Bone biopsy in an involved area of bone with paget's disease MOST likely show which of the following?
The characteristic finding on histologic examination of a biopsy from a patient with Paget disease of bone is a mosaic pattern of lamellar bone. This pattern, which resembles a jigsaw puzzle in appearance, reflects the tight apposition of irregular units of bone that adhere to one another with prominent cement lines. These findings are characteristic of fully developed Paget disease, and are the ones most likely to be illustrated on an examination. However, you should be aware that early Paget disease typically shows lytic rather than proliferative bone lesions, and it is thought that the primary defect involves the osteoclasts, which are typically abnormally large with more than the usual number of nuclei. This is followed by overly vigorous osteoblastic activity, which eventually produces the characteristic mosaic bone. Benign spindle cells growing in a storiform pattern are characteristic of fibrous coical defect and nonossifying fibroma. A cailage nodule within a bony medullary cavity is characteristic of enchondroma. Spirochetes visible with silver stain are a feature of skeletal syphilis. Ref: Chandrasoma P., Taylor C.R. (1998). Chapter 67. Diseases of Bones. In P. Chandrasoma, C.R. Taylor (Eds), Concise Pathology, 3e.
Benign spindle cells growing in a storiform pattern
Cailaginous nodule within a bony medullary cavity
Mosaic pattern of lamellar bone
Spirochetes visible with silver stain