Type AB Thymoma : Definition

Comments:
Type AB thymoma is composed of lymphocyte-poor type A areas containing neoplastic spindle epithelial cells (which appear as lighter pink areas in this image) and lymphocyte-rich type B areas (which appear as darker blue). The two areas may be sharply demarcated or may be intermixed. Type AB thymoma is one of the most common subtypes and makes up about 28% of all thymomas.