7th intercostal incision in the right midaxillary line was ~2 cm wide and was used as the observation hole. Intraoperatively, the tumor had clear boundaries, no invasion of surrounding tissues, and slight toughness. There was no evidence of intraspinal extension of the tumor. The boundary of the tumor was carefully separated with an ultrasonic knife, and the tumor was completely excised. The operation time was 20 min, and the bleeding volume was 20 ml. A chest tube was placed and removed 2 days after the operation. The surgical margins of resection were microscopically negative. Pathological examination revealed the presence of angiosarcoma (Figure 2A) and schwannoma (Figure 2B) components. Immunohistochemical staining for cluster of differentiation (CD) 31 (Figure 2C), CD34, EGR, vimentin, SOX-10 (Figure 2D) and S-100 was strongly positive. The patient rapidly recovered and was eventually discharged. Two months post-surgery, the patient returned for chest CT and had no evidence of tumor metastasis or recurrence (Figure 3 and see timeline in Figure 4).