production and osteoblastic activity.
– widened osteoid seams are seen in osteomalacia (Looser’s lines); they are areas of uncalcified osteoid that surround mineralized bone. Seen in osteomalacia and rickets.
– most common area of mets from a rhabdomyosarcoma – lymph nodes
– UBC’s often recur after curettage and bone grafting; they also often do not heal after fracture. Most common site is the proximal humerus
– gout can be seen after leukemia, multiple myeloma, polycythemia and lesch Nyan syndrome. It is not seen with hemophilia.
– osteogenesis imperfecta – the collagen crosslinking is abnormal. “In patients with OI, several recent reports have shown a considerable increase in concentrations of types III and V collagen and a marked variation in cross-linking”.
(Lovell and Winter)
– look for intra-osseous ganglia in carpal bones (scaphoid in particular)
– osteoblastoma – most common location is posterior elements of the spine.
– rhabdomyosarcoma – mets to lymph nodes (along with leiomyosarcoma, synovial sarcoma, epitheliod sarcoma)
– multiple myeloma, sarcoidosis, thyrotoxicosis, and metastatic breast Ca all cause hypercalcemia; medullary carcinoma of the thyroid does not (it produces calcitonin, which decreases calcium)
– amyloidosis is often seen with multiple myeloma (10%)
– dystrophic calcification is calcification of DEGENERATIVE TISSUE
– ivory vertebrae – lymphoma!
– GCT’s are one of the few benign lesions to have a predeliction for the ANTERIOR spinous elements.
– fracture through the distal radius with a big GCT – probably best to do a wide excision and primary arthrodesis
– anterolateral bowing of the tibia that shows up at birth – congenital pseudarthrosis of the tibia
– for patients with soft tissue sarcomas with postop XRT – watch for radiation induced osteonecrosis of adjacent bones. They do not get bony metastasis!
– synovial cell sarcoma: classically a biphasic pattern with 2 distinct cell populations – spindle cells and epitheloid cells. The spindle cells are predominant, and are plump and form an interlacing pattern. The epithelioid cells form glandlike structures.