Evaluation of a Soft Tissue Mass in the Extremity or Trunk

Abstract

Soft tissue sarcoma (STS) represents a diverse group of malignant tumors derived from mesenchymal elements. Evaluation of a soft tissue mass of the trunk or extremity starts with a detailed history and physical examination, which will help guide further diagnostic evaluation. Imaging should then be obtained for an STS, with MRI being the preferred modality for the trunk or extremities. Imaging can assist with diagnosis and delineate the extent of the primary lesion, including the relationship to contiguous structures, for treatment planning and assessing resectability. Pathology diagnosis is most commonly performed via examination of a specimen obtained through image-guided percutaneous core-needle biopsy. This requires multidisciplinary planning between Surgery and Radiology to place the needle within the anticipated definitive surgical incision to allow for en bloc resection of the needle tract. Once the diagnosis of an STS is made, appropriate staging studies should be performed based on the history and physical examination and tumor histology, grade, and size. Clinical and pathology data are used to stage STS patients using the American Joint Committee on Cancer staging system, which incorporates the STS site, size and grade of the primary tumor, and absence or presence of nodal and distant metastatic disease. This review contains 6 figures, 6 tables and 50 references Key words: core-needle biopsy, extremity, histology, imaging, risk factors, soft tissue mass, soft tissue sarcoma, staging evaluation, trunk, tumor grade