Brain Tumor Res Treat.  2017 Oct;5(2):116-119. 10.14791/btrt.2017.5.2.116.

Subfrontal Schwannoma Extended Broadly to Nasal Cavity Treated by Gamma Knife Radiosurgery Following Surgical Excision: A Case Report

• Kim SH
• Lee JH
• Sung SK
• Choi CH

• KMID: 2396457
• DOI: http://doi.org/10.14791/btrt.2017.5.2.116

Abstract

Subfrontal schwannomas are rarely reported. They are usually found only in the subfrontal area, but some extend to the nasal cavity. In these cases, prevention of postoperative cerebrospinal fluid (CSF) leakage through thinned or eroded anterior skull base is important. A 51-year-old female with anosmia and mild nausea was diagnosed as subfrontal extraaxial mass with nasal cavity extension. This mass was initially thought to be an olfactory groove meningioma. We performed a bifrontal craniotomy for surgical excision. We did not totally remove the tumor, as we wanted to prevent a skull base defect. The histopathological diagnosis was a schwannoma. There was no postoperative complication such as CSF leakage. The residual tumor was treated with gamma knife radiosurgery. The nasal cavity mass has not grown as of five years after radiosurgery.

Keyword

Schwannoma; Olfactory nerve; Cerebrospinal fluid leakage

MeSH Terms

Cerebrospinal Fluid
Cerebrospinal Fluid Leak
Craniotomy
Cytochrome P-450 CYP1A1
Diagnosis
Female
Humans
Meningioma
Middle Aged
Nasal Cavity*
Nausea
Neoplasm, Residual
Neurilemmoma*
Olfaction Disorders
Olfactory Nerve
Postoperative Complications
Radiosurgery*
Skull Base
Cytochrome P-450 CYP1A1

Figure

• 

  Fig. 1 Coronal and sagittal magnetic resonance imaging with gadolinium shows an extra-axial mass at anterior cranial fossa. The tumor extends to the nasal cavity. However, the tumor does not extend to the optic canal. Neither olfactory nerves is identified.

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  Fig. 2 Coronal and sagittal reconstruction images of computed tomography scan reveal bony thinning or erosion on anterior skull base (white arrows).

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  Fig. 3 Photomicrographs of the tumor show spindle-shaped cells with elongated nuclei and palely eosinophil cytoplasm. Pathologic diagnosis is schwannoma (hematoxylin and eosin staining, ×400).

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  Fig. 4 MRIs after one day and five years postoperatively. A: Postoperative MRIs with gadolinium at postoperative a day show a remnant mass at the thinned skull base. B: MRIs with gadolinium after five years reveal no tumor growth and widening of nasal cavity. The tumor is well controlled. MRI, magnetic resonance imaging.

Reference

1. Kim DY, Yoon PH, Kie JH, Yang KH. The olfactory groove schwannoma attached to the cribriform plate: a case report. Brain Tumor Res Treat. 2015; 3:56–59.

2. Kanaan HA, Gardner PA, Yeaney G, et al. Expanded endoscopic endonasal resection of an olfactory schwannoma. J Neurosurg Pediatr. 2008; 2:261–265.

3. Bezircioğlu H, Sucu HK, Rezanko T, Minoğlu M. Nasal-subfrontal giant schwannoma. Turk Neurosurg. 2008; 18:412–414.

4. Amador AR, Santonja C, Del Pozo JM, Ortiz L. Olfactory schwannoma. Eur Radiol. 2002; 12:742–744.

5. Choi YS, Sung KS, Song YJ, Kim HD. Olfactory schwannoma-case report. J Korean Neurosurg Soc. 2009; 45:103–106.

6. Liu JK, Eloy JA. Expanded endoscopic endonasal transcribriform approach for resection of anterior skull base olfactory schwannoma. Neurosurg Focus. 2012; 32:Suppl 1. E3.

7. Elsharkawy M, Xu Z, Schlesinger D, Sheehan JP. Gamma Knife surgery for nonvestibular schwannomas: radiological and clinical outcomes. J Neurosurg. 2012; 116:66–72.

8. Puataweepong P, Dhanachai M, Hansasuta A, et al. Clinical outcomes of intracranial nonvestibular schwannomas treated with linac-based stereotactic radiosurgery and radiotherapy. Asian Pac J Cancer Prev. 2016; 17:3271–3276.

9. Yamahata H, Hirahara K, Tomosugi T, et al. Subfrontal schwannoma mimicking neuroblastoma: case report. Skull Base Rep. 2011; 1:59–64.

10. Adachi K, Yoshida K, Miwa T, Ikeda E, Kawase T. Olfactory schwannoma. Acta Neurochir (Wien). 2007; 149:605–610.