Anatomy Cailage,cell junction,lymphoid and integumentary system 2243024f Which of the following statements concerning Hassall corpuscles is true? A They are located in the thymic coex of young individuals. B They are located in the thymic coex of old individuals. C They are derived from mesoderm. D They are located in the thymic medulla High-Yield Explanation Hassall corpuscles are epithelial reticular cells (derived from endoderm) found only in the medulla of the thymus.