Capsular synovial metaplasia mimicking silicone leak of a breast prosthesis: a case report

Abstract

Introduction: Synovial metaplasia around a prosthesis and in particular around silicone breast implants has been noted by various investigators, but has unknown clinical significance. We report on a patient where a large amount of synovial fluid mimicked rupture of an implant. We believe this to be an unusual clinical presentation of this phenomenon. Review of the English language literature failed to identify a comparable case.

An unusual case of a ruptured Poly Implant Prothèse breast implant associated with xanthoma

“…[ 1 ] Similarly to other studies we observed some fluid effusion during implant removal as a result of synovial metaplasia associating with implant rupture. [ 1 , 4 , 21 , 22 ]…”

FNA of peri‐implant seroma of the breast

“…9 In addition to forming the capsule-implant interface, synovial metaplasia has also been associated with the development of peri-implant fluid collections, which may occasionally mimic a silicone leak on radiological studies. 10 The present case highlights the diagnostic challenge of evaluating a late breast implant-associated seroma. Although the eventual aetiology was probably benign and related to exuberant synovial metaplasia, both radiological and on-site pathological assessments focused on malignant entities, and the radiological appearance of this lesion raised significant concern for BI-ALCL.…”

“…This theory is supported by experimental studies, which demonstrate the development of synovial metaplasia following injection of air into the subcutaneous tissue of mice . In addition to forming the capsule‐implant interface, synovial metaplasia has also been associated with the development of peri‐implant fluid collections, which may occasionally mimic a silicone leak on radiological studies …”

Clinical Implications and Management of Non–BIA-ALCL Breast Implant Capsular Pathology

“…Synovial metaplasia often presents as a seroma or unilateral breast swelling and is usually found incidentally on pathologic examination. 21,22 Case reports have described synovial metaplasia as the cause of an intracapsular fluid collection that was thought in one instance to be BIA-ALCL and in another to be a ruptured saline implant. 21,23 Synovial metaplasia is a benign condition occurring in 40% to 77% of breast implant capsules independent of implant texture and fill.…”

“…21,22 Case reports have described synovial metaplasia as the cause of an intracapsular fluid collection that was thought in one instance to be BIA-ALCL and in another to be a ruptured saline implant. 21,23 Synovial metaplasia is a benign condition occurring in 40% to 77% of breast implant capsules independent of implant texture and fill. 24,25 In response to microtrauma from the implant moving in the capsule pocket, the capsule attempts to repair itself by developing a synovial lining analogous to an articular joint.…”