[The mineral phase of Malherbe's calcifying tumor].

The mineral phase of a calcified tumour of Malherbe (pilomatrixoma) was studied using microradiography, chemical analysis and X-ray diffraction. It was compared with the mineral phase of a piece of human mandibular bone from a matched subject with respect to age and sex. The main part of the mineral phase of the pilomatrixoma belonged to the biological apatite system; an additional whitlockite phase was found. In the homogeneous areas of the tumour, the radioopacity was similar to that of bone.