PD-1/PD-L1 Checkpoint in Breast Implant-Associated Anaplastic Large Cell Lymphoma: A Case Report

Abstract

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a rare form of malignancy that arises around mammary implants in patients undergoing prosthetic surgery. It has been included as a provisional entity in the revised WHO classification of lymphoid malignancy. The PD-1/PD-L1 axis is one of the major mechanisms of immune escaping exerted by several cancer types in which up-regulation of PD-L1 is observed. We report the presence of PD-1/PD-L1 checkpoint in a case of BI-ALCL of a 67 year old woman, whom previously had undergone mastectomy and reconstruction for breast carcinoma. Primary breast lymphomas are rare and account for approximately 0.04 to 0.5% of all breast cancers, with an estimated incidence of 1 case per 500.000 to 3 million women with implants [1]. The majority of these non-Hodgkin's lymphomas that affect the breast derive from B-lymphocytes and less than 10% are of T-cell origin [2]. In recent years, a distinct subset of T-cell lymphomas, so-called breast implant-associated anaplastic large cell lymphoma (BI-ALCL) has been described in women with breast implants.