Intrapelvic sciatic notch schwannoma: microsurgical excision using the infragluteal approach

Case report

Restricted access

Benign neurogenic tumors at the sciatic notch that are purely intrapelvic have rarely been reported. Because of this tumor's particular position, a transabdominal or combined transabdominal-gluteal approach is usually used to achieve total resection. However, the transabdominal approach carries a remarkable surgical risk because of the manipulation of intraperitoneal organs. Here, the authors describe a 59-year-old woman harboring a purely intrapelvic sciatic notch schwannoma extrinsic to the sciatic nerve, which was totally removed via the infragluteal approach preserving sciatic function. The postoperative course was uneventful. The infragluteal approach can be safely used for the effective resection of intrapelvic benign neurogenic tumors at the sciatic notch that are extrinsic to the sciatic nerve, avoiding the more invasive and risky transabdominal approach.

Article Information

Address correspondence to: Quintino Giorgio D'Alessandris, M.D., Department of Neurosurgery, Catholic University School of Medicine, Largo Agostino Gemelli, 8, Rome 00168, Italy. email: giorgiodal@hotmail.it.

Please include this information when citing this paper: published online April 12, 2013; DOI: 10.3171/2013.3.JNS121161.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Axial (left) and coronal (right) pelvic CT scans showing an intrapelvic rounded mass at the entry of the left sciatic notch. Asterisks indicate tumor. AR = acetabular roof; Co = coccyx; GM = gluteus maximus; Gm = gluteus minimus; IA = internal iliac artery; IPs = iliopsoas muscle; IR = ischial ramus; Pi = piriformis muscle; PV = internal pudendal vein; RM = rectus abdominis muscle; Sa = sacrum.

  • View in gallery

    Preoperative axial (A) and coronal (B) T2-weighted pelvic MR images showing a dishomogeneous hyperintense ovoid mass under the piriformis muscle at the left sciatic notch. Three-month postoperative axial (C) and coronal (D) T2-weighted pelvic MR images showing complete removal of the tumor and the normal course of sciatic nerve. Asterisks indicate tumor. AIIS = anterior inferior iliac spine; I = ilium; IT = ischial tuberosity; Me = mesentery; Re = rectum; SN = sciatic nerve; SP = sacral plexus.

  • View in gallery

    High-magnification intraoperative views. A and B: Progressive dissection of the schwannoma. C: Complete tumor removal.

  • View in gallery

    Photomicrographs obtained for pathological examination of the tumor. Left: The tumor is characterized by the presence of spindle cell areas (white asterisk) with palisaded arrangement and double rows of nuclei separated by eosinophilic material, termed “Verocay bodies” (inset), alternating with loosely textured areas (black asterisk) mimicking a neurofibroma. H & E, original magnification ×100. Right: On immunohistochemistry a diffuse and uniform nuclear and cytoplasmic staining for S100 protein was observed in all tumor cells, supporting the diagnosis of schwannoma. Original magnification ×100.

  • View in gallery

    Schematic drawings of axial pelvic sections to show the relationships between the tumors and the width of the sciatic notch. A: Spinner et al. Case 1. B: Consales et al. case. C: The present case (as seen in Fig. 1 left). Notice that the sciatic notch (yellow oval) width was the smallest in the present case (6 cm vs 8.5 cm in the Spinner case and 6.5 cm in the Consales case). Asterisk indicates tumor (blue). Printed with the permission of Quintino Giorgio D'Alessandris, 2013.

References

1

Cohen BALanzieri CFMendelson DSSacher MHermann GTrain JS: CT evaluation of the greater sciatic foramen in patients with sciatica. AJNR Am J Neuroradiol 7:3373421986

2

Consales APoppi MStumpo M: Sciatic schwannoma spanning the sciatic notch: removal by an anterior, transabdominal approach. Br J Neurosurg 20:46482006

3

Donner TRVoorhies RMKline DG: Neural sheath tumors of major nerves. J Neurosurg 81:3623731994

4

Filler AGHaynes JJordan SEPrager JVillablanca JPFarahani K: Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment. J Neurosurg Spine 2:991152005

5

Harrison MJLeis HTJohnson BAMacDonald WDGoldman CD: Hemangiopericytoma of the sciatic notch presenting as sciatica in a young healthy man: case report. Neurosurgery 37:120812121995

6

Kelso TBFerrari CJFrassica FJ: Sciatica caused by a neurilemoma of the intrapelvic portion of the sciatic nerve. A case report. J Bone Joint Surg Am 75:6036051993

7

Kieser DCTheis JCVan Rij AM: A combined approach to the excision of sciatic notch dumb-bell tumours. ANZ J Surg 81:6502011. (Letter)

8

Long DMBenDebba MTorgerson WSBoyd RJDawson EGHardy RW: Persistent back pain and sciatica in the United States: patient characteristics. J Spinal Disord 9:40581996

9

Patil PGFriedman AH: Surgical exposure of the sciatic nerve in the gluteal region: anatomic and historical comparison of two approaches. Neurosurgery 56:1 Suppl1651712005

10

Revell MPGrimer RJ: How to remove a dumbbell tumour of the sciatic notch. Sarcoma 4:61622000

11

Socolovsky MGarategui LCampero AConesa HBasso A: Exposure of the sciatic nerve in the gluteal region without sectioning the gluteus maximus: an anatomical and microsurgical study. Acta Neurochir Suppl 108:2332402011

12

Spinner RJEndo TAmrami KKDozois EJBabovic-Vuksanovic DSim FH: Resection of benign sciatic notch dumbbell-shaped tumors. J Neurosurg 105:8738802006

13

Stookey BP: The technic of nerve suture. JAMA 74:138013851920

14

Thomas JEPiepgras DGScheithauer BOnofrio BMShives TC: Neurogenic tumors of the sciatic nerve. A clinicopathologic study of 35 cases. Mayo Clin Proc 58:6406471983

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 123 123 42
Full Text Views 156 156 29
PDF Downloads 213 213 14
EPUB Downloads 0 0 0

PubMed

Google Scholar