Fig. 5

Stroma sparse group of TETs. Top row: Type B1 thymoma shows an abundance of immature lymphocytes (20X), and the lymphocytic population obscures the epithelial cells (100X). Middle row: Type B2 thymoma has a less dense lymphocytic infiltrate as comparison with type B1 thymoma (20X), and the epithelial cells are easily identifiable (100X). Bottom row: Type AB thymoma shows variable combination of lymphocyte-poor area (type A-like, *) and lymphocyte-rich area (type B-like, **) (20X & 100X)