Points to notice during the diagnosis of soft tissue tumors according to the “Clinical Practice Guideline on the Diagnosis and Treatment of Soft Tissue Tumors”

To adequately treat soft tissue tumors, an accurate initial diagnosis is essential. In this article, we describe the notable points during initial diagnoses as outlined by the “Clinical Practice Guideline on the Diagnosis and Treatment of Soft Tissue Tumors”. Clinical findings including pain and tumor size, growth speed, and depth, may be important in the diagnosis. In general, malignant soft tissue tumors tend to be larger than 5 cm in size, to occur in deep layers, and grow quickly. However, there are many exceptions. Magnetic resonance images can show characteristics of soft tissue tumors, but most of these are non-specific. The most reliable diagnostic procedure is histological examination. Therefore, a biopsy is mandatory. A core needle biopsy can be performed under local anesthesia at an outpatient clinic without the need for imaging guidance. In cases with deep-seated tumors, an image-guided biopsy is recommended. Incisional biopsies are also widely used procedures. In an incisional biopsy, the skin incision should be parallel to the long axis of the extremities. A meticulous hemostasis must be carried out to prevent post-biopsy hemorrhaging. If adequate hemostasis cannot be achieved, a drain is placed within the incision or at the closest possible site along the incision. Indications for an excisional biopsy are limited to superficial soft tissue tumors, less than 3 cm in size, located at a suitable distance from the nearest vital structure. Furthermore, an excisional biopsy should only be carried out after imaging studies are complete.