BENIGN BONE FORMING TUMORS

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BENIGN BONE FORMING TUMORS

• PRESENTED BY
• G. MICHAEL WHITEHEAD, B.S., D.C., D.A.C.B.R.

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OSTEOMA
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OSTEOMA

• General Considerations
• Benign tumor of bone tissue origin
• Contains only dense compact bone
• Solitary osteoma develops in intramembranous bone
• No malignant tendencies or progression

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OSTEOMA

• Signs and Symptoms
• M/C age 15-35
• Typically asymptomatic
• May block the ostia of the paranasal sinuses
• Complications include
• Mucoceles
• Proptosis
• Reversible blindness

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OSTEOMA

• Skeletal Locations
• M/C sites
• Inner and outer tables of the skull
• Paranasal sinuses (frontal and ethmoid)
• Mandible

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OSTEOMA

• Radiographic
• Dense radiopaque and structureless appearance
• Round or oval and well-circumscribed
• May expand the sinus wall
• Long or flat bone involvement may be
  intraosseous, surface or parosteal

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GARDNER SYNDROME

• General Considerations
• Autosomal dominant
• Triad
• Intestinal polyposis
• Multiple osteomas
• Soft-tissue tumors

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BONE ISLAND
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BONE ISLAND

• General Considerations
• A.k.a. Enostoma
• Solitary, small foci of dense bone located within
  the spongiosa
• Asymptomatic considered to be a normal variant
• Usually stable, may slowly increase in size

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BONE ISLAND

• Skeletal Location
• M/C in the pelvis and upper femora
• Tubular or flat bones
• Can be seen in the spine
• Skull not involved
• Metaphysis, epiphysis, not diaphysis

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BONE ISLAND

• Radiographic
• Well-circumscribed areas of increased density
  usually less than 1 cm
• Margins characterized by a thorn-like radiations
  or Brush Border
• Bone scan usually normal may rarely demonstrate
  uptake
• DDx. Osteoblastic metastasis

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OSTEOID OSTEOMA
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OSTEOID OSTEOMA

• General Considerations
• Common benign bone lesion
• Lesion is 1cm or less in diameter and is called a
  nidus
• Nidus is initially uncalcified, later may develop
  calcification
• Nidus consists of osteoid within a highly
  vascular stroma
• Nidus is sharply demarcated from surrounding
  reactive sclerosis
• Degree of new bone formation varies with location
  of nidus

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OSTEOID OSTEOMA

• Signs and Symptoms
• M/C age 10-25 MgtF 21
• Clinical Hallmark Local pain, worse at night
  and relieved by activity and aspirin
• Pain thought to be related to prostaglandins
  which have been recovered in the tumor
• Duration of symptoms prior to presentation ranges
  from 6 months to 2 years
• Focal soft-tissue swelling, point tenderness,
  limitation of motion may occur
• Heat and erythema do not occur

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OSTEOID OSTEOMA

• Signs and Symptoms
• Osteoid osteoma may produce a painful, rigid
  scoliosis causing nerve irritation
• Radicular pain and torticollis may occur in
  cervical spine lesion
• No systemic symptoms

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OSTEOID OSTEOMA

• Skeletal Locations
• Approximately 50 femur, tibia
• Proximal femur is m/c.
• Vertebral arch, humerus and fibula
• Any bone may be involved
• Intracortical (m/c), intramedullary
• and subperiosteal

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OSTEOID OSTEOMA

• Radiographic
• Metaphysis or diaphysis
• Classic appearance Small radiolucent
  intracortical nidus less than 1cm in diameter,
  surrounded by perifocal sclerosis and cortical
  thickening
• May see solid periosteal response
• Nidus may be calcified
• Nidus may not be centrally located within the
  area of sclerosis
• Reactive sclerosis may be prominent

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OSTEOID OSTEOMA

• Radiographic
• Intramedullary nidus ? little sclerosis
• Subperiosteal nidus ? small radiolucent bulge
  with variable cortical thickening

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OSTEOID OSTEOMA

• Advanced Imaging
• Bone scintigraphy ? uptake
• CT usually demonstrates the nidus
• MRI demonstrates abnormalities in all cases of
  osteoid osteoma
• Osteoid osteoma demonstrates a vascular blush on
  angiography

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OSTEOID OSTEOMA

• Differential Diagnosis
• Brodies abscess
• Osteoblastoma
• Stress fracture
• Early osteosarcoma
• Treatment and Prognosis
• En bloc resection, good prognosis
• Spinal lesions often irradiated

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OSTEOBLASTOMA
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OSTEOBLASTOMA

• General Considerations
• Aka Benign osteblastoma, giant osteoid osteoma.
• Rare benign bone tumor
• Similar to osteoid osteoma histiologically
• Osteoblasts and giant cells in a vascular
  connective tissue stroma

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OSTEOBLASTOMA

• Signs and Symptoms
• Peak age 10 to 20 MgtF 21
• Pain, less severe than osteoid osteoma, not
  necessarily nocturnal
• Palpable mass and tenderness may develop
• Painful scoliosis is a common complaint
• Osteoblastoma and osteoid osteoma are the m/c
  causes of scoliosis provoked by pain
• Spinal involvement ? stenosis ? neuro deficits

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OSTEOBLASTOMA

• Skeletal Locations
• Posterior arch m/c
• Tubular bones of the hands, feet
• Femur, tibia, calvarium

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OSTEOBLASTOMA

• Radiographic Spine
• Expansile, clearly defined egg-shell thin
  cortical rim
• Some spinal lesions are sclerotic the majority
  are purely lytic
• Some demonstrate matrix calcification

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OSTEOBLASTOMA

• Radiographic Long bones
• Metaphyseal or diaphyseal
• Expansile, well-circumscribed lesion
• Purely lytic or some matrix calcification
• May be surrounded by a thick periosteal reaction
  or a thin, fine margin
• Cortical breakthrough with soft tissue component
  can occur with aggressive

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OSTEOBLASTOMA

• Differential Diagnosis
• Cartilaginous tumors
• Giant-cell
• Osteoid osteoma