Port-site implantation of Type A Masaoka Stage I thymoma after video-assisted thoracic surgery: a case report

A 60-year-old woman was referred to our hospital with an anterior mediastinal tumor measuring 3.5 cm in diameter on computed tomography (CT). We performed tumor resection by video-assisted thoracic surgery (VATS) with three ports. The final diagnosis was Type A Masaoka Stage I thymoma. On follow-up CT performed 36 months after the operation, two pleural tumors were detected at the port sites through which the forceps and ultrasonic scalpel had passed repeatedly during the operation. We therefore performed a second operation and enucleated the tumors while preserving the ribs. However, other tumor tissue was detected along the surgical marginal line during the pathological diagnosis after the operation. Surgeons should thus be aware that port-site recurrence can occur after VATS resection of Type A thymoma, despite its mild biological behavior. Wide resection of the chest wall is therefore recommended for operations of port-site recurrence after VATS thymectomy.