Tumour like processes

Question 1

Paget’s Disease

Answer 1

Pathology is characterised by osteolysis followed by extensive poor-quality repair

• 5 Stages
  
  • Pre-radiographic
  • Lytic or hot phase
  • Mixed or combined
  • Sclerotic phase
  • Malignant phase (rearly ocurs under 40yrs)

Radiographic Features

• Bone Density Changes
• Coarsened Trabeculae
• Cortical Thickening
• Bone Expansion
• Long Lesion, Subarticular Extension
• Pseudo fractures (Looser’s Lines)
• Bowing Deformities (shepards crook)
• Pathological Fracture
• Expansion of vertebrae
• Thickening of endplates “picture frame” vertebrae
• Coarsened trabeculae
• Vertical striations of on vertebrae with thickening of the endplates

When the cortex of the bone can no longer contain the tumour (growing at a rapid rate) then it is a sign the disease has become malignant

Protrusio acetabuli can be similar to other diseases such as RA but with features such as loss of kohler’s line can help differentiate

Question 2

Fibrous Dysplasia

Answer 2

Non-cancerous group of disorders where normal bone is replaced with fibrous tissue. Lesions are often large and prone to expansion which leads to bone weakening.

• 3 forms
  
  • Monostotic (70%) 14yrs M=F
  • Polyostotic (27%) 11yrs M=F
  • Polyostotic with endocrine abnormalities (3%) 8yrs
    
    • McCune-Albright syndrome
    • Females

Clinical Features

• Clinical features dependent on location and size
• Monostotic
  
  • More likely to be asymptomatic
  • Upper femur: limb and intermittent pain
  • Persistent pain in long bone: pathological fracture
• Polyostotic
  
  • More likely to be symptomatic than monostotic
  • More pronounced deformity/deformity bowing bones
  • Café au lait spots (irregular margins and size)

Radiographic Features

Monostotic

• Proximal femur, ribs
• Diametaphyseal
• Geographic lucent smoky (ground glass) lesion
• Thick sclerotic margin (rind)
• Occasionally septated (soap bubbles)
• Expansion
• Cortical thinning and scalloping
• Elongated lesion
• Pathological fracture Fibrous Dysplasia
• Monostotic
• Proximal femur, ribs
• Diametaphyseal
• Geographic lucent smoky (ground glass) lesion
• Thick sclerotic margin (rind)
• Occasionally septated (soap bubbles)
• Expansion
• Cortical thinning and scalloping
• Elongated lesion
• Pathological fracture

Polyostotic

• Multiple lesions, may be unilateral
• Pseudofractures
• Deformities
• Spine rarely involved

McCune Albright Syndrome

• Bone lesions often unilateral in distribution
• Large area of café au lait spots on trunk
• Precocious sexual development
• Irregular menstruation at 5 or 6 yrs followed by development of secondary sexual characteristics

Cherubism

• Familial fibrous dysplasia of jaws
• 18mths-2yrs, regresses in puberty
• Multilocular cystic lesions in mandible/maxilla

Question 3

Neurofibromatosis

Answer 3

Non-cancerous (usually) group of disorders involving nerve sheath growths in the peripheral and/or central nervous system

Clinical + Radiographic Features

• Café au lait spots (in 50%)
  
  • Smooth margins, 6 or more >1.5cm
• Fibroma molluscum
  
  • Skin tabs: multiple, soft, elevated
• Neurofibromas
  
  • Mainly spinal and peripheral nerves

Bone changes

• Spine
  
  • Scoliosis: short, angular, kyphosis
  • Vertebral scalloping:
    
    • Posterocentral: dural ectasia
    • Eccentric, unilateral: localised dumbell neurofibroma in IVF
• Skull
  • Orbital defects, Lambdoidal defect, Macrocranium
• Ribs
  
  • Scalloped, irregular
• Long bones
  
  • Focal gigantism
  • Bilateral symmetrical non-ossifying fibromas