Current diagnostic practice for ALK-negative anaplastic large cell lymphoma (ALCL) does not always reflect the rapidly expanding understanding of its biologic and molecular heterogeneity. In ideal practice, hematopathologists and clinicians should be able to integrate morphology, immunophenotype, and newly recognized molecular alteration, such as DUSP22, TP63, and JAK/STAT pathway abnormalities, when evaluating cases and discussing their significance. Because ALK-negative ALCL can overlap morphologically and immunophenotypically with other CD30-positive lymphoid and non-lymphoid neoplasms, there remains a meaningful gap between current recognition of these newer diagnostic utilities and their consistent application in routine practice.

The literature and disease classification in this area have evolved quickly, with newer data refining the molecular subtypes and biologic spectrum of ALK-negative ALCL. Many practicing pathologists, hematologists, and oncologists trained before these updates were widely incorporated into routine teaching materials, so awareness and practical application may lag behind the evidence base. This activity is necessary to synthesize what specifically should be addressed in current practice, including updated molecular features, diagnostic pitfalls, differential diagnosis, and the clinical relevance of newer subclassification concepts, so that learners can more confidently close the identified knowledge and competence gaps.