Anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK- ALCL) is an aggressive neoplasm of T-cell/null-cell lineage. The T-Cell Project is a global prospective cohort study that consecutively enrolled patients newly diagnosed with peripheral T-cell lymphoma, registered through a centralized computer database between September 2006 and February 2018. Of 1553 validated cases from 74 sites in 13 countries worldwide, 235 were reported as ALK- ALCL. The median age at diagnosis was 54 years (range, 18-89 years), with a male predominance (62%). Stage III to IV disease was identified in 71% of patients, bulky disease and bone marrow involvement were uncommon, and 66% of patients presented with a low (0-1) International Prognostic I...