Diagnostic Approach for Muscle Sarcoma

Initial Evaluation

The European Society for Medical Oncology recommends that any unexplained deep mass of soft tissues, superficial lesion >5 cm, or any soft tissue mass in pediatric patients should be referred to a sarcoma reference center 1, 2
The American College of Radiology suggests that MRI is the preferred imaging modality for extremity and trunk wall sarcomas, providing the most accurate information for diagnosis and surgical planning 1, 2, 3
The National Comprehensive Cancer Network recommends that CT scan is used for retroperitoneal tumors or as an alternative when MRI is not feasible 1, 2
The European Society for Medical Oncology recommends that plain radiographs should be obtained first to rule out bone tumors, detect bone erosion, and identify calcifications 2, 4

The American College of Radiology recommends that MRI with contrast enhancement is essential for proper assessment of soft tissue masses 2, 3
The National Comprehensive Cancer Network suggests that CT angiogram may be useful in patients for whom MRI is not feasible 5
The European Society for Medical Oncology recommends that for staging purposes, a chest CT scan is mandatory to exclude pulmonary metastases 2, 6
The American College of Radiology recommends that abdominal/pelvic CT should be considered for specific histologic subtypes with high metastatic potential (myxoid liposarcoma, epithelioid sarcoma, angiosarcoma, leiomyosarcoma) 1, 2

The European Society for Medical Oncology recommends that multiple core needle biopsies using needles >16G are the standard approach for diagnosis 1, 2, 4
The American College of Radiology suggests that core biopsies should be performed under imaging guidance to avoid areas of necrosis 1, 3
The National Comprehensive Cancer Network recommends that the biopsy should be planned so that the biopsy tract and scar can be safely removed during definitive surgery 2, 3, 4

The European Society for Medical Oncology recommends that histological diagnosis should be made according to the latest WHO classification 2, 3, 4
The American College of Pathology suggests that the malignancy grade should be provided using the FNCLCC system, which distinguishes three grades based on differentiation, necrosis, and mitotic rate 2, 4
The College of American Pathologists recommends that tumor samples should be fixed in formalin (avoid Bouin fixation as it prevents molecular analysis) 2, 4

The European Society for Medical Oncology recommends that molecular pathology (FISH, RT-PCR) should complement morphology and immunohistochemistry when the clinical-pathological presentation is unusual, the specific histological diagnosis is doubtful, or it may have prognostic/predictive relevance 1, 2, 4, 6

The American Joint Committee on Cancer recommends that tumor size should be categorized as small (≤5 cm) or large (>5 cm) 8
The European Society for Medical Oncology suggests that tumor depth in relation to the muscular fascia (superficial vs. deep) should be recorded 2, 4
The National Comprehensive Cancer Network recommends that histological grade is a critical prognostic factor 2, 4, 8