1. Anatomy of the leg compartments 2. Radiological considerations: which modality? 3. Do's and don'ts of lesion biospy 3. Pictorial review of percutaneous biopsy approches.

The leg comprises of four osseofascial compartments by: interosseous membrane of the leg,transverse intermuscular septum & theanterior intermuscular (crural) septum 1. Anterior: muscular tibialis anterior extensor hallucis longus extensor digitorum longus neurovascular deep peroneal nerve anterior tibial vessels 2. Lateral: muscular peroneus longus peroneus brevis neurovascular superficial peroneal nerve 3. Superficial Posterior: muscular gastrocnemius plantaris soleus neurovascular sural nerve 4. Deep Posterior: muscular tibialis posterior flexor hallucis longus flexor digitorum longus popliteus neurovascular tibial nerve posterior tibial vessels Benign and aggressive lesions can be found...

Anatomy Modalities: Ultrasound has been shown tobe an effective triage tool (Lakkaraju A et al)and in conjunction with MRI (Gielen JL et al, Mutlu H et al), most soft tissue tumours can becharacterised with a high degree of sensitivity and specificity as either benign, indeterminateor malignant. Management including biopsy must be decided through a sarcoma MDT (Shah et al). Close collaboration witha multidisciplinary team that consists of a surgicaloncologist, oncologist, and musculoskeletal (MSK)pathologist is vital. Surgical management depends on the lesion location, number or compartments...

We have highlightedthe importance of a detailed understanding of compartmental anatomy when approaching apatient with a lower extremity musculoskeletal mass. We havedescribed the interventional/surgical management of such lesions.

Davies NM, Livesley PJ, Cannon SR. Recurrence of anosteosarcoma in a needle biopsy track. J Bone Joint Surg Br1993;75:977–978 Gielen JL, De Schepper AM, Vanhoenacker F, Parizel PM, Wang XL, Sciot R et al.Accuracy of MRI in characterization of soft tissue tumors and tumor-like lesions. Aprospective study in 548 patients. Eur Radiol. 2004 Dec;14(12):2320-30. Helms CA. ‘‘Don’t touch’’ lesions. In: Fundamentals ofSkeletal Radiology. 2nd ed. Philadelphia: WB Saunders;1995:56–77 Lakkaraju A, Sinha R, Garikipati R, Edward S, Robinson P. Ultrasound for initialevaluation and triage of clinically...

Dr Amit Shah, Department of Radiology, Royal Orthopaedic Hospital, Birmingham B21 3AP, UK Dr Rajesh Botchu, Department of Radiology, Royal Orthopaedic Hospital, Birmingham B21 3AP, UK Mr Robert U Ashford, Deprtment of orthopaedics, Leicester Royal Infirmary, Infirmary Square, LE1 5WW Dr Winston Rennie, Deprtment of Radiology, Leicester Royal Infirmary, Infirmary Square, LE1 5WW