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Difficulty: MediumOrthopedic Surgery

Match each patient's clinical and radiographic presentation with the most likely orthopedic diagnosis.

  • A 15-year-old boy with chronic thigh pain that is worse at night and dramatically improves with ibuprofen. Imaging shows a 1-cm radiolucent nidus with surrounding reactive sclerosis in the femoral cortex.Osteoid osteoma
  • A 16-year-old girl with progressive knee swelling. Imaging of the distal femur reveals a destructive medullary lesion with a 'sunburst' pattern and elevation of the periosteum (Codman triangle).Osteosarcoma
  • A 12-year-old boy with a low-grade fever and localized thigh pain. Imaging of the femoral diaphysis shows a permeative, moth-eaten lesion with an 'onion skin' periosteal reaction.Ewing sarcoma
  • A 28-year-old woman with worsening knee discomfort. Imaging of the proximal tibia demonstrates an expansile, eccentric, 'soap bubble' lytic lesion located in the epiphysis.Giant cell tumor of bone
  • A 14-year-old boy with a painless, hard mass palpable near his knee. Imaging reveals a cartilage-capped bony exostosis projecting outward from the distal femoral metaphysis, pointing away from the joint line.Osteochondroma

Answer

Presentation 1 matches with Osteoid osteoma; Presentation 2 matches with Osteosarcoma; Presentation 3 matches with Ewing sarcoma; Presentation 4 matches with Giant cell tumor of bone; Presentation 5 matches with Osteochondroma.
Each primary bone tumor has a characteristic profile. Osteoid osteoma presents with NSAID-responsive pain and a sclerotic nidus. Osteosarcoma involves the metaphysis with a sunburst pattern. Ewing sarcoma involves the diaphysis with an onion-skin pattern and can cause systemic symptoms. Giant cell tumor involves the epiphysis in adults with a soap-bubble appearance. Osteochondroma is a benign stalk pointing away from the joint.

Step-by-Step Solution

1
Analyze presentation 1
Night pain relieved by NSAIDs with a small radiolucent nidus and surrounding sclerosis.
These are the pathognomonic clinical and imaging features of an osteoid osteoma.
2
Analyze presentation 2
Metaphyseal destructive lesion with 'sunburst' pattern and Codman triangle in a teenager.
These aggressive radiographic signs indicate a malignant primary bone tumor, characteristic of osteosarcoma.
3
Analyze presentation 3
Diaphyseal permeative lesion with 'onion skin' periosteal reaction in a child with systemic symptoms.
The diaphyseal location and lamellated reaction are classic for Ewing sarcoma, which can present similarly to osteomyelitis.
4
Analyze presentation 4
Epiphyseal 'soap bubble' lytic lesion in a young adult.
An epiphyseal location in a patient with closed growth plates strongly points to a giant cell tumor of bone.
5
Analyze presentation 5
Painless bony outgrowth from the metaphysis pointing away from the joint.
This benign morphology describes an osteochondroma, the most common benign bone tumor.

Key Concept

Differentiation of primary bone tumors based on patient age, tumor location (epiphysis vs. metaphysis vs. diaphysis), and characteristic radiographic patterns.
Estimated Time:1m 30s
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Orthopedic Surgery

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