Dr. James Wilson is diagnosed with thymoma in the final season of House M.D.
Wilson’s diagnosis is revealed during the eighth season and becomes the central medical and emotional problem of the final episodes. Thymoma is a tumor arising from the thymus, an organ in the upper chest that is involved in immune-system development. In the show, Wilson’s disease is advanced and limits the time he has left.
The diagnosis changes House’s priorities. Rather than continuing to pursue the career and legal future expected after his actions, House arranges to spend Wilson’s remaining months with him. Their friendship, which has shaped the series from its beginning, therefore becomes the focus of the ending.
Thymoma is not the same as lymphoma, although both involve abnormal cells associated with the immune system and can affect the chest. Wilson is an oncologist, but his specialty does not make him immune to cancer; the storyline intentionally places the doctor in the position of a patient.