Wide surgical tumor excision with adequate margins appears to be the procedure of choice in chondrosarcoma treatment, since this is the most effective way of reducing tumor recurrence rate -. Although local recurrence after inadequate surgical removal does not seem to significantly influence the overall survival, it must be kept in mind that each local recurrence bears the risk of the tumor evolving towards a higher-grade chondrosarcoma (up to 21.4%) . Such transformation could consequently lead to an increased risk of metastases and subsequently result in a reduced overall survival rate [8, 9]. A number of authors believe that the tumor grade is the only significant prognostic factor for survival and metastases [4, 5].
A recent paper reported a recurrence rate of 100% in grade I pelvic chondrosarcoma following intralesional resection. Hence, although such a procedure may be considered a treatment option in some grade I chondrosarcomas of the long bones of the extremities, intralesional tumor resection should be avoided in the treatment of pelvic tumors . The fact that in our case there was a tumor recurrence twice following partial removal supports the above findings.
Most chondrosarcomas of the pelvis are considerably larger than their appendicular counterparts, averaging 11 cm in size at the time of diagnosis. This could be partly attributed to the poor compartmentalization of the pelvis and the fact that most such tumors, as in our case, give raise to symptoms only after they have reached a relatively large size .
After inadequate initial excision there is increased likelihood of local recurrence because recurrent lesions have the propensity to implant in the pelvic soft tissues and do not remain as one isolated large lesion [9, 10]. This seems to apply in our case where two recurrences of the tumor occurred within two decades.
The fact that in our case the first recurrence of the tumor took place more than a decade and the second almost 20 years post initial tumor resection indicates another aspect of the natural history of such tumors. Indeed, it is pointed out in the literature, that the index recurrence was seen as late as 87 months after the initial resection, while second recurrence occurred up to 12 years after index recurrent surgery. Thus, patients with a known recurrence should be followed for at least 15 to 20 years, a time considerably longer then that required for most other types of tumors. Unfortunately, even 10 years of monitored relapse-free status does not ensure cure of the disease . Even in the cases of recurrent chondrosarcomas, the current literature suggests that every effort to achieve adequate resection margins should be made [9, 10].
The choice of surgical procedure constitutes a factor of paramount importance. The surgeon has to maintain a subtle balance between ensuring adequate resection margins and the risk of endangering adjacent vital structures as well as the structural stability of the pelvis.
According to Enneking and Dunham  the pelvis is divided into 4 zones. The ilium is assigned number I, the periacetabular area number II, zone III corresponds to the pubis and ischium and zone IV to the sacrum. The extent of the excision needed according to the pelvic tumor location defines the reconstruction procedure required in order to reestablish stability and functionality of the pelvic ring. It is well documented in the literature that after zone III resection without impairment of the posterior structural elements a reconstruction of the anterior pelvic arch is not required, since pelvic stability is not affected . Therefore, in our case we focused on achieving adequate resection margins through the bone but also through the soft tissues.
In order to reduce the possibility of a postoperative visceral herniation due to the removal of the anterior pelvic osseous substrate, we supported the anterior abdominal wall with a special synthetic mesh that was fixed upon the pelvic osseous stumps. This porous, monofilament polypropylene mesh acts as a "scaffold" enhancing growth of the patient's own tissue, which eventually incorporates the mesh into the surrounding area. This technique is often used in abdominal surgery for treatment of sizeable hernias.