The overall prognosis of type A thymoma is excellent, especially if it is completely resected. The 5-yr and 10-yr survival rates are reported to be around 90% and 80% respectively. Local recurrences and distant metastases can occur, but are exceedingly rare. Cases of thymic carcinoma arising in a background of type A thymoma have also been reported. In this image, the tumor is composed of anastomosing cords and trabeculae separated by cystic spaces. Several rosettes can be seen even at this magnification.