Patterns of bone destruction: •GEOGRAPHIC Well-defined smooth / irregular margin Short zone of transition Lytic Poorly demarcated lesion imperceptibly •PERMEATIVE merging with uninvolved bone Long zone of transition Areas of destruction with ragged borders. •MOTHEATEN Less well defined / demarcated lesional margin Longer zone of transition Sclerotic
Margin between tumor and native bone is visible on the plain radiograph. Slowly progressive process is “walled-off” by native bone, producing distinct margins. Rapidly progressive process destroys bone, producing indistinct margins.
Margin types 1A, 1B, 1C, 2, and 3 ◦ least aggressive 1A, to most aggressive 3 Aggressive lesions destroy bone. Aggressiveness increases likelihood of malignancy. ◦ BUT, not all aggressive processes are malignant. ◦ AND, not all malignant diseases are aggressive.
A well circumscribed lesion with a narrow zone of transitionincreasing aggressiveness
“Matrix” is the internal tissue of the tumor Most tumor matrix is soft tissue in nature. ◦ Radiolucent (lytic) on x-ray Cartilage matrix ◦ calcified rings, arcs, dots (stippled) ◦ enchondroma, chondroblastoma, chondrosarcoma Ossific matrix ◦ osteosarcoma
Exostosis: well defined bony projection growing away from physis Cartilage maybe calcified if lesions are large / malignant change
Nidus: a tiny radiolucent area If in diaphysis surrounded by dense bone and thickened cortex Metaphysis less cortical thickening Double density sign on bone scan – increased uptake in nidus and decreased uptake in reactive sclerotic zone (also seen in Brodie’s abcess) Lytic nidus surrounded by sclerotic bone in CT Centre of nidus may be calcified
Well demarcated osteolytic lesion sometimes containing flecks of calcification Less reactive bone than osteoid osteoma Bone scan - intense activity
Cystic radiolucency on the diaphysial side of the growth plate Cortex may be thinned and bone expanded with well defined thin sclerotic margin May have pseudo-loculated appearance secondary to irregular cortical thinning and thin septal ridges Falling fragment sign typical and the lesion is never wider than epiphysial plate Bone scan cold or minimal activity unless fractured
Gross honey comb lesion Often eccentrically placed Does not extend to the joint (unlike GCT) Warm to hot on bone scan
Usually well defined geographic lytic lesion in the epiphysis/metaphysis extending up to the joint surface without marginal sclerosis Junction with normal bone often poorly defined Cortex thinned and sometimes ballooned Bone scan warm to hot
Fibrous cortical defect Margin well defined, sometimes scalloped and often sclerosed
Ground glass appearance typical Shepherds crook deformity of proximal femur Variable appearance with expansion of cortex
Scalloped erosions on endosteal surface May have flecks of calcification
Rounded or oval rare area Usually eccentrically placed May cross the growth plate Sharp outline and sclerotic rim Scalloped margin and thin cortex
Well defined area of rarefaction eccentrically placed in the epiphysis or across the growth plate No reaction in surrounding bone 50% show central calcification, 50% show linear periosteal reaction Bone scan increased uptake at margins
Large osteolytic lesion in the midline May contain flecks of calcification Marked bone destruction
Diffuse osteopenia with multiple osteolytic lesions dispersed throughout skeleton.
Characteristic honey comb appearance in diaphysis Cortical thinning with expansion
Vertical striations without bone expansion and coarse trabecular appearance (corduroy appearance)
Mottled lytic defect usually no sclerotic rim May destroy cortex Usually endosteal or periosteal reaction Lesions in flat bones and ribs appear punched out May appear loculated due to sparing of large trabeculae Spinal lesions- collapse (vertebra plana), which may heal
Mottled or moth eaten lesion diffusely involving bone Lytic destruction common, often the cortex is perforated Onion skin appearance- layers of periosteal new bone are said to be characteristic May form Codman’s triangle
Variable with combination of bone destruction and bone formation Sun ray spicules/ sun burst appearance and Codman’s triangle may be evident Cortical breach common Adjacent soft tissue mass Joint space rarely involved ◦ 25% Lytic ◦ 35% Sclerotic ◦ 40% Mixed Telangiectatic type- purely lytic
Variable appearance with 60 - 70% have calcification and 50% have sub periosteal new bone May be a large cystic lesion with cortical destruction and central calcification, endosteal scalloping and cortical expansion; annular, punctate or comma shaped calcification
Bone often mottled or moth eaten with extension into soft tissue Osteolytic lesion may be surrounded by reactive bone Destructive appearance radiologically Usually little periosteal reaction
Osteolytic commonest - cortical destruction with little or no periosteal reaction; Lungs, Kidney, Adrenal, Thyroid, Uterus Osteoblastic deposits – Prostate, Bladder, Testis, Breast and Bowel secondaries. Also carcinoid lung tumors, lymphoma Mixed- Breast, Lung, Ovary, Cervix Lymphoma deposits may resemble prostatic deposits, i.e. sclerotic secondaries Lytic, expansile, with soft tissue mass- RCC, thyroid X-Ray- at least 50% loss of bone to produce lysis on X-ray, Loss of single pedicle produces a “winking owl sign”. CT scan, MRI
Osteolytic bone metastases:breast carcinoma shows multiple osteolytic bone lesions.
Early - vague mottled lucent areas Diffuse destructive lytic lesion with little periosteal reaction Usually combination of patchy sclerosis and mottled destruction Hogkins disease - typical appearance of ivory vertebrae
May be generalised decrease in bone density Multiple punched out defects Little bony reaction around lesions Solitary lesion = plasmacytoma; multilocular expanding lytic lesion in a red marrow area Frequently cold on bone scan