Mediastinal Teratoma Causing SVC Compression

Teratomas are tumors consisting of tissue derived from all three germinal layers: the endoderm, mesoderm, and ectoderm. Almost all intrathoracic teratomas occur in the mediastinum, but they are rarely found in the lung. The authors present the case of a mediastinal teratoma abutting the right upper lobe, compressing the superior vena cava (SVC) and innominate vein.

The patient, a 17-year-old male, presented with chest pain. A chest x-ray, computed tomography of the chest with contrast, and a CT-guided biopsy of the mass were performed preoperatively. The chest CT revealed a mass on the right upper lobe invading the pericardium and compressing the SVC and innominate vein. Pathological analysis of the biopsy revealed a non-malignant mature teratoma with keratinizing squamous epithelium including adnexal structures (skin), respiratory epithelium, intestinal epithelium, pancreatic tissue, cartilage, adipose tissue, and involuting thymic tissue, within a fibrous stroma.

The patient was subsequently taken to the operating room for a right anterior VATS with partial resection of the pericardium. The mass was resected along with the right upper lobe and part of the pericardium. The right phrenic nerve, SVC, and innominate vein were carefully dissected to preserve the structures. The tumor was successfully separated from the surrounding structures and removed from the thoracic cavity. The resected specimen was 11 cm long and 9 cm wide. The postoperative course was uneventful.

This is a rare case of a mediastinal teratoma involving the right lung, pericardium, SVC, and innominate vein. The authors recommend complete resection of this type of tumor due to potential malignant transformation, potential rupture, and compression of the airway or major vessels.