A mature T-cell non-Hodgkin lymphoma, characterized by systemic disease and a polymorphous infiltrate involving lymph nodes and extranodal sites. The clinical course is typically aggressive. The disease is MONDO_0004977 (angioimmunoblastic T-cell lymphoma). Also known as: AILD, AILT, T-cell lymphoma, AILD type, angioimmunoblastic lymphadenopathy, angioimmunoblastic lymphadenopathy type T-cell lymphoma, angioimmunoblastic lymphadenopathy with Dysproteinemia, immunoblastic lymphadenopathy, lymphogranulomatosis X.