Successful surgical resection of a rare case of a giant sacral chordoma: a multidisciplinary feat

Abstract

We, here, report the case of a 72-year-old man who presented with a giant sacral chordoma without aggressive clinical and neurological course and confirmed with a CT guided biopsy. The patient underwent multidisciplinary, two-stage successful complete en bloc sacrectomy along with total gross tumour resection, followed by lumboiliac fusion and instrumentation in the second stage without any neurological deficit nor bladder or bowel-related complications.

Background

Chordoma is a rare type of cancerous tumour, locally invasive, slow-growing, occurring in approximately one per million individuals,¹ accounting for 1%–4% of all bone neoplasm² and are thought to originate from remnants of the embryonic notochordal cells. The development of chordoma in men is more than in women (ratio 2:1)³ and about half of all chordomas arise in the sacrococcygeal area, one-third in the clivus area and the rest in the remaining vertebrae of the spine. Chordomas mainly occur in adults between ages 40 and 70 and around 5% of chordomas occur in children with a more aggressive clinical course. Metastasis occurs only in 10% of cases to lungs, liver, lymph nodes, skin and muscles.⁴

Treatment is in the form of surgical excision, radiation therapy or a combination of both modalities. The current study encountered a rare case of giant sacral chordoma in an adult that was successfully resected with no postoperative complications.

Case presentation

A 72-year-old man, with history of controlled hypertension and benign prostatic hyperplasia, was admitted to our neurosurgery division with a slow growing, very large hard mass of the sacral region which became easily palpable over the previous 2 months and a recent increase in size after a core biopsy was done in an outside institution.

Physical examination revealed a large hard sacral mass with some extension into the gluteal area with smooth surface adherent to the sacrum and not to the skin. Neurological examination showed no motor or sensory lower extremities deficits, normal rectal tone and no perianal anaesthesia.

Investigations

Laboratory investigations taken were unremarkable. Radiography showed an osteolytic sacral lesion (figure 1A, B). Lumbosacral spine MRI revealed a giant (18×14 cm) diffuse infiltrative bone tumour involving the entire sacrum and coccyx causing marked expansion of the sacrum with cortical destruction. It has a low signal on T1, heterogeneous intermediate signal intensity on T2 and high signal intensity on short-TI Inversion Recovery (STIR). Findings are mostly compatible with chordoma (figure 2).

Figure 1.

Sagittal (A) and Axial (B) CT scan showing the osteolytic and destructive nature of the tumour.

Figure 2.

A lobulated tumour appears with low intensity on T1 sagittal (A) and with high intensity on T2 sagittal (B) MRI. A coronal view (C) shows a markedly heterogeneous signal in the anterior component of the tumour in keeping with a necrotic component.

CT-guided percutaneous core-cut biopsy was performed in an outside institution prior to the patient referral to our department, revealed multiple variably sized lobules separated by thick fibrous bands and occasional bone trabeculae. The tumour cells are epithelioid large polygonal with moderately atypical nuclei and abundant eosinophilic to clear cytoplasm with multiple areas of partial necrosis. The tumour cells stained positively for CKAE 1/3 and EMA but S100 stain was negative. Positron emission tomography (PET) scan showed no evidence of other lesions. The overall findings were consistent with chordoma (figure 3A, B).

Figure 3.

(A) Histopathology slide showing low power view showing variably sized lobules separated by thick fibrous bands. (B) High power view showing large epithelioid polygonal cells with moderately atypical nuclei and abundant eosinophilic cytoplasm. Some cells have intracytoplasmic clear vacuoles (physaliphorous cells).

Differential diagnosis

Although the initial differential diagnoses were wide and included secondary malignant tumours of the sacrum, which are more common than primary malignant tumours, PET scan was done to rule out other primary sources of the mass.

Although imaging findings of primary sacral tumours often overlap, sacral chordoma was suggested on the top of our differential diagnoses depending on certain features: it was a midline mass that was lobulated, containing areas of necrosis and involving the lower sacral vertebrae and the coccyx; while chondrosarcoma tends to be eccentrically located and involves the upper sacral levels.

Foci of bone formation, which are usually seen as foci of signal void, were absent in MRI sequences making osteosarcoma less likely.

Giant cell tumour of bone (osteoclastoma) is more common in females of younger age group and extension across the sacroiliac joint is frequent.

Ewing sarcoma was at the bottom of the differential diagnosis; since it usually occurs in teenage groups and the extraosseous part is typically larger than the intraosseous one.

In the end, the diagnosis of chordoma was suggested by the clinical history and the radiological features and was confirmed by the morphology of tumour on microscopy and the immunohistochemistry staining.

Treatment

A multidisciplinary meeting was called for by the neurosurgery team and included the general surgery, vascular surgery, plastic surgery, oncology, neurology and anaesthesia teams. Preoperative electromyography was performed in addition to full neurological examination that revealed no neurological sensory or motor deficit and normal rectal bone with no perianal anaesthesia.

Two stage-surgery was performed. First stage for tumour resection and second stage for lumbopelvic internal fixation.

Day 1, under general anaesthesia, the patient was placed in a lithotomy position for anterior pelvic release of the tumour from the surrounding structures, including iliac vessels, bladder, uterus, colon, rectum and sacral plexus. Using a midline abdominal incision, a transperitoneal approach was used. After placement of Bookwalter retractor, smooth successful release of the tumour from the surrounding structures and the rectum was achieved. The abdomen was closed in the usual fashion and the patient was then positioned in a prone Jackknife position (figure 4). A large gauze was placed in the rectum for easier identification. A 20 cm midline incision was carried out at the site of the sacral area reaching to the anal region (figure 5). Subcutaneous plane was identified and followed along all muscular attachments using spray cautery and LigaSure to reach the lateral, superior and inferior borders of the tumour (online supplemental video 1). Full tumour disconnection was achieved from surrounding structures (figure 6). At the lumbosacral junction the thecal sac was ligated and cut below S2, followed by sacral amputation at S2. Bilateral L5, S1 and S2 nerve roots were identified and preserved using nerve root stimulation. Both of the S2 nerves were at the margin of the tumour and they were skeletonised carefully. Laterally, the tumour and the infiltrated sacrum were surgically separated at the sacroiliac joints. Inferiorly, the tumour was carefully dissected off its attachment to the anal sphincter and the rectum, to reach the anterior pelvic cavity through the wide posterior approach.

Figure 4.

Patient in prone Jackknife position.

Figure 5.

Midline incision and subcutaneous identification of tumour.

Figure 6.

Identification of tumour borders and disconnection from surrounding structures.

Once all the tumour attachments were separated and complete sacral amputation at S2 level was achieved, the tumour was en bloc delivered posteriorly and the internal and external anal sphincters were surgically repaired (figure 7). The wound was closed using muscle flap by the plastic surgery team (figure 8).

Figure 7.

Posterior en bloc delivery of tumour.

Figure 8.

En bloc resected tumour.

On the second day, a double Hockey stick incision was used and we made sure that it was not communicating with the first stage midline incision to avoid entering the pelvic cavity. A lumbopelvic internal fixation (L2–L5 iliac bone) was performed (figure 9) (figure 10A–C) and the wound was closed using bilateral gluteal advancements flaps by the plastic surgery team. The total duration of the two-stage surgery was 16 hours, 8 hours for each stage. No major intraoperative complications were encountered. Vital signs were stable and within normal limits during the surgery. Blood loss was estimated to be 500 cc in the first stage and the patient was supported with two units of packed red blood cells (PRBC) in preparation for the second stage surgery. No postoperative motor or sensory deficits were noted. Histopathology report confirmed the preoperative diagnosis of sacral chordoma.

Figure 9.

Lumbopelvic internal fixation on day 2. Double hockey stick incision without communication with the midline incision of day 1.

Figure 10.

Intraoperative fluoroscopy showing the instrumentation in place.

Outcome and follow-up

Postoperative day 1, the patient was ambulated with the help of the physiotherapy team and returned to his independent baseline gait few days after the surgery (online supplemental video 2). Foley catheter was left in for 2 weeks after the surgery after which the patient regained the ability to control voiding. The patient was able to pass stools on postoperative day 5. The anterior and posterior wounds healed with a good outcome (figure 11A, B).

Figure 11.

The well-healed wound anteriorly (A) and posteriorly (B).

Discussion

Chordomas are rare primary malignant tumours arising from embryonic notochordal remnants.⁵ They account for about 17.5% of axial primary malignant bone tumours.^{1 5} Although chordomas can arise at any location in the spine,^{6 7} most arise at the sacrum. Although they are considered low-grade tumours, chordomas are locally aggressive, invasive, highly recurrent and have a poor prognosis.⁸

Skull tumours are usually small in size but difficult to remove because of their proximity to the brain. Sacrococcygeal tumours usually present as large masses and are difficult to resect fully.⁹

Although chordomas are highly invasive, they have little metastatic potential, with a reported rate of 5%–10%. The most common metastatic sites include the lungs and the axial skeleton, but unusual locations like orbital and skin metastases have also been reported.^10–12

Staging can be achieved by a detailed history and physical examination, and diagnostic tests (CT, MRI and bone scans). On early CT scan, chordomas present as areas of bone destruction at the centres of vertebral bodies along with ventral or lateral paraspinal calcified soft-tissue mass. At later stages, the pedicles, laminae and spinous processes are usually involved by the tumour, however, disc spaces are usually spared. Currently, gadolinium-enhanced MRI is the gold-standard imaging modality for the diagnosis and surgical planning. The bony expansion and calcification of chordomas are usually hypointense to isointense on T1-weighted MRI, hyperintense on T2-weighted MRI and enhance with gadolinium.¹³

The diagnosis is usually confirmed through an open or true-cut needle biopsy. In sacral chordomas, a transrectal biopsy is contraindicated as it may cause seeding of the bowel. Histologically, these tumours are characterised by the physaliphorous (soap bubble) cells.¹⁴

Several reports have described a correlation between the volume of the tumour and the postsurgical outcome. Sacral chordomas larger than 10 cm or with a volume of >200 cm³ or more have an unfavourable prognosis.^15–18

Due to the high complication and morbidity rates, a multidisciplinary team is usually required in the management of patients with these tumours.^{19 20} En bloc resection with adequate surgical margin is usually needed to reduce local recurrence.^21–25 These tumours are usually chemoresistantand radioresistant.²¹ Proton beam therapy after en bloc resection of sacral chordomas has added a better local control and overall survival benefit. Besides, it has a low toxicity profile.²⁶

Despite the recent advancement in surgical techniques, complications of sacrectomy are still common.¹⁰ The most commonly reported complications in the literature are massive haemorrhage, wound complications (wound dehiscence, surgical site infection), neurological deficits (neurogenic bowel and bladder, sciatic nerve or lumbosacral plexus injury) and instrumentation-related complications in iliopelvic fixation.19 25 27–29 Many authors have considered ileostomy and suprapubic bladder catheter as an unavoidable post-surgical complication in large chordomas.³⁰

The complication rate is directly related to the tumour size. There are only few reported cases in the literature reaching a very large size, Phang et al³¹ reported a case of sacral chordoma measuring 43×38×27 cm, while Yang et al³² reported a case measuring 17×17×15 cm on MRI. Although they achieved en bloc resection of these tumours, the patients had neurogenic bowel and bladder postsacrectomy requiring enema and long-term urinary catheter. In addition, the postoperative course was complicated by wound breakdown and surgical site infection requiring wound debridement.

The importance of our reported case is that we were able to perform an en bloc resection of a giant chordoma (18×14 cm) and sacrectomy, followed by a second stage iliopelvic fixation with good functional outcome and without any neurological deficit and absence of any procedure-related complications mentioned in the literature.

Learning points.

• Sacral chordomas are rare tumours, and they can reach large sizes and invade the surrounding structures.

• The management of sacral chordoma is challenging and patients with sacral chordoma are best managed in a multidisciplinary approach.

• En bloc resection with adequate surgical margin and sacrectomy offered the best chance of reducing local recurrence and can be achieved in multistage surgeries.

• Postoperative follow-up protocol is needed.

• Poor prognosis is usually related to the tumour size and age of onset.