Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jun 26;5(26):CASE23175.
doi: 10.3171/CASE23175. Print 2023 Jun 26.

Internal iliac artery aneurysm masquerading as a sciatic nerve schwannoma: illustrative case

Lokeshwar S Bhenderu  1 , Khaled M Taghlabi  1 , Taimur Hassan  1 , Jaime R Guerrero  1 , Jesus G Cruz-Garza  1 , Rachel L Goldstein  2 , Shashank Sharma  3 , Linda V Le  3 , Tue A Dinh  2 , Amir H Faraji  1
Affiliations

Internal iliac artery aneurysm masquerading as a sciatic nerve schwannoma: illustrative case

Lokeshwar S Bhenderu et al. J Neurosurg Case Lessons. .

Abstract

Background: Schwannomas are common peripheral nerve sheath tumors. Imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) can help to distinguish schwannomas from other types of lesions. However, there have been several reported cases describing the misdiagnosis of aneurysms as schwannomas.

Observations: A 70-year-old male with ongoing pain despite spinal fusion surgery underwent MRI. A lesion was noted along the left sciatic nerve, which was believed to be a sciatic nerve schwannoma. During the surgery for planned neurolysis and tumor resection, the lesion was noted to be pulsatile. Electromyography mapping and intraoperative ultrasound confirmed vascular pulsations and turbulent flow within the aneurysm, so the surgery was aborted. A formal CT angiogram revealed the lesion to be an internal iliac artery (IIA) branch aneurysm. The patient underwent coil embolization with complete obliteration of the aneurysm.

Lessons: The authors report the first case of an IIA aneurysm misdiagnosed as a sciatic nerve schwannoma. Surgeons should be aware of this potential misdiagnosis and potentially use other imaging modalities to confirm the lesion before proceeding with surgery.

Keywords: iliac artery aneurysm; schwannoma; sciatic nerve.

PubMed Disclaimer

Conflict of interest statement

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Figures

FIG. 1.
FIG. 1.
Abdomen and pelvis coronal (A) and axial (B) T1-weighted and sagittal T2-weighted (C) MRI without contrast depicting the lesion (red arrows).
FIG. 2.
FIG. 2.
A: Intraoperative image of the lesion after transgluteal dissection. B: Intraoperative ultrasound showing turbulent flow within the lesion.
FIG. 3.
FIG. 3.
Abdomen and pelvis CT angiography without (A) and with (B) contrast showing enhanced contrast uptake.
FIG. 4.
FIG. 4.
Follow-up abdomen and pelvis CTA, sagittal (A) and axial (B) views, showing successful embolization of the aneurysm sac.
See this image and copyright information in PMC

References

    1. Hilton DA, Hanemann CO. Schwannomas and their pathogenesis. Brain Pathol. 2014;24(3):205–220. - PMC - PubMed
    1. Telera S, Raus L, Vietti V, et al. Schwannomas of the sciatic nerve: a rare and neglected diagnosis. A review of the literature with two illustrative cases. Clin Neurol Neurosurg. 2020;195:105889. - PubMed
    1. Albert P, Patel J, Badawy K, et al. Peripheral nerve schwannoma: a review of varying clinical presentations and imaging findings. J Foot Ankle Surg. 2017;56(3):632–637. - PubMed
    1. Omezzine SJ, Zaara B, Ben Ali M, Abid F, Sassi N, Hamza HA. A rare cause of non discal sciatica: schwannoma of the sciatic nerve. Orthop Traumatol Surg Res. 2009;95(7):543–546. - PubMed
    1. Chee DW, Peh WC, Shek TW. Pictorial essay: imaging of peripheral nerve sheath tumours. Can Assoc Radiol J. 2011;62(3):176–182. - PubMed

LinkOut - more resources