OBJECTIVETo observe and analyze the pathohistological characteristics of capsules which formed around the mammary prosthesis with different contents. And to provide the selective basis for ideal and safe prosthesis in clinical practice.

METHODS20 specimen of the capsules were taken from 20 cases who receive the operation of prothesis removal for different reasons. HE, Masson and Mallory staining were used to analyse the tissue structure and characteristics under the light microscope.

RESULTSThe common structure including the collagen fibers accumulation, inflammatory cells infiltration and the capillary hyperplasia were found in all specimen. A layer of squamous epithelium-like cell was detected in some specimen. The specific characteristics were also found in different capsules formed around different prosthesis. In the capsules around vegetable oil prosthesis, there was excessive collagen fiber accumulation, and the capsules were much thicker. In the PVP (polyvinylpyrolidone) prosthesis capsules, there was severe inflammatory cell infiltration, and the number of eosinophilic granulocyte increased obviously. In the silicone gel and saline prosthesis capsule, the collagen fibers were well-arranged and the inflammatory cells were much less. Synovial metaplasia was detected in two cases.

CONCLUSION1. The capsules form around the prosthesis in all cases after mammary augmentation. 2. There will be synovial metaplasis in some cases, for vegetable oil prosthesis, the collagen over-accumulated which lead the capsules become thicker and harder. So it is not a kind of ideal mammary prothesis. 4. The severe infiltration of the inflammatory cells especially the large quantity of eosinophilic granulocyte indicate the possibility of the delayed hypersensitive reaction mediated by eosinophilic granulocyte. Cautious attitude should be taken during application.