An anterior mediastinal tumor containing suture thread after a right middle lobectomy of the lung; a case report

An anterior mediastinal tumor containing suture thread was suspected histologically of being an old hematoma.A 53-year-old male was found to have an abnormal shadow in the right chest field on a routine examination. He had had a right middle lobectomy for pulmonary tuberculosis 32 years previously. A block resection of the mass was carried out for the anterior mediastinal tumor. The tumor measured 6. 5 × 4. 5 ×3. 2 cm, and had a fibrous capsule surrounding a necrotic and hemorrhagic mass. Histological examination of the specimen revealed an old hematoma containing suture thread with calcification. There was no evidence of inflammation, tuberculosis or neoplasm.We considered that the tumor might be the result of chronic bleeding of unknown etiology, related to the former operation.