Staging of Bone Tumors

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Enneking staging for benign musculoskeletal tumors based on radiographic characteristics of the tumor host margin

Stage Description
Latent Well-demarcated borders
Active Indistinct borders
Aggressive Indistinct borders



Enneking staging for malignant musculoskeletal tumors based on:

  • surgical grade
  • local extent
  • presence or absence of metastasis
Stage Grade Site Metastasis
IA Low (G1) Intracompartmental (T1) No metastasis (M0)
IB Low (G1) Extracompartmental (T2) No metastasis (M0)
IIA High (G2) Intracompartmental (T1) No metastasis (M0)
IIB High (G2) Extracompartmental (T2) No metastasis (M0)
III Any (G) Any (T) Regional or distant metastasis (M1)

The system aids in assessing prognosis & planning management

NB: Applies to lesions of connective tissue, not primary lesions of round cell origin (eg leukaemia's, lymphomas, myeloma or Ewings)


Grade (assessment of biological aggressiveness)

Features of aggressive tumours:

  • Cellular atypia
  • Frequent mitoses
  • Extensive necrosis
  • Significant vascularity
  • Small amounts of immature matrix
G0    Histologically benign (well differentiated and low cell to matrix ratio)
G1    Low grade malignant (few mitoses, moderate differentiation and local spread only); Have low risk of metasases
G2    High grade malignancy (frequent mitoses, poorly differentiated); High risk of metasases



Description of the TGNM system of the American Joint Committee for Cancer ( AJCC ) for staging of soft tissue sarcomas

TGNM component Description
Primary tumor (T)
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor ≤ 5 cm
  T1a Superficial tumor
  T1b Deep tumor
T2 Tumor ≥ 5 cm
  T1a Superficial tumor
  T1b Deep tumor
Regional lymph nodes (N)
NX Regional lymph nodes cannot be assessed
N0 No regional node metastasis
N1 Regional lymph node metastasis
Distant metastasis (M)
MX Distant metastasis cannot be assessed
M0 No distant metastasis
M1 Distant metastasis
Histologic grade (G)
GX Grade cannot be assessed
G1 Well differentiated
G2 Moderately differentiated
G3 Poorly differentiated
G4 Dedifferentiated or anaplastic


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