Sacrococcygeal chordoma, a rare cause of coccygodynia

Background

Coccygodynia is defined as pain in and around the coccyx; it is a symptom, not a diagnosis. Its cause remains obscure, apart from the cases caused by local injury; rare causes include chordoma, giant cell tumour, intradural Schwannoma, perineural cyst, and intra-osseous lipoma [1–3].

Chordomas are rare, low-grade, slow-growing but locally aggressive primary bone tumors [4]. The most common location is the sacrococcygeal region (40–50%) and the base of the skull (35–40%), followed by the vertebral bodies (15–20%) [5,6]. Their incidence rate is 0.5 per million [7]. Sacrococcygeal chordomas are insidious tumors that are difficult to diagnose; many patients are treated for an assortment of unrelated diagnoses before the correct diagnosis is made [7].

Case Report

TREATMENT:

The sacrococcygeal sarcoma was excised en bloc with the gluteal musculature, coccyx, and the fifth sacral vertebra. The whole capsule of the tumor was kept intact and at least 2 cm healthy surgical margins were achieved macroscopically. The histopathological report confirmed free surgical margins. The patient recovered uneventfully and was discharged on the 10^th postoperative day. He is scheduled for follow-up visits every 4 months and is doing well 28 months after the intervention.

Although chordoma is resistant to the effects of conventional radiotherapy [6,8], our institution combined the use of post-operative high LET (linear energy transfer) radiation with surgery to attempt to increase disease-free intervals.

Discussion

Surgical resection with wide margins at the initial operation is considered the treatment of choice for sacral chordoma because it improves local control and disease-free survival [9–12].

Local recurrence rates of 43% to 85% and metastases rates of 5% to 40% at 1 to 10 years have been reported for sacral chordomas [10–13]. When gluteal invasion is present, the risk of recurrence is reportedly higher and wider margins are important [14]. To obtain wide margins, a combined anteroposterior approach is usually required for proximal tumors, whereas wide resections of distal sacrum chordomas can be performed through a single posterior approach [5,10,15].

Intraoperative contamination is another major issue in sarcoma surgery [16–18]. One study reported a local recurrence of 28% after en bloc resection of chordoma compared with a 64% local recurrence rate when the tumor spilled intraoperatively [17]. Another study suggested intraoperative contamination of muscle and/or sacroiliac joint increased the probability of local recurrence [16].

Considering the above situation, we conclude that effective management of sacrococcygeal chordoma requires early diagnosis, accurate preoperative staging, definitive and adequate surgical resection with proven tumor-free cut margins, and close follow-up.

Conclusions

The most common underlying cause of coccygodynia and mass formation in the natal cleft is pilonidal disease. The 3 characteristic findings that confirm the diagnosis are: 1) abscess or sinus, 2) drainage of fluid (usually purulent), and 3) midline skin pits. In case one or more of them are absent, we should think about the rare causes of the coccygodynia such as chordoma, giant cell tumour, intradural Schwannoma, perineural cyst, and intra-osseous lipoma [19].