Repeated Fluid Accumulation around a Breast Implant Related to Synovial Metaplasia of the Capsule.

We must take special care when treating postoperative fluid accumulation around breast implants (BIs) to exclude any serious complications, including BI-associated anaplastic large cell lymphoma. However, most late-onset fluid accumulation is caused by other conditions, such as traumatic hematoma and residual postoperative seroma. Surgeons must choose whether to conservatively observe or remove such BIs, while also determining whether to perform partial capsulectomy or total capsulectomy to solve the problem of fluid accumulation. We treated a 72-year-old woman who noticed swelling in her right breast 4 years after undergoing bilateral BI reconstruction. Before she was referred to our hospital, the fluid had been drained by needle aspiration five times, but the swelling returned to a similar size within a month. No malignant findings were observed by needle-aspirated cytology or flow cytometry. The patient requested the simultaneous removal of the left BI. Therefore, we performed both BI removal with total capsulectomy on the right side and partial capsulectomy of the superficial layer on the left side. A pathological examination of the capsule on the right side indicated a chronic expanding hematoma and synovial metaplasia characterized by papillary projections rich in CD68-positive cells, thus indicating reactive synovial cells. In contrast, the left superficial capsule was much thinner and showed less synovial metaplasia. Our findings indicate the advantages of total capsulectomy to solve the problem of repeated serous fluid accumulation around BIs, according to histological changes in the capsule.