[Structure and ultrastructure of osteoblasts and of the osteoid tissue in Paget's disease of bone (author's transl)].

Light and electron microscope studies of 64 biopsies from patients with Paget's bone disease reveal the structure of osteoblasts and osteoid tissue. The osteoblasts observed do not differ morphologically from those described in other bone diseases and the woven bone shows no specificity. These cells are possibly hyperactive and our observations show that such hyperactivity may be consequent to the increased and disorganized resorption of lamellar bone tissue by osteoclasts which are known to be abnormal. Osteoblasts do not appear to play any direct role in the pathogenesis of Paget's bone disease.