Biopsy (the taking of a piece of the tumour for microscopic analysis) is the key diagnostic test and where the possibility of sarcoma is real, the surgeon will be careful to ensure that the tract of the biopsy needle or knife is through tissue that will be resected at any definitive operation, so as not to contaminate new tissues that will not be resected.
Once the microscopic/histological diagnosis is made, then there are several staging scans that are performed to establish the extent of the disease. For assessing the extent of the primary tumour, MR imaging is best as it demonstrates the contrast of tumour from background tissues best and allows the surgeon to plan his operation optimally. For assessing the possibility of metastatic disease, then CT scanning of the lungs is optimal.
