[Suture granuloma with calcium pyrophosphate deposits]

In the report two foreign body granulomas, one observed in the fibrous periarticular tissue and the other one in tendo achilles with depositions of crystals inside the granulomas are described. Polarisation microscopy exhibited birefringent crystals which stained black with the van Kossa reaction. The scanning electron microscopic appearance was that of calcium-pyrophosphate-dihydrate when compared with crystals of menisceal tissue in "chondrocalcinosis". The structure of the crystals was different from those that can be observed in calcifying tendinitis or in calcified scars. By X-ray microanalysis nearly identical peaks for calcium and phosphorus were measured, indicating the atomic composition of calcium-pyrophosphate-dihydrate. For the crystalline deposits were restricted to an acellular tissue between the foreign body material it is concluded that necroses in the fibrous periarticular tissues or tendons may be prone for deposition of calcium-pyrophosphate.