Flow cytometry of ALK-negative anaplastic large cell lymphoma of breast implant-associated effusion and capsular tissue.

Background: Anaplastic large cell lymphoma (ALCL) of the breast capsule is a rare lymphoma involving capsular tissues and/or effusions associated with breast implants. While several studies have detailed the histological and immunohistochemical features of these tumors, no study has yet described flow cytometry features of the neoplastic cells of this entity. Here, we report two cases from our institution in which multi-parametric flow cytometry was performed. Methods: The immunophenotype of ALCL in association with breast implant was evaluated by flow cytometry. Results: We show that much like CD30+ tumor cells of classical Hodgkin lymphoma (CHL) and ALCL of non-breast implant tumors, the neoplastic cells of this entity can be readily identified by flow cytometry. The neoplastic cells of both cases were largely devoid of T-cell antigens, but had expression of weak CD15, strong CD30, and expression of CD40. These results are correlated with routine morphologic and immunohistochemical analysis, supporting the flow cytometry immunophenotype. Conclusions: Flow cytometry can aid in the diagnostic evaluation of effusions or tissue samples in association with breast implant/prostheses. © 2014 Clinical Cytometry Society.