Bone & joints

Other osteogenic tumors

Osteoid osteoma


Resident / Fellow Advisory Board: Erna Forgó, M.D.
Deputy Editor-in-Chief: Borislav A. Alexiev, M.D.
Elham Nasri, M.D.
John D. Reith, M.D.

Topic Completed: 11 November 2021

Minor changes: 2 December 2021

Copyright: 2003-2021, PathologyOutlines.com, Inc.

PubMed Search: Osteoid osteoma [TI] pathology [TIAB]

Elham Nasri, M.D.
John D. Reith, M.D.
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Cite this page: Nasri E, Reith JD. Osteoid osteoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/boneosteoidosteoma.html. Accessed December 3rd, 2021.
Definition / general
  • Benign, bone forming tumor
  • Usually small size (< 2 cm) and limited growth
Essential features
  • Imaging: well demarcated, small central nidus, usually surrounded by zone of sclerosis
  • Histology: bone forming tumor composed of woven bone with prominent osteoblastic rimming and a vascularized stroma
  • Molecular: FOSB gene locus rearrangement (not necessary for diagnosis)
ICD coding
  • ICD-10: D16.20 - benign neoplasm of long bones of unspecified lower limb
Epidemiology
  • 10 - 12% of all benign bone tumors; 2 - 3% of all primary bone tumors
  • M:F = 2:1
  • Rare familial occurrence reported (Skeletal Radiol 2003;32:416)
  • More common in children and adolescents
Sites
  • Broad skeletal distribution
    • 50% occur in the long bones of the lower extremities
      • Femoral neck is the single most frequent anatomic site
      • Usually near the end of the diaphysis of long bones
    • Less common in the long bones of upper extremities
      • Bones of elbow are the most common site in upper extremity
    • Small bones of hands and feet and posterior elements of vertebral body
    • Uncommon sites: flat bones, craniofacial bones
  • Preferential involvement of cortex (75%)
    • Subperiosteal and intramedullary lesions are less common
  • Reference: J Bone Oncol 2015;4:37
Etiology
  • Unknown
Clinical features
  • Nocturnal pain, relieved by aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) (J Am Acad Orthop Surg 2011;19:678)
  • Swelling and effusion of nearest joint in intracapsular osteoid osteomas
  • Painful scoliosis in osteoid osteomas of spine (Neurosurg Focus 2003;15:E5)
  • Osteoid osteomas in the small bones of the hands and feet may clinically mimic osteomyelitis
Diagnosis
  • Requires correlation of clinical, radiographic and histologic findings
Radiology description
  • Xray:
    • Intracortical lesions have a nidus with a variable degree of mineralization and surrounding reactive osteosclerosis
    • Intramedullary lesions may be more difficult to visualize on conventional radiography and often lack the surrounding sclerotic bone
  • CT scan:
    • Well defined oval to round nidus with low attenuation
    • Reactive cortical sclerosis
  • MRI:
    • Generally of limited value in the detection of a nidus, with the exception of intramedullary lesions
    • Characteristics of nidus tissue (depending on the degree of mineralization):
      • Low to intermediate signal intensity on T1 weighted images
      • Variable signal intensity on T2 weighted images
      • Target-like appearance of partially mineralized nidus
    • Bone marrow edema and joint effusion
    • Intracapsular lesions may be associated with marked synovitis, leading to an erroneous diagnosis of an inflammatory arthropathy
  • Isotope scan:
    • Zone of increased uptake corresponding to nidus and perilesional sclerosis
  • Reference: Radiographics 2010;30:737
Radiology images

Contributed by Elham Nasri, M.D. and John D. Reith, M.D.
Tibia

Tibia

Elbow Elbow

Elbow

Finger Finger

Finger


Distal femur Distal femur

Distal femur

Distal femur

Distal femur

Wrist Wrist

Wrist

Prognostic factors
Case reports
Treatment
  • NSAIDs
  • CT guided percutaneous radiofrequency ablation (Radiology 2003;229:171)
    • Symptomatic patients, nonresponsive to NSAIDs
    • Outpatient
    • Minimally invasive
  • Curettage and resection (Orthopade 2017;46:510)
    • Vertebral column
    • Small bone of hands and feet
    • Close relationship to peripheral nerves
    • Recurrent lesions
  • Reference: Acta Biomed 2018;89:175
Gross description
  • Oval red nidus is easily distinguishable from surrounding tissue
    • Soft and friable to sclerotic nidus
    • Surrounded by densely sclerotic reactive bone
Gross images

Contributed by John D. Reith, M.D.
Nidus tissue with surrounding bone

Nidus tissue with surrounding bone

Frozen section description
  • Not usually performed
Microscopic (histologic) description
  • Nidus:
    • Haphazard trabeculae of woven bone with prominent osteoblastic rimming
      • Different thickness and mineralization level
      • Disordered (Pagetic) cement lines in some cases
      • Sheet-like osteoid deposition in some cases
      • Densely sclerotic woven bone in some cases
  • Surrounding bone:
    • Thickened trabeculae of bone with adjacent loose fibrovascular stroma
  • Reference: Am J Surg Pathol 2019;43:1661
Microscopic (histologic) images

Contributed by Elham Nasri, M.D. and John D. Reith, M.D.
Well defined borders

Well defined borders

Osteoblastic rimming

Osteoblastic rimming

Sheet-like osteoid deposition

Sheet-like osteoid deposition

Sclerotic nidus

Sclerotic nidus

Peripheral transition to sclerotic bone

Peripheral transition to sclerotic bone

Bone trabeculae with variable mineralization

Bone trabeculae with variable mineralization

Positive stains
Molecular / cytogenetics description
Sample pathology report
  • Mass, distal metaphysis, left tibia, biopsy:
    • Osteoid osteoma
Differential diagnosis
Board review style question #1
Osteoid osteoma most likely shows rearrangement of which of the following genes?

  1. DDIT3
  2. EWSR1
  3. FOS / FOSB
  4. USP6
Board review style answer #1
C. FOS / FOSB

Comment Here

Reference: Osteoid osteoma
Board review style question #2

Provided H&E picture belongs to a well defined intracortical lesion of distal tibia of a 17 year old boy. Symptoms include nocturnal pain that is relieved by ibuprofen. What is the correct diagnosis?

  1. Aneurysmal bone cyst
  2. Giant cell tumor of bone
  3. Osteoid osteoma
  4. Osteomyelitis
Board review style answer #2
C. Osteoid osteoma

Comment Here

Reference: Osteoid osteoma
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