Cytological features of breast implant‐associated anaplastic large cell lymphoma in pleural effusion

: Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a very rare CD30-positive ALK-negative T-cell non-Hodgkin lymphoma included as a provisional entity in the 2017 WHO classification of lymphoid neoplasms. BIA-ALCL arises as proliferating cells over the surface of the implant. It is generally an indolent disease if confined within the fibrous capsule. In contrast, mass and/or infiltration beyond the capsule is much more aggressive. This report describes a case of infiltrative BIA-ALCL with massive pleural effusion containing hallmark BIA-ALCL cells showing the characteristic morphologic appearance of high-grade anaplastic lymphoma, CD30-positive but ALK-negative with variable staining for T-cell antigens. Detailed cytological features of BIA-ALCL in pleural fluid are described along with the results of a literature search performed for BIA-ALCL cases with pleural effusion. This report expands the spectrum of BIA-ALCL pathology to include chest wall involvement and pleural effusion.