Bone Tumors

Bone tumors have several features that are characteristic and can be used to narrow a differential diagnosis for a suspicious lesion. This table is by no means comprehensive but it is meant to be a quick reference for various benign and malignant osseous lesions. The following features are relevant: patient age, lesion borders, location within bone, bones, involved, bone matrix changes, periosteal reaction, matrix mineralization, and soft tissue component.

The patients can be divided into two groups based on age: younger than 30 vs older than 30. The lesion borders can be described as a narrow zone of transition (the border is easy to define) vs a broad zone of transition. Periosteal reactions can be described as thin, thick, lamellated, hair-on-end, sunburst, or Codman's triangle. Matrix mineralization is either chondroid (rings and arcs) or osteoid (cloud-like). A soft tissue component is either present or absent.

Diagnoses	Age	Bones	Borders	Physis?	Cortex?	Periosteal Reaction	Matrix Mineralization	Soft Tissue Mass
Fibrous Dysplasia	under 30	Face, ribs, femur	Narrow	Metadiaphysis	No	No	No	No
Eosinophilic granuloma	under 30	Face, humerus, ribs, femur	Narrow	Metadiaphysis	Possible	Variable	No	Yes, if fx
Osteoid osteoma	under 30	Long bones	Narrow	Metaphysis	Yes	No	No	No
Nonossifying fibroma	under 30	Distal femur, distal tibia	Narrow	Metaphysis	Yes	No	No	No
Simple Bone Cyst	under 30	Proximal humerus, proximal femur	Narrow	Metaphysis	No	No	No	No
Osteochondroma	under 30	Distal femur, proximal tibia	Narrow	Metaphysis	Yes	No	No	No
Ewing Sarcoma	under 30	Long bones, ribs	Broad	Diaphysis	Yes	Lamellated	No	Yes
Osteosarcoma	under 30	Long bones	Broad	Metaphysis	Yes	Sunburst, hair-on-end, Codman's	Osteoid	Yes
Enchondroma	under 30	Small bones	Narrow	Metadiaphysis	Yes	No	No	No
Aneursymal Bone Cyst	under 30	Posterior vertebrae, flat bones, long bones	Narrow	Epiphysis	Yes	Yes	No	No
Chondromyxoid fibroma	under 30	Long bones	Narrow	Metaphysis	Yes	No	Chondroid	No
Chondroblastoma	under 30	Distal femur, proximal humerus	Narrow	Epiphysis	Yes	No	Chondroid	No
Osteomyelitis	any age	Any	Broad	Any	Yes	Thick	No	No
Myeloma	over 30	Any	Narrow	Metadiaphysis	Yes	No	No	No
Geode	over 30	Periarticular	Narrow	Epiphysis	Yes	No	No	No
Hyperparathyroidism	over 30	Any	Narrow	Metadiaphysis	Thinned	No	No	No
Giant Cell Tumor	over 20	Knee, distal radius, sacrum	Narrow	Epiphysis	No	No	No	Eggshell ossification