Gross appearance of a thymoma showing distinct lobulation. There is focal cystic change in the larger nodule.
Thymoma
Close-up of the cut surface of thymoma. Note the sharp lobulation induced by the fibrous bands. The pointed ends of some of the nodules are particularly typical of this entity.
The tumor is invasive and shows foci of yellow necrosis.
Thymic carcinoma invading surrounding tissues
Benign spindle cell (Medullary) thymoma
The tumor shows spindled or elongated epithelial cells that resemble those normally populate the medulla
This is one of the most common thymoma subtypes.
Mixed Thymoma (epithelial & spindle cells)
Epithelial thymoma
There is an even proportion of neoplastic epithelial cells and non-neoplastic lymphocytes.
Invasive thymoma
Minimal invasion of the mediastinal fat beyond the thick fibrous capsule of a thymoma.
Thymic carcinoma (Squamoid)
This tumor, which is predominantly composed of atypical neoplastic thymic epithelial cells, is known as well-differentiated thymic carcinoma. Note the presence lymphocytes.
