New insights into breast implant-associated anaplastic large cell lymphoma

PURPOSE OF REVIEW: Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a rare form of lymphoma arising adjacent to a breast implant. We aim to review the pathogenesis and clinico-biological features of BI-ALCL. RECENT FINDINGS: BI-ALCL is a new provisional entity in the 2017 updated WHO classification. Among several hypotheses, BI-ALCL development seems to be determined by the interaction of immune response related to implant products and additional genetic events. SUMMARY: BI-ALCL is an uncommon T-cell lymphoma which is increasingly diagnosed since its first description in 1997 with 500 estimated cases worldwide. Two BI-ALCL subtypes correlating with clinical presentation have been described. Although most BI-ALCL patients with tumor cell proliferation restricted to the periprosthetic effusion and capsule have excellent outcomes, other patients presenting with a tumor mass, may have a more aggressive disease. The pathogenesis of BI-ALCL remains elusive. It is postulated that local chronic inflammation elicitated by bacterial infection or implant products may promote the activation and proliferation of T cells. Additional genetic events resulting in the activation JAK/STAT pathway are also incriminated. Further investigations are needed to better characterize the pathogenesis of this disease in order to determine the potential risk to develop BI-ALCL after surgical implants.