Cancer, lymphoma, Hodgkin (adult): A type of lymphoma (cancer of the lymphatic system). The most common symptom of Hodgkin disease is a painless swelling in the lymph nodes in the neck, underarm, or groin. Hodgkin disease is diagnosed when abnormal tissue is detected by a pathologist after a biopsy of an enlarged lymph node. Treatment usually includes radiation therapy or chemotherapy. Regular follow-up examinations are important after treatment for Hodgkin disease. Patients treated for Hodgkin disease have an increased risk of developing other types of cancer later in life, especially leukemia.