乳房インプラント関連エプスタイン・バー・ウイルス陽性びまん性大細胞型B細胞リンパ腫（BIA-EBV陽性DLBCL）の片側性症例報告と文献レビュー

Breast implant associated anaplastic large cell lymphoma with a single T cell clone is an uncommon complication especially related to implants with a textured surface. Moreover, there are few reports of breast implant-associated Epstein-Barr virus-positive diffuse large B-cell lymphoma (BIA-EBV-positive DLBCL), which typically presents unilaterally. Here, we present a case of bilateral BIA-EBV-positive DLBCL.

A 79-year-old woman who underwent breast implantation 40 years prior presented with unilateral capsular contracture. However, after bilateral total capsulectomy, the final diagnosis was bilateral BIA-EBV-positive DLBCL. The tumor cells found in the intracapsular effusion and fibrin tissue covering the luminal side of the capsule were positive for LCA, CD20, CD79a, CD30, BCL2, MUM1, and PD-L1 according to immunohistochemical staining, and EBER in situ hybridization revealed a high Ki67 index (60%-70%). The patient was disease free during the postoperative follow-up period of 43 months.

Latent EBV infection plays an important pathogenic role, contributing to the indolent nature and restrictive proliferation of such cases, which are currently classified as fibrin-associated DLBCL. We aim to highlight the reasons for the delayed diagnosis of the disease, the possible pathologic findings on the contralateral side, and the potential need for prophylactic bilateral total capsulectomy. We also reviewed reported cases of BIA-EBV-positive DLBCL to gain a better understanding of its incidence, risk factors, diagnostic tools, pathogenesis, and prognosis.