A 34-year-old female patient from China was admitted after the identification of a mass in the left posterior mediastinum persisting for over a month. The patient reported that a routine chest computed tomography (CT) disclosed a mass measuring approximately 67×42×65 mm in the left posterior mediastinum. The patient experienced shortness of breath after tensive activities without fever, cough, sputum, chest tightness, pain, nausea, vomiting, night sweats, or fatigue. CT scans revealed the feeding vessels of the mass closely associated with the descending aorta. The patient was admitted for further medical intervention. Upon admission, the patient exhibited alertness, orientation, no significant chest tenderness, clear bilateral breath sounds, with reduced sounds on the left side.
Thorough preoperative assessments were conducted, revealing no notable abnormalities in routine blood tests. Pulmonary function tests showed obstructive ventilatory impairment at GOLD Stage 2, with a forced expiratory volume in one second (FEV1) of 1.92L (70.8% predicted) and maximum voluntary ventilation (MVV) of 66.6% predicted. Contrast-enhanced CT scans revealed a lobulated soft tissue density, approximately 39×60mm in size, near the left side of the spine, exhibiting notable enhancement and close proximity to the descending aorta (Fig. 1). Bilateral pleural effusion was also observed. The patient chose surgical intervention, refusing both vascular preoperative angiography and biopsy.
Following the exclusion of surgical contraindications, thoracoscopic surgery was conducted through a 5cm incision along the anterior axillary line at the fifth intercostal space. Intraoperatively, the mass was located in the left posterior thoracic cavity, situated below the spine and above the diaphragm. It exhibited partial cystic characteristics, was encapsulated, and closely associated with the thoracic aorta and posterior chest wall (Fig. 2B). To enhance the procedure, an additional 1.5cm-incision was made at the seventh intercostal space along the posterior axillary line for thoracoscopy. Upon meticulous exploration, the mass exhibited rich vascularity (Fig. 2A). Two veins from the abdominal cavity entered the lower pole (Fig. 2E-F), and the tortuous vein converged from the superior pole, draining into innominate vein (Fig. 2D). Additionally, two arteries originated directly from the descending aorta (Fig. 2C), and several veins drained into the intercostal veins (Fig. 2G). All feeding vessels were ligated using vascular clips and silk threads. Subsequently, the tumor was dissected along its margin. The wound was meticulously managed for hemostasis. Owing to the size and vascularity of the mass, approximately 600ml of blood loss was recorded during the 4-hour surgery. The patient exhibited a satisfactory postoperative recovery, as demonstrated by X-ray revealing expanded lungs. Follow-up over six months revealed no signs of recurrence or metastasis.
Pathological examination confirmed an isolated fibrous tumor with a gray-white, tough, solid appearance. Immunohistochemical staining demonstrated positive expression of CD34 (Fig. 3B), STAT6 (Fig. 3C), and Catenin in tumor cells, while P63, S-100, and cytokeratin (CK) exhibited negative results. The Ki-67 index was approximately 5%.