INTRODUCTION

Soft tissue sarcomas account for about 1% of all adult cancers, but this proportion increases to nearly 10% in children under 15 years old. These tumors constitute a heterogeneous group of neoplasms with still relatively unknown etiology. The overall survival of patients with soft tissue and connective tissue sarcomas is around 50% at five years after treatment initiation, with tumors located in the extremities having a more favorable prognosis than those in other locations¹.

As far as surgical treatment of sarcomas is concerned, it has dramatically changed over the last three decades. Forty years ago (1970-1980), it involved radical surgery with resection of the entire muscular compartment or amputation of the limb. Nowadays, limb-sparing surgery can be performed in over 80% of cases. In oncological surgery, the objectives of surgical resection are complete removal of the tumor with wide margins and minimal functional compromise, avoiding postoperative sequelae or morphological deformities.

A proper understanding of anatomical elements allows for approaching a topographical region or performing a compartmental or extracompartmental surgery, considering anatomical relationships mainly with the vasculonervous axis, bony structures, and other adjacent tissues.

The specific objective of this study is to identify landmarks and anatomical elements of the external compartment of the upper third of the leg, both in anatomical dissection and in surgery, with an emphasis on the course of the external sciatic or common peroneal nerve, as well as its bony and muscular relationships, and the identification of its branches.

CASE PRESENTATION

A 68-year-old patient presented to a surgical service with a complaint of pain on the outer side of the upper third of the right leg, persisting for 6 months.

Physical examination revealed a slightly immobile soft tissue tumor. Further extension studies, including ultrasound and CT scans, were conducted, along with a percutaneous biopsy confirming the diagnosis of a soft tissue tumor on the outer side of the upper third of the right leg. A compartmental surgery was performed, preserving the common fibular nerve and using the head of the fibula as a landmark (Figures 1 and 2). The anatomopathological diagnosis reported a soft tissue tumor with clear margins. Figure 3 shows the cadaveric dissection of the common fibular nerve.

Figure 1.  Soft tissue tumor on the outer side of the upper third of the right leg. 

Figure 2.  Common fibular nerve (external popliteal nerve), identifying the head of the right fibula. 

Figure 3.  Cadaveric dissection of the upper third of the right leg. Common fibular nerve (external popliteal nerve) and its branches in relation to the peroneal muscles. 

DISCUSSION

For a low-grade tumor in a patient, surgery and proper dissection of the region are crucial, with a conservative approach to the lower limb and the identification of important vasculonervous elements in the region, considering aesthetics, gait, and patient prognosis^1-2. In the specialized literature, great importance is given to compartmental and wide-margin surgery³. The treatment of a soft tissue tumor is dependent on the lesion size^4-5 and anatomical compartment of the areas^7-8, and the patient's follow-up through regular physical examinations and imaging studies must also be considered.