METASTATIC CALCIFICATION

Calcinosis is the term applied to a condition marked by a widespread abnormal deposition of calcium salts in various tissues of the body. In some conditions, such as dystrophic calcification, one must assume a previous retrogressive change in the tissues with subsequent deposition of calcium salts. In other conditions, however, the lime salts are deposited in previously healthy tissues. In the latter instance there are, owing to some still unexplained factor, mobilization of the calcium from the normal depots in bones and redistribution to various tissues and organs in the body. Oversaturation of the blood with calcium salts occurs in some cases. This condition was first recognized by Virchow,¹ who called it "metastatic calcification." Since then many reports have appeared in the literature.² Such calcification is not limited to any one condition but has been reported in association with a variety of diseases, such as scleroderma, dermatomyositis, nephritis,