Type AB Thymoma
An example of type AB thymoma where the two components (type A and type B) are intermixed. The tumor is composed of small spindle or polygonal epithelial cells with small round or oval nuclei, dispersed chromatin and inconspicuous nucleoli. The larger vesicular epithelial cells with prominent nucleoli characteristic of type B2 thymomas are not seen. Lymphocytes are scattered in the background.