Ultrastructural study of calcinosis universalis with dermatomyositis

Calcinosis universalis associated with dermatomyositis occurred in a 58-year-old woman. Tissues removed from the sublingual region in the patient were studied by ordinary microscopy, electron microscopy, and an electron-microanalytic method. The calcified materials were distributed on collagen fibers and seemed to have a relationship with foci of fibrinoid degeneration. Moreover, globular and/or membranous structures, considered to originate from the degenerate cells of the stroma, were observed in these calcified zones. Some of them contained electron-dense materials. Therefore, the globular and/or membranous structures were thought to be concerned with initial calcification in this case. Furthermore, irregular bone tissue was formed adjacent to the calcified masses. In addition, the calcified materials were identified by X-ray diffraction examination and electron microscopy as hydroxyapatite.