ALK and peripheral T-cell lymphoma, not otherwise specified: However, external validation data for other T-cell lymphomas, such as adult T-cell leukemia/lymphoma, enteropathy-associated T-cell lymphoma (types 1 and 2), peripheral T-cell lymphoma, NOS, ALCL, ALK-negative, primary cutaneous gamma-delta T-cell lymphoma, and angioimmunoblastic T-cell lymphoma, showed a high range of presumptive diagnostic error rates from 10.9 to 100.0%.