Journal of Orthopaedic Surgery 2014;22(3):409-14
Total sacrectomy for low-grade malignant peripheral nerve sheath tumour: a case report Piya Kiatisevi,1 Chaiwat Piyaskulkaew,2 Bhasanan Sukunthanak,1 Voranuch Thanakit,3 Saraporn Bumrungchart4 Orthopaedic Oncology Unit, Institute of Orthopaedics, Lerdsin General Hospital, Bangkok, Thailand Spine Unit, Institute of Orthopaedics, Lerdsin General Hospital, Bangkok, Thailand 3 Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand 4 Department of Radiology, Lerdsin General Hospital, Bangkok, Thailand 1 2
ABSTRACT We report on a 58-year-old woman who underwent total sacrectomy and spinopelvic reconstruction for a low-grade malignant peripheral nerve sheath tumour involving the sacrum. One week later, she developed deep wound infection, and the entire spinopelvic reconstruction was removed. At the 36-month followup, the patient had no pain and was able to walk with a walking frame. There was no sign of recurrence or metastasis. Key words: nerve sheath neoplasms; reconstructive surgical procedures; sacrum
INTRODUCTION Malignant peripheral nerve sheath tumours (MPNSTs) involving the sacrum are rare.1–4 Most of MPNSTs are high grade and involve the extremities in patients aged 20 to 50 years.5,6 Nonetheless, about
20% of MPNSTs are low grade and have better disease-specific survival.6–8 We report a 58-yearold woman who underwent total sacrectomy and spinopelvic reconstruction for a low-grade MPNST involving the sacrum. CASE REPORT In July 2010, a 58-year-old woman presented with a 2-year history of progressive lower back pain radiating to the left leg and a one-year history of gradual swelling of her lower back. She reported no bowel or bladder symptoms and had no history of neurofibromatosis. On examination, a swelling of 15 cm in diameter, with a soft consistency, was noted at her lower back. Neurological examination results including perianal sensation and anal sphincter tone were normal. Radiographs showed an osteolytic lesion in the sacrum destroying the sacral body and foramina (Fig. 1). Full body bone scan showed increased uptake at L5 from degenerative change, but not at the sacral area (Fig. 1). Magnetic resonance imaging (MRI) and computed tomography
Address correspondence and reprint requests to: Dr Piya Kiatisevi, Orthopaedic Oncology Unit, Institute of Orthopaedics, Lerdsin General Hospital, Bangkok, Thailand. Email: [email protected]
410 P Kiatisevi et al.
(a)
(b)
(c)
(d)
Figure 1 (a) Radiographs showing an osteolytic lesion destroying the sacral body and foramina, (b) full body bone scan showing increased uptake at L5 from degenerative change but not at the sacral area, (c) magnetic resonance images showing a large, heterogeneous, soft-tissue mass involving the sacral body, left ilium, sacroiliac joint, and lamina, and protruding into the presacral and pelvic cavity, compressing and displacing the uterus, urinary bladder, and rectosigmoid anteriorly, and (d) computed tomography showing a large mass at the presacral area destroying almost the entire sacrum and extending to the L5-S1 disc.
Journal of Orthopaedic Surgery
(CT) showed a large heterogeneous tumour with haemorrhage extending from the sacrum to the L5-S1 level involving the left internal iliac vessels, but not the rectum or urologic structures (Fig. 1). Intravenous pyelography confirmed no involvement of the urologic structures. CT of the thorax and abdomen showed no signs of distant metastasis. Open biopsy performed elsewhere prior to referral to our hospital revealed low-grade MPNST. Total sacrectomy with marginal or wide margins and spinopelvic reconstruction was planned. The patient underwent preoperative embolisation to reduce 80% of the blood supply to the tumour area 2 days prior to the operation. The L5-S1 disc and both sacroiliac joints were to be resected with the sacrum. The patient was placed in the supine position, and a midline longitudinal skin incision was made. Retroperitoneally, the ureters were identified and protected, and the bilateral iliac arteries and veins were ligated and transected. The L5-S1 interverterbral disc was exposed and detached from the L5 endplate. The rectum was mobilised by blunt finger dissection in the presacral area. Abdominal swabs were temporarily packed just anterior to the iliac bones bilaterally to protect important vessels and nerves from posterior ilium osteotomies. The wound was closed and the patient was turned to the prone position. A midline longitudinal incision was made, and the gluteal and paravertebral muscles were dissected from the sacrum and the lower lumbar spine. The sacrospinous and sacrotuberous ligaments were transected bilaterally. After an L5 laminectomy, the dural sac was transected caudal to the L5 nerve roots and double ligated with nonabsorbable sutures. The bilateral L5 and above nerve roots were kept intact. To achieve adequate margins, both ilia were osteotomised, leaving part of the right sacral ala attached to the right anterior sacroiliac joint. The L5-S1 disc was detached from the L5 endplate, and the tumour was removed en bloc. The wound was then washed, and the abdominal swabs were removed. Pedicular screws were inserted into L3, L4, and both sides of the ilia and the right L5 pedicle, and rods were placed in position. A massive (11 cm in length, 25 mm in diameter) freeze-dried humeral allograft filled with antibiotic cement was inserted horizontally between the iliac bones and fixed with 2 partially threaded cancellous screws (Fig. 2). Another small piece (4 cm in length and 1.5 cm in height) of humeral allograft was packed tightly between L5 and the horizontal allograft. Two deep suction drains were inserted. The gluteal muscles were sutured together to cover the reconstruction. The fascia and skin were closed without tension. The total operating
Vol. 22 No. 3, December 2014
Total sacrectomy for nerve sheath tumour 411
(a)
(b)
Figure 2 Spinopelvic reconstruction with structural humeral allografts and a rod–pedicular screw system. (c)
time was 8 hours. Blood loss was 8000 ml, and 17 units of erythrocyte concentrate and 11 units of freshfrozen plasma were transfused. Postoperatively, the patient had weak dorsal flexion of her left ankle and big toe, and a custom-made ankle-foot orthosis was applied. The resected mass with an opaque, whitish cut surface measured 17.0x15.5x12.5 cm and had foci of haemorrhage, cystic changes, and approximately 40% necrosis (Fig. 3). Microscopic examination showed dense spindle cells arranged in a fascicle and herring bone pattern. Oval cells with occasionally buckled nuclei, hyperchromasia, and light eosinophilic cytoplasm were noted. Scattered large atypical cells with hyperchromatic nuclei intermingled with the spindle cell. Approximately 5/10 high-power fields of mitoses were noted (Fig. 3). The surgical margin was uninvolved. Immunohistochemical staining for S-100 protein showed focal positivity in spindle cells, and 20% and 5% of tumour cell nuclei were positive for Ki-67 and p53, respectively (Fig. 3). One week later, the patient developed deep wound infection and underwent debridement and removal of the entire spinopelvic reconstruction (Fig. 4). Wound swab culture grew Staphylococcus aureus. The patient was given intravenous cefazolin for 6
(d)
Figure 3 (a) The tumour is opaque and whitish in colour, with foci of cystic change, haemorrhage, and approximately 40% necrosis, (b) spindle cells are arranged in a fascicle and herring bone pattern, with scattered large atypical cells; oval nuclei and irregular contours with occasional buckle nuclei are noted; and mitoses are 5/10 high-power fields (H&E, x200), (c) immunohistochemical staining for S-100 protein shows focal positive in the spindle cells (x200), and (d) the proliferation index estimated with antibodies against Ki-67 is 20% (x200).
Journal of Orthopaedic Surgery
412 P Kiatisevi et al.
(a)
(b)
(c)
Figure 4 Radiograph of the pelvis after removal of the allografts and spinopelvic reconstruction owing to deep wound infection.
weeks and underwent 2 additional debridements and vacuum-assisted closure. The wound eventually healed after 2 months. As there was no reconstruction of the pelvis, the patient was bed-bound for 2 months. She was able to sit without support at month 3 and able to stand and walk with a walking frame at month 4. At the 18- and 36-month follow-up, the patient had no pain and was able to walk with a walking frame for one and 4 hours, respectively. Although the bilateral L5 and above nerve roots were kept intact, the patient was unable to dorsiflex her right ankle and toes. She managed to use the ankle-foot orthosis well. She had difficulty in urinating and needed intermittent catheterisation, and her anal tone remained flaccid. Her Musculoskeletal Tumor Society score was 21 out of 30. Repeat MRI and CT of the chest showed no recurrence or pulmonary metastasis (Fig. 5). Radiographs of the pelvis showed that the spinal column had sunk down into the pelvis (Fig. 5). CT of the pelvis showed the left transverse processes of L3, L4, and L5 fused to the left ilium and the right transverse processes of L4 and 5 fused to the remaining right sacrum (Fig. 5).
Figure 5 At the 36-month follow-up, (a) magnetic resonance images showing no tumour recurrence, (b) radiographs showing the spinal column sinking to the pelvis, and (c) computed tomography showing the left transverse processes of L3, L4, and L5 fused to the left ilium, and the right transverse processes of L4 and L5 fused to the right sacrum.
DISCUSSION Surgical resection with adequate margins is the treatment of choice for MPNST.6 Although MPNST is generally resistant to chemotherapy and radiotherapy, postoperative radiotherapy is still recommended to increase both disease-free and overall survival.8,9
Vol. 22 No. 3, December 2014
Approximately 20% of MPNSTs are low grade with increased disease-specific survival,6–8 but in one study survival does not correlate with tumour grading.7 One study reported 4 cases of low-grade MPNSTs (3 in lower extremities and one in the retroperitoneum).10 Low-grade MPNST is characterised with moderate cellularity of spindle cells with irregular contours and buckle nuclei with a herring bone pattern, necrosis, mitoses, and focal S-100 protein reactivity.11 Although cellular schwannoma also shows hypercellularity of dense spindle-shaped cells arranged as sweeping fascicles and in a herring bone pattern, necrosis is not common and usually in focal areas only.12 Tumours in the sacral area tend to grow to a considerable size before detection. Sacral neurogenic tumours can be classified according to their growth pattern to determine the appropriate surgical approach.13 A combined anteroposterior approach is recommended for giant neurogenic sacral tumours expanding to the S1 spinal canal.14 The use of the anterior approach to dissect the tumour and ligate the internal iliac vessels (especially the internal iliac arteries) may reduce intra-operative blood loss and complications related to injury to the intrapelvic organs. Ligation of the internal iliac arteries is effective and safe for controlling massive haemorrhage in pelvic surgery because of the multiple sources of collateral blood flow in the pelvis.15–17 Nonetheless, buttock ischaemia secondary to necrosis of the glutei muscles, weakness, and lumbosacral plexopathies have been reported after internal iliac artery ligation for gynaecological surgery, but these complications usually occur in patients with severe aortoiliac vascular disease or risk factors such as insulin-
Total sacrectomy for nerve sheath tumour 413
dependent diabetes mellitus or prior radiotherapy treatment.15 Preoperative embolisation can also reduce intra-operative blood loss and enable complete tumour resection and improved outcome.18,19 Spinopelvic reconstruction after total sacrectomy is necessary for early rehabilitation and ambulation.4,20–24 In our patient, deep infection developed at week 1, and the entire spinopelvic reconstruction was removed. Without spinopelvic reconstruction, the patient was bed-bound for 2 months. The lumbar spine migrated inferiorly and remained between the ilia. The patient was able to walk with a walking frame at month 4. This may be because the muscles and scar tissue between the pelvis and the spine formed a biological sling and eventually stabilised the spine.24 In 9 patients who underwent total sacrectomy through the L5 (n=3) or L5-S1 level (n=6), functional outcome did not differ significantly between patients with (n=4) and without (n=5) reconstruction.24 Nonetheless, spinopelvic stabilisation is still recommended in patients with total sacrectomy and removal of most of both iliac wings.24 For patients without spinopelvic reconstruction, tolerance for sitting, standing, and walking can be improved with the use of a lumbar-sacral corset, as it decreases lumbar-sacral motion, reduces the load on the lumbosacral spine, and reduces excessive lumbar lordosis to provide a straighter and more comfortable low back.25 DISCLOSURE No conflicts of interest were declared by the authors.
REFERENCES 1. Grnja V, Allen WE 3rd, Osborn DJ, Kier EL. Sacral neurofibrosarcoma: an angiographic evaluation. Case report. J Neurosurg 1974;40:767–71. 2. Crosbie DC, Carney PG, Sage MR. Sacral neurofibrosarcoma—a case report. Australas Radiol 1986;30:54–6. 3. Lin PP, Horenstein MG, Healey JH. Sacral mass in a 56-year-old woman. Clin Orthop Relat Res 1997;344:333–7. 4. Min K, Espinosa N, Bode B, Exner GU. Total sacrectomy and reconstruction with structural allografts for neurofibrosarcoma of the sacrum. A case report. J Bone Joint Surg Am 2005;87:864–9. 5. Hruban RH, Shiu MH, Senie RT, Woodruff JM. Malignant peripheral nerve sheath tumors of the buttock and lower extremity. A study of 43 cases. Cancer 1990;66:1253–65. 6. Stucky CC, Johnson KN, Gray RJ, Pockaj BA, Ocal IT, Rose PS, et al. Malignant peripheral nerve sheath tumors (MPNST): the Mayo Clinic experience. Ann Surg Oncol 2012;19:878–85. 7. Ducatman BS, Scheithauer BW, Piepgras DG, Reiman HM, Ilstrup DM. Malignant peripheral nerve sheath tumors. A clinicopathologic study of 120 cases. Cancer 1986;57:2006–21. 8. Kar M, Deo SV, Shukla NK, Malik A, DattaGupta S, Mohanti BK, et al. Malignant peripheral nerve sheath tumors (MPNST)— clinicopathological study and treatment outcome of twenty-four cases. World J Surg Oncol 2006;4:55. 9. Ferner RE, Gutmann DH. International consensus statement on malignant peripheral nerve sheath tumors in neurofibromatosis. Cancer Res 2002;62:1573–7. 10. Yamaguchi U, Hasegawa T, Hirose T, Chuman H, Kawai A, Ito Y, et al. Low grade malignant peripheral nerve sheath tumour:
414 P Kiatisevi et al.
Journal of Orthopaedic Surgery
varied cytological and histological patterns. J Clin Pathol 2003;56:826–30. 11. Trojani M, Contesso G, Coindre JM, Rouesse J, Bui NB, de Mascarel A, et al. Soft-tissue sarcomas of adults; study of pathological prognostic variables and definition of a histopathological grading system. Int J Cancer 1984;33:37–42. 12. White W, Shiu MH, Rosenblum MK, Erlandson RA, Woodruff JM. Cellular schwannoma. A clinicopathologic study of 57 patients and 58 tumors. Cancer 1990;66:1266–75. 13. Klimo P Jr, Rao G, Schmidt RH, Schmidt MH. Nerve sheath tumors involving the sacrum. Case report and classification scheme. Neurosurg Focus 2003;15:E12. 14. Wei G, Xiaodong T, Yi Y, Ji T. Strategy of surgical treatment of sacral neurogenic tumors. Spine (Phila Pa 1976) 2009;34:2587– 92. 15. Shin RK, Stecker MM, Imbesi SG. Peripheral nerve ischaemia after internal iliac artery ligation. J Neurol Neurosurg Psychiatry 2001;70:411–2. 16. Gokaslan ZL, Romsdahl MM, Kroll SS, Walsh GL, Gillis TA, Wildrick DM, et al. Total sacrectomy and Galveston L-rod reconstruction for malignant neoplasms. Technical note. J Neurosurg 1997;87:781–7. 17. Tomita K, Tsuchiya H, Kawahara N, Hata M, Murakami H. En bloc sacrectomy. In: Watkins RG, editor. Surgical approaches to the spine. New York: Springer-Verlag; 2003:205–16. 18. Gottfried ON, Schmidt MH, Stevens EA. Embolization of sacral tumors. Neurosurg Focus 2003;15:E4. 19. Yang HL, Chen KW, Wang GL, Lu J, Ji YM, Liu JY, et al. Pre-operative transarterial embolization for treatment of primary sacral tumors. J Clin Neurosci 2010;17:1280–5. 20. Blatter G, Halter Ward EG, Ruflin G, Jeanneret B. The problem of stabilization after sacrectomy. Arch Orthop Trauma Surg 1994;114:40–2. 21. Tomita K, Tsuchiya H. Total sacrectomy and reconstruction for huge sacral tumors. Spine (Phila Pa 1976) 1990;15:1223–7. 22. Shikata J, Yamamuro T, Kotoura Y, Mikawa Y, Iida H, Maetani S. Total sacrectomy and reconstruction for primary tumors. Report of two cases. J Bone Joint Surg Am 1988;70:122–5. 23. Kawahara N, Murakami H, Yoshida A, Sakamoto J, Oda J, Tomita K. Reconstruction after total sacrectomy using a new instrumentation technique: a biomechanical comparison. Spine (Phila Pa 1976) 2003;28:1567–72. 24. Wuisman P, Lieshout O, Sugihara S, van Dijk M. Total sacrectomy and reconstruction: oncologic and functional outcome. Clin Orthop Relat Res 2000;381:192–203. 25. Guo Y, Yadav R. Improving function after total sacrectomy by using a lumbar-sacral corset. Am J Phys Med Rehabil 2002;81:72–6.
Total sacrectomy for low-grade malignant peripheral nerve sheath tumour: a case report Piya Kiatisevi,1 Chaiwat Piyaskulkaew,2 Bhasanan Sukunthanak,1 Voranuch Thanakit,3 Saraporn Bumrungchart4 Orthopaedic Oncology Unit, Institute of Orthopaedics, Lerdsin General Hospital, Bangkok, Thailand Spine Unit, Institute of Orthopaedics, Lerdsin General Hospital, Bangkok, Thailand 3 Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand 4 Department of Radiology, Lerdsin General Hospital, Bangkok, Thailand 1 2
ABSTRACT We report on a 58-year-old woman who underwent total sacrectomy and spinopelvic reconstruction for a low-grade malignant peripheral nerve sheath tumour involving the sacrum. One week later, she developed deep wound infection, and the entire spinopelvic reconstruction was removed. At the 36-month followup, the patient had no pain and was able to walk with a walking frame. There was no sign of recurrence or metastasis. Key words: nerve sheath neoplasms; reconstructive surgical procedures; sacrum
INTRODUCTION Malignant peripheral nerve sheath tumours (MPNSTs) involving the sacrum are rare.1–4 Most of MPNSTs are high grade and involve the extremities in patients aged 20 to 50 years.5,6 Nonetheless, about
20% of MPNSTs are low grade and have better disease-specific survival.6–8 We report a 58-yearold woman who underwent total sacrectomy and spinopelvic reconstruction for a low-grade MPNST involving the sacrum. CASE REPORT In July 2010, a 58-year-old woman presented with a 2-year history of progressive lower back pain radiating to the left leg and a one-year history of gradual swelling of her lower back. She reported no bowel or bladder symptoms and had no history of neurofibromatosis. On examination, a swelling of 15 cm in diameter, with a soft consistency, was noted at her lower back. Neurological examination results including perianal sensation and anal sphincter tone were normal. Radiographs showed an osteolytic lesion in the sacrum destroying the sacral body and foramina (Fig. 1). Full body bone scan showed increased uptake at L5 from degenerative change, but not at the sacral area (Fig. 1). Magnetic resonance imaging (MRI) and computed tomography
Address correspondence and reprint requests to: Dr Piya Kiatisevi, Orthopaedic Oncology Unit, Institute of Orthopaedics, Lerdsin General Hospital, Bangkok, Thailand. Email: [email protected]
410 P Kiatisevi et al.
(a)
(b)
(c)
(d)
Figure 1 (a) Radiographs showing an osteolytic lesion destroying the sacral body and foramina, (b) full body bone scan showing increased uptake at L5 from degenerative change but not at the sacral area, (c) magnetic resonance images showing a large, heterogeneous, soft-tissue mass involving the sacral body, left ilium, sacroiliac joint, and lamina, and protruding into the presacral and pelvic cavity, compressing and displacing the uterus, urinary bladder, and rectosigmoid anteriorly, and (d) computed tomography showing a large mass at the presacral area destroying almost the entire sacrum and extending to the L5-S1 disc.
Journal of Orthopaedic Surgery
(CT) showed a large heterogeneous tumour with haemorrhage extending from the sacrum to the L5-S1 level involving the left internal iliac vessels, but not the rectum or urologic structures (Fig. 1). Intravenous pyelography confirmed no involvement of the urologic structures. CT of the thorax and abdomen showed no signs of distant metastasis. Open biopsy performed elsewhere prior to referral to our hospital revealed low-grade MPNST. Total sacrectomy with marginal or wide margins and spinopelvic reconstruction was planned. The patient underwent preoperative embolisation to reduce 80% of the blood supply to the tumour area 2 days prior to the operation. The L5-S1 disc and both sacroiliac joints were to be resected with the sacrum. The patient was placed in the supine position, and a midline longitudinal skin incision was made. Retroperitoneally, the ureters were identified and protected, and the bilateral iliac arteries and veins were ligated and transected. The L5-S1 interverterbral disc was exposed and detached from the L5 endplate. The rectum was mobilised by blunt finger dissection in the presacral area. Abdominal swabs were temporarily packed just anterior to the iliac bones bilaterally to protect important vessels and nerves from posterior ilium osteotomies. The wound was closed and the patient was turned to the prone position. A midline longitudinal incision was made, and the gluteal and paravertebral muscles were dissected from the sacrum and the lower lumbar spine. The sacrospinous and sacrotuberous ligaments were transected bilaterally. After an L5 laminectomy, the dural sac was transected caudal to the L5 nerve roots and double ligated with nonabsorbable sutures. The bilateral L5 and above nerve roots were kept intact. To achieve adequate margins, both ilia were osteotomised, leaving part of the right sacral ala attached to the right anterior sacroiliac joint. The L5-S1 disc was detached from the L5 endplate, and the tumour was removed en bloc. The wound was then washed, and the abdominal swabs were removed. Pedicular screws were inserted into L3, L4, and both sides of the ilia and the right L5 pedicle, and rods were placed in position. A massive (11 cm in length, 25 mm in diameter) freeze-dried humeral allograft filled with antibiotic cement was inserted horizontally between the iliac bones and fixed with 2 partially threaded cancellous screws (Fig. 2). Another small piece (4 cm in length and 1.5 cm in height) of humeral allograft was packed tightly between L5 and the horizontal allograft. Two deep suction drains were inserted. The gluteal muscles were sutured together to cover the reconstruction. The fascia and skin were closed without tension. The total operating
Vol. 22 No. 3, December 2014
Total sacrectomy for nerve sheath tumour 411
(a)
(b)
Figure 2 Spinopelvic reconstruction with structural humeral allografts and a rod–pedicular screw system. (c)
time was 8 hours. Blood loss was 8000 ml, and 17 units of erythrocyte concentrate and 11 units of freshfrozen plasma were transfused. Postoperatively, the patient had weak dorsal flexion of her left ankle and big toe, and a custom-made ankle-foot orthosis was applied. The resected mass with an opaque, whitish cut surface measured 17.0x15.5x12.5 cm and had foci of haemorrhage, cystic changes, and approximately 40% necrosis (Fig. 3). Microscopic examination showed dense spindle cells arranged in a fascicle and herring bone pattern. Oval cells with occasionally buckled nuclei, hyperchromasia, and light eosinophilic cytoplasm were noted. Scattered large atypical cells with hyperchromatic nuclei intermingled with the spindle cell. Approximately 5/10 high-power fields of mitoses were noted (Fig. 3). The surgical margin was uninvolved. Immunohistochemical staining for S-100 protein showed focal positivity in spindle cells, and 20% and 5% of tumour cell nuclei were positive for Ki-67 and p53, respectively (Fig. 3). One week later, the patient developed deep wound infection and underwent debridement and removal of the entire spinopelvic reconstruction (Fig. 4). Wound swab culture grew Staphylococcus aureus. The patient was given intravenous cefazolin for 6
(d)
Figure 3 (a) The tumour is opaque and whitish in colour, with foci of cystic change, haemorrhage, and approximately 40% necrosis, (b) spindle cells are arranged in a fascicle and herring bone pattern, with scattered large atypical cells; oval nuclei and irregular contours with occasional buckle nuclei are noted; and mitoses are 5/10 high-power fields (H&E, x200), (c) immunohistochemical staining for S-100 protein shows focal positive in the spindle cells (x200), and (d) the proliferation index estimated with antibodies against Ki-67 is 20% (x200).
Journal of Orthopaedic Surgery
412 P Kiatisevi et al.
(a)
(b)
(c)
Figure 4 Radiograph of the pelvis after removal of the allografts and spinopelvic reconstruction owing to deep wound infection.
weeks and underwent 2 additional debridements and vacuum-assisted closure. The wound eventually healed after 2 months. As there was no reconstruction of the pelvis, the patient was bed-bound for 2 months. She was able to sit without support at month 3 and able to stand and walk with a walking frame at month 4. At the 18- and 36-month follow-up, the patient had no pain and was able to walk with a walking frame for one and 4 hours, respectively. Although the bilateral L5 and above nerve roots were kept intact, the patient was unable to dorsiflex her right ankle and toes. She managed to use the ankle-foot orthosis well. She had difficulty in urinating and needed intermittent catheterisation, and her anal tone remained flaccid. Her Musculoskeletal Tumor Society score was 21 out of 30. Repeat MRI and CT of the chest showed no recurrence or pulmonary metastasis (Fig. 5). Radiographs of the pelvis showed that the spinal column had sunk down into the pelvis (Fig. 5). CT of the pelvis showed the left transverse processes of L3, L4, and L5 fused to the left ilium and the right transverse processes of L4 and 5 fused to the remaining right sacrum (Fig. 5).
Figure 5 At the 36-month follow-up, (a) magnetic resonance images showing no tumour recurrence, (b) radiographs showing the spinal column sinking to the pelvis, and (c) computed tomography showing the left transverse processes of L3, L4, and L5 fused to the left ilium, and the right transverse processes of L4 and L5 fused to the right sacrum.
DISCUSSION Surgical resection with adequate margins is the treatment of choice for MPNST.6 Although MPNST is generally resistant to chemotherapy and radiotherapy, postoperative radiotherapy is still recommended to increase both disease-free and overall survival.8,9
Vol. 22 No. 3, December 2014
Approximately 20% of MPNSTs are low grade with increased disease-specific survival,6–8 but in one study survival does not correlate with tumour grading.7 One study reported 4 cases of low-grade MPNSTs (3 in lower extremities and one in the retroperitoneum).10 Low-grade MPNST is characterised with moderate cellularity of spindle cells with irregular contours and buckle nuclei with a herring bone pattern, necrosis, mitoses, and focal S-100 protein reactivity.11 Although cellular schwannoma also shows hypercellularity of dense spindle-shaped cells arranged as sweeping fascicles and in a herring bone pattern, necrosis is not common and usually in focal areas only.12 Tumours in the sacral area tend to grow to a considerable size before detection. Sacral neurogenic tumours can be classified according to their growth pattern to determine the appropriate surgical approach.13 A combined anteroposterior approach is recommended for giant neurogenic sacral tumours expanding to the S1 spinal canal.14 The use of the anterior approach to dissect the tumour and ligate the internal iliac vessels (especially the internal iliac arteries) may reduce intra-operative blood loss and complications related to injury to the intrapelvic organs. Ligation of the internal iliac arteries is effective and safe for controlling massive haemorrhage in pelvic surgery because of the multiple sources of collateral blood flow in the pelvis.15–17 Nonetheless, buttock ischaemia secondary to necrosis of the glutei muscles, weakness, and lumbosacral plexopathies have been reported after internal iliac artery ligation for gynaecological surgery, but these complications usually occur in patients with severe aortoiliac vascular disease or risk factors such as insulin-
Total sacrectomy for nerve sheath tumour 413
dependent diabetes mellitus or prior radiotherapy treatment.15 Preoperative embolisation can also reduce intra-operative blood loss and enable complete tumour resection and improved outcome.18,19 Spinopelvic reconstruction after total sacrectomy is necessary for early rehabilitation and ambulation.4,20–24 In our patient, deep infection developed at week 1, and the entire spinopelvic reconstruction was removed. Without spinopelvic reconstruction, the patient was bed-bound for 2 months. The lumbar spine migrated inferiorly and remained between the ilia. The patient was able to walk with a walking frame at month 4. This may be because the muscles and scar tissue between the pelvis and the spine formed a biological sling and eventually stabilised the spine.24 In 9 patients who underwent total sacrectomy through the L5 (n=3) or L5-S1 level (n=6), functional outcome did not differ significantly between patients with (n=4) and without (n=5) reconstruction.24 Nonetheless, spinopelvic stabilisation is still recommended in patients with total sacrectomy and removal of most of both iliac wings.24 For patients without spinopelvic reconstruction, tolerance for sitting, standing, and walking can be improved with the use of a lumbar-sacral corset, as it decreases lumbar-sacral motion, reduces the load on the lumbosacral spine, and reduces excessive lumbar lordosis to provide a straighter and more comfortable low back.25 DISCLOSURE No conflicts of interest were declared by the authors.
REFERENCES 1. Grnja V, Allen WE 3rd, Osborn DJ, Kier EL. Sacral neurofibrosarcoma: an angiographic evaluation. Case report. J Neurosurg 1974;40:767–71. 2. Crosbie DC, Carney PG, Sage MR. Sacral neurofibrosarcoma—a case report. Australas Radiol 1986;30:54–6. 3. Lin PP, Horenstein MG, Healey JH. Sacral mass in a 56-year-old woman. Clin Orthop Relat Res 1997;344:333–7. 4. Min K, Espinosa N, Bode B, Exner GU. Total sacrectomy and reconstruction with structural allografts for neurofibrosarcoma of the sacrum. A case report. J Bone Joint Surg Am 2005;87:864–9. 5. Hruban RH, Shiu MH, Senie RT, Woodruff JM. Malignant peripheral nerve sheath tumors of the buttock and lower extremity. A study of 43 cases. Cancer 1990;66:1253–65. 6. Stucky CC, Johnson KN, Gray RJ, Pockaj BA, Ocal IT, Rose PS, et al. Malignant peripheral nerve sheath tumors (MPNST): the Mayo Clinic experience. Ann Surg Oncol 2012;19:878–85. 7. Ducatman BS, Scheithauer BW, Piepgras DG, Reiman HM, Ilstrup DM. Malignant peripheral nerve sheath tumors. A clinicopathologic study of 120 cases. Cancer 1986;57:2006–21. 8. Kar M, Deo SV, Shukla NK, Malik A, DattaGupta S, Mohanti BK, et al. Malignant peripheral nerve sheath tumors (MPNST)— clinicopathological study and treatment outcome of twenty-four cases. World J Surg Oncol 2006;4:55. 9. Ferner RE, Gutmann DH. International consensus statement on malignant peripheral nerve sheath tumors in neurofibromatosis. Cancer Res 2002;62:1573–7. 10. Yamaguchi U, Hasegawa T, Hirose T, Chuman H, Kawai A, Ito Y, et al. Low grade malignant peripheral nerve sheath tumour:
414 P Kiatisevi et al.
Journal of Orthopaedic Surgery
varied cytological and histological patterns. J Clin Pathol 2003;56:826–30. 11. Trojani M, Contesso G, Coindre JM, Rouesse J, Bui NB, de Mascarel A, et al. Soft-tissue sarcomas of adults; study of pathological prognostic variables and definition of a histopathological grading system. Int J Cancer 1984;33:37–42. 12. White W, Shiu MH, Rosenblum MK, Erlandson RA, Woodruff JM. Cellular schwannoma. A clinicopathologic study of 57 patients and 58 tumors. Cancer 1990;66:1266–75. 13. Klimo P Jr, Rao G, Schmidt RH, Schmidt MH. Nerve sheath tumors involving the sacrum. Case report and classification scheme. Neurosurg Focus 2003;15:E12. 14. Wei G, Xiaodong T, Yi Y, Ji T. Strategy of surgical treatment of sacral neurogenic tumors. Spine (Phila Pa 1976) 2009;34:2587– 92. 15. Shin RK, Stecker MM, Imbesi SG. Peripheral nerve ischaemia after internal iliac artery ligation. J Neurol Neurosurg Psychiatry 2001;70:411–2. 16. Gokaslan ZL, Romsdahl MM, Kroll SS, Walsh GL, Gillis TA, Wildrick DM, et al. Total sacrectomy and Galveston L-rod reconstruction for malignant neoplasms. Technical note. J Neurosurg 1997;87:781–7. 17. Tomita K, Tsuchiya H, Kawahara N, Hata M, Murakami H. En bloc sacrectomy. In: Watkins RG, editor. Surgical approaches to the spine. New York: Springer-Verlag; 2003:205–16. 18. Gottfried ON, Schmidt MH, Stevens EA. Embolization of sacral tumors. Neurosurg Focus 2003;15:E4. 19. Yang HL, Chen KW, Wang GL, Lu J, Ji YM, Liu JY, et al. Pre-operative transarterial embolization for treatment of primary sacral tumors. J Clin Neurosci 2010;17:1280–5. 20. Blatter G, Halter Ward EG, Ruflin G, Jeanneret B. The problem of stabilization after sacrectomy. Arch Orthop Trauma Surg 1994;114:40–2. 21. Tomita K, Tsuchiya H. Total sacrectomy and reconstruction for huge sacral tumors. Spine (Phila Pa 1976) 1990;15:1223–7. 22. Shikata J, Yamamuro T, Kotoura Y, Mikawa Y, Iida H, Maetani S. Total sacrectomy and reconstruction for primary tumors. Report of two cases. J Bone Joint Surg Am 1988;70:122–5. 23. Kawahara N, Murakami H, Yoshida A, Sakamoto J, Oda J, Tomita K. Reconstruction after total sacrectomy using a new instrumentation technique: a biomechanical comparison. Spine (Phila Pa 1976) 2003;28:1567–72. 24. Wuisman P, Lieshout O, Sugihara S, van Dijk M. Total sacrectomy and reconstruction: oncologic and functional outcome. Clin Orthop Relat Res 2000;381:192–203. 25. Guo Y, Yadav R. Improving function after total sacrectomy by using a lumbar-sacral corset. Am J Phys Med Rehabil 2002;81:72–6.
