17 terms

#5: Paget Disease, FIbrous Dysplasia, non-ossifying fibroma & hypertrophic osteoarthropathy

Dr Khin
Paget disease (osteitis deformans)
associated with irregular thickening and softening of bones
begins after 40, peak after 60; mainly whites
Etiology of Paget Disease
slow virus (paramyxovirus) infection suggested
nuclear inclusions found in osteoclasts of pts;
active live viruses have not been isolated from bone
polyostotic in 85%, monostotic in 15%
Stages of Paget disease
initial osteolytic stage (bone resorption by osteoclasts)
mixed osteolytic-osteoblastic stage (shows woven bone w/mosaic pattern)
burnt-out, quiescent osteosclerotic stage
Morphology of Paget disease
any bone can be affected (commonly spine, pelivs, femur, skull, tibia, humerus)
Paget effects on spine
thickening/softening results in kyphosis, shortening of trunk and pressure on nerves in vertebral foramina
Paget effects on skull
progressive increase in the size of skull due to bone thickening;
base may be involved with pressure in nerves
Paget effects on femur
increase thickness with coxa vera and anterior bowing
What is pathognomonic of Paget disease?
mosaic pattern
Clinical signs of Paget disease
initially: bone pain, fractures, deformites; deafness if skull
vertebral compression -> height distortion
coarsening of facial bones -> leontiasis ossea (lion face)
serum alkaline phosphatase elevated
X-ray shows bone lysis/reformation
osteosarcoma ~1%
Moste useful lab test in diagnosing Page disease
serum alkaline phosphatase
Fibrous dysplasia
benign condition characterized by replacement of bone by disorganized fibrous and osseous elements
may involve single or multiple bones or may be associated with skin pigmentation and endocrine disturbances
Monostotic fibrous dysplasia
most common (70%)
age = 2nd and 3rd decade
any bone but mainly proximal femur, tibia, ribs or facial bones
may be asymptomatic or lead to pathologic fracture
Polyostotic fibrous dysplasia
25% of cases; more than one bone involved
usually in childhood - pathologic fracture, limb deformities, limb length discrepancies
more common in females
Albright syndrome
most common endocrine abnormality
precocious puberty in females
acromegaly, Cushing, hyperthyroidism
pigmented macules (cafe au lait spots)
Histologic features of Mono, poly and albright
benign fibroblastic tissue in a whorled pattern with haphazardly arranged trabeculae of woven bone
serum alkaline phosphate elevated but calcium and phosphate levels normal
non-ossifying fibroma (fibrous cortical defect)
non-neoplastic developmental lesion mainly in kids
femur, tibia, fibula
Hypertrophic osteoarthropathy
disorder characterized by periosteal new bone formation, arthritis and clubbing of digits
usually in pts with bronchial carcinoma (sometimes pleural tumors, pulmonary metastases, mediastinal Hodgkins disease, chronic lung infections and chronic liver disease