Physicians use imaging techniques, biopsy and staging information to evaluate a possible sarcoma. It is critical to have the correct diagnosis of these cancers to avoid complications.

The most useful imaging techniques include computed tomography scans (CT) and magnetic resonance imaging (MRI). CT scans are good for intra-abdominal and retroperitoneal areas whereas MRI is preferred for sarcomas on the limbs and planning surgery.

Biopsy may be excisional (only to remove small lesions), core needle or incisional. However, any biopsy technique must consider future surgical planning.

Staging the tumor is based on the grade and size of the tumor and whether or not it has spread. Here is the American Joint Committee on Cancer staging systemt for soft tissue sarcomas:

Stage Grouping (the meaning of the G, T, N and M terms are below)
IA: (low grade, small, superficial or deep) G1-2, T1a-1b, N0, M0
IB: (low grade, large, superficial) G1-2, T2a, N0, M0)
IIA: (low grade, large, deep) G1-2, T2b, N0, M0
IIB: (high grade, small, superficial or deep) G3-4, T1a-b, N0, M0
llC: (high grade, large, superficial)
III: (high grade, large, deep) G3-4, T2b, N0, M0
IV: any metastsis any G or T, at least N1 or M1 or both