Soft Tissue Biopsy

Background and indications

Image-guided percutaneous soft tissue biopsy (muscles, subcutaneous tissue, fascia) enables histological diagnosis of soft tissue masses and tumors (sarcomas, atypical lipomas, metastases, inflammatory or infectious lesions). Ultrasound or CT guidance ensures precise and representative sampling.

The biopsy tract must be planned in consultation with the orthopedic or oncological surgeon, as in case of sarcoma, the tract will need to be excised en bloc during definitive surgery.

Pre-procedure assessment

Assessment includes MRI of the affected area (reference examination for soft tissue tumor characterization), coagulation panel, and multidisciplinary discussion (sarcoma tumor board) if malignancy is suspected. The biopsy tract is jointly planned with the surgical team.

Procedure

Under local anesthesia, a biopsy needle (14-18G, automatic or semi-automatic) is inserted under ultrasound or CT guidance. The tract is direct, avoiding unaffected compartments and neurovascular bundles. 3 to 5 cores are obtained targeting solid, non-necrotic areas of the lesion. The procedure takes 15 to 30 minutes.

Results and scientific evidence

Image-guided percutaneous soft tissue tumor biopsy offers a diagnostic yield of 83-97% and concordance with final surgical diagnosis of 90-95%. Core needle biopsy has largely replaced open surgical biopsy as the primary diagnostic method.

Risks and complications

Local hematoma (5-10%, generally inconsequential), puncture site pain (10-20%), infection (< 0.5%). Tumor seeding along the tract is minimal (< 0.1%) with a well-planned, excisable tract.

Recovery

Relative rest is recommended for 24-48 hours. A compressive dressing is applied. Histological results are available within 5-10 days. In case of suspected sarcoma, diagnosis may require specialized pathology expertise.

Practical information

The procedure is performed as an outpatient or short inpatient stay depending on the case. It is performed by an interventional radiologist, in coordination with the surgical and oncological team.