Thymic carcinomas are epithelial tumors of the thymus with clear-cut features of malignancy. They are usually not associated with myasthenia gravis and lack immature T lymphocytes. If lymphocytes are present, they are usually mature T (or B) cells. Thymic carcinomas are similar in appearance to corresponding tumors arising in other locations. The image shows non-keratinizing squamous cell carcinoma.