Skull Base Rep 2011; 1(1): 059-064
DOI: 10.1055/s-0031-1275637
© Thieme Medical Publishers

Subfrontal Schwannoma Mimicking Neuroblastoma: Case Report

Hitoshi Yamahata1 , Kazuho Hirahara1 , Tetsuzou Tomosugi1 , Masahiko Yamada1 , Takeshi Ishii1 , Takashi Ishigami1 , Koichi Uetsuhara1 , Kazunobu Sueyoshi2 , Sumika Matsukida2 , Kazutaka Yatsushiro3 , Kazunori Arita3
  • 1Department of Neurosurgery, Kagoshima City Hospital, Kagoshima, Japan
  • 2Department of Clinical Pathology, Kagoshima City Hospital, Kagoshima, Japan
  • 3Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
Further Information

Hitoshi YamahataM.D. 

Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University

8-35-1 Sakuragaoka, Kagoshim-shi, Kagoshima 890-8520, Japan

Email: yamahata-nsu@umin.net

Publication History

Publication Date:
25 March 2011 (online)

Table of Contents #

ABSTRACT

Computed tomography (CT), performed in a healthy 28-year-old man after minor head injury, detected a frontal base tumor. Neurological examination revealed left hyposmia. On magnetic resonance imaging scans, there was a heterogeneously enhanced tumor located in the left paramedian frontal base with extension into the left ethmoid sinus. Angiography showed a hypervascular mass in the left anterior cranial fossa; it was mainly fed by the left ethmoidal artery. Positron emission tomography scanning showed moderate accumulation of 11-methylmethionine and low accumulation of 18-fluorodeoxyglucose (FDG) at the tumor site. Bone image CT disclosed compressive, nondestructive deformation of the left frontal base. The preoperative diagnosis was olfactory neuroblastoma or meningioma. The tumor was totally resected via bifrontal craniotomy. The tumor was histologically diagnosed as typical schwannoma; it was positive for S-100 protein. We report a rare subfrontal schwannoma with extension into the nasal cavity that mimicked neuroblastoma. Low FDG accumulation and compressive deformation of the anterior skull base may help in the differential diagnosis of these tumors.

Schwannomas arise from the nerve sheaths of peripheral and cranial nerves. They account for 6 to 8% of all intracranial tumors.[1] [2] They commonly arise from the vestibular nerve and less commonly from the fifth, ninth, and tenth cranial nerves. Schwannomas of the olfactory groove or subfrontal region are rare; 49 cases have been reported to date.[3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] Because of their rarity, these tumors can be misdiagnosed preoperatively as meningioma or olfactory neuroblastoma. We report a rare anterior cranial fossa schwannoma with extension into the ethmoid sinus and highlight factors that can contribute to the preoperative differential diagnosis of these tumors.

#

CASE REPORT

This 28-year-old man underwent computed tomography (CT) after a minor head injury. It revealed a tumor at the anterior skull base. His neurological and general examinations were normal except for left hyposmia. The results of intravenous olfaction tests were within normal limits.

T2-weighted magnetic resonance images (MRI) revealed a subfrontal tumor; it was hyperintense and iso-mixed intense to the white matter (Fig. [1A]). It extended into the left ethmoid sinus and was hypointense on T1-weighted images and heterogeneously enhanced (Fig. [1B]). Coronal bone CT showed thinning of the left cribriform plate and medial endofrontal fovea with marked compression in the direction of the nasal cavity (Fig. [1C]). A left carotid angiogram disclosed a hypervascular mass in the base of the anterior cranial fossa mainly; it was fed by the left anterior ethmoidal artery and displaced the anterior cerebral artery upward (Fig. [2]). Positron emission tomography (PET) scanning with 18-fluorodeoxyglucose (FDG) and 11-methylmethionine was performed to rule out metastatic disease and carcinoma of the ethmoid sinus (Fig. [3]). Methionine PET revealed moderate accumulation of the tracer compared with surrounding cerebral tissue; the tumor was depicted as a low-accumulation area on FDG PET. The preoperative diagnosis included neuroblastoma and olfactory groove meningioma.

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Figure 1 (A) Axial T2-weighted magnetic resonance imaging (MRI) revealing a subfrontal heterogeneously hyperintense mass. (B) Sagittal MRI with gadolinium demonstrating an enhanced subfrontal mass with extension to the ethmoid sinus. (C) Coronal computed tomography showing erosion of the left cribriform plate.

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Figure 2 Digital subtraction angiogram with left internal carotid artery injection showing the hypertrophic ophthalmic artery feeding the subfrontal mass.

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Figure 3 (A) Methionine positron emission tomography (PET) imaging showing a moderate-attenuation lesion in the frontal lobe. (B) The tumor was not identified on fluorodeoxyglucose PET.

We performed bifrontal craniotomy. Upon opening the dura mater, on the left frontal lobe we found an extra-axial mass partially attached to the dura of the left frontal base. It was elastic, hard, and hypervascular. After cauterization of the large feeding artery arising from the cribriform plate, we performed internal decompression. The tumor was separated from arachnoid tissue covering the frontal lobe. The dura mater of the frontal base was thin and almost absent at the lowermost part of the tumor. The bone of the frontal base was depressed toward the nasal cavity; however, the bone cortex was preserved. The left olfactory nerve was thinned and stretched medially but anatomically preserved. The tumor did not attach to the falx. It was totally resected. The defect in the left frontal base was filled with abdominal fat and covered with a periosteal flap secured with fibrin glue. The craniotomy was closed and dressed in standard fashion. Postoperative MRI confirmed total resection of the tumor (Fig. [4]).

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Figure 4 Postoperative magnetic resonance imaging with gadolinium demonstrating total resection of the tumor and a small hemorrhagic scar at the tumor site.

Histological examination disclosed proliferation of spindle cells with columnar nuclei exhibiting a fascicular pattern and focal nuclear palisading (Fig. [5]). Loose myxoid stroma and hyalinized vessels were also noted. Some areas of fibrosis with calcification and vascular proliferation were noted. There was no necrosis or cellular atypia. Immunohistochemical staining revealed tumor-cell positivity for S-100 and CD57.

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Figure 5 Histopathologic examination of the surgical specimen showed that the tumor consisted of alternating areas of compact, elongated cells (Antoni type A) and less cellularized areas (Antoni type B) (hematoxylin and eosin; A × 50, B × 100). On immunohistochemical staining, the tumor cells were positive for S-100 protein (C) (×100).

The patient's hyposmia improved postoperatively, and he was discharged without any neurological deficit at 19 days after the operation.

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DISCUSSION

Schwannomas are benign, slowly growing nerve sheath tumors that usually arise from peripheral nerves containing Schwann cells, including distal portions of the cranial nerve. The tumor in our patient was located in the subfrontal subdural space adjacent to the olfactory tract. As the olfactory nerve does not have a Schwann cell layer, theoretically, schwannoma cannot arise at this nerve.[18] [19] Hypotheses on the possible origin of subfrontal schwannoma focus on developmental and nondevelopmental origins.[15] [19] The developmental hypothesis proposes that they arise from aberrant Schwann cells. Others suggested that these tumors originate from either multipotent mesenchymal cells or displaced neural crest cells that form foci of Schwann cells, termed schwannosis, within the central nervous system parenchyma.[27] [28] The nondevelopmental hypothesis proposes that Schwann cells in perivascular nerve plexi surrounding cerebral arterioles and large arteries in the subarachnoid space develop into schwannomas.[29] Schwann cells are also seen in association with meningeal branches of the trigeminal and anterior ethmoidal nerves innervating the anterior cranial fossa and olfactory groove. In our case, the tumor was attached to the dura of the frontal base and grew upward and toward the ethmoid sinus without destroying the bone cortex. Therefore, we concluded that its most likely origin was the meningeal branch of the trigeminal nerve on the dura mater of the frontal base.

Including our patient, there are 49 reported cases of subfrontal or olfactory groove schwannomas.[3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] Of these, three occurred in patients with neurofibromatosis.[19] The patients' age ranged from 14 to 63 years (average 33 years) with a 2:1 male predominance. These tumors are different from meningiomas arising in the same area in that meningiomas are seen in older age groups and meningiomas are different from schwannomas arising at other sites where there is a female predominance.[19] Patients usually present with headache, seizures, anosmia, frontal lobe dysfunction, and signs and symptoms related to elevated intracranial pressure.[16] [19]

As shown in Table [1], of the 49 documented schwannomas, 16 (33%) extended into the nasal cavity.[6] [7] [8] [10] [12] [13] [19] [21] [23] [24] [26] They included four intranasal schwannomas that extended into the anterior cranial fossa.[6] [7] [8] [10] Radiographic features of the frontal base were bony erosion (n = 6) and bony destruction (n = 2). With the exception of tumors preoperatively diagnosed by biopsy, they were preoperatively misdiagnosed as neuroblastoma, sinonasal malignancy, infectious disease, and meningioma. Our preoperative misdiagnosis of olfactory neuroblastoma or meningioma was based on radiological findings of extension into the nasal cavity and hypervascularity.

Table 1 Summary of Reported Cases of Subfrontal or Olfactory Schwannoma with Extension to Nasal Cavity
No.First Author/YearAge/SexThe Bone of the Frontal BasePreoperative DiagnosisRemarks
1Von Strum/1968[3] 27/MNDND
2Mauro/1983[35] 44/MBony erosionND
3Zovickian/1986[6] 40/MNDPreoperative biopsyNasal schwannoma
4Nagao/1991[36] 63/FNDND
5Enion/1991[7] 28/MNDNDNasal schwannoma
6Bando/1992[37] 55/FNDND
7Harada/1992[38] 33/MNDMeningioma
8Bavetta/1993[8] 41/MBony destructionPreoperative biopsyNasal schwannoma
9Gatsher/1998[39] 50/FNDNDNasal schwannoma
10Carron/2002[12] 59/FBony erosionNeuroblastoma/sinonasal malignancy
11de Souza/2002[13] 27/MNDInfectious disease
12Bezircioglu/2008[40] 33/FBony destructionPreoperative biopsy
13Kanaan/2008[23] 14/MBony erosionPreoperative biopsyEndonasal resection
14Mirone/2009[26] 38/MBony erosionND
15Choi/2009[24] 39/FBony erosionND
16Present case28/MBony erosionNeuroblastoma/meningiomaHypervascular
ND, not described.

The differential diagnosis of tumors involving the extra-axial anterior cranial fossa and cribriform plate with extension to the ethmoid sinus should include meningioma, schwannoma, olfactory neuroblastoma, and metastatic disease.[16] [17] [19] [24] Among these differential diagnoses, neuroblastoma outranked schwannoma based on imaging features and the sex and age distribution of neuroblastoma.[16] However, the correct diagnosis of schwannoma is essential because neuroblastomas require more aggressive craniofacial resection.[16] [30] Neuroblastoma and ethmoid carcinoma can invade the paranasal sinuses and cause marked bony destruction.[16] [20] [31] [32] On the other hand, schwannomas are slow-growing tumors characterized by expansion and thinning of the confining bone.[6] [19] In our case, intraoperative findings were sufficient for a diagnosis of benign tumor because the lesion manifested a well-demarcated margin and there was no bone destruction. The absence of bone destruction may represent a strong radiological clue for the differentiation between olfactory neuroblastoma and other benign diseases.

Yu et al reported an esthesioneuroblastoma that revealed strong 18-FDG uptake on PET scans and, as in our case, Sakamoto et al found that schwannoma could not be identified on the same modality.[33] [34] Ours is the first methionine PET study of a subfrontal schwannoma; by this modality, it was revealed as an area with moderate tracer accumulation, indicating that PET yields useful information on the proliferative nature of tumors that is essential for the differential diagnosis of subfrontal tumors.

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CONCLUSION

We reported a rare case of subfrontal schwannoma with extension into the nasal cavity. We posit that its origin was the meningeal branch of the trigeminal nerve in the frontal base. Subfrontal schwannoma should be included in the differential diagnosis of tumors of the anterior cranial fossa with extension into the nasal cavity.

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REFERENCES

  • 1 New P FJ. Intracerebral schwannoma. Case report.  J Neurosurg. 1972;  36 795-797
  • 2 Russell D S, Rubinstein J L. Pathology of Tumors of the Nervous System. 5th ed. Baltimore: Williams & Wilkins; 1989: 537-560
  • 3 Von Strum K W, Bonis G, Kosmaoglou V. Ube rein neurinoma der lamina cribrosa.  Zbl Neurochir. 1968;  29 217-222
  • 4 Viale E S, Pau A, Turtas S. Olfactory groove neurinomas: case report.  J Neurosurg Sci. 1973;  17 193-196
  • 5 Auer R N, Budny J, Drake C G, Ball M J. Frontal lobe perivascular schwannoma. Case report.  J Neurosurg. 1982;  56 154-157
  • 6 Zovickian J, Barba D, Alksne J F. Intranasal schwannoma with extension into the intracranial compartment: case report.  Neurosurgery. 1986;  19 813-815
  • 7 Enion D S, Jenkins A, Miles J B, Diengdoh J V. Intracranial extension of a naso-ethmoid schwannoma.  J Laryngol Otol. 1991;  105 578-581
  • 8 Bavetta S, McFall M R, Afshar F, Hutchinson I. Schwannoma of the anterior cranial fossa and paranasal sinuses.  Br J Neurosurg. 1993;  7 697-700
  • 9 Deogaonkar M, Goel A, Nagpal R D, Desai A P. Intraparenchymal schwannoma of the frontal lobe.  J Postgrad Med. 1994;  40 218-219
  • 10 Gatscher S, Love S, Coakham H B. Giant nasal schwannoma with intracranial extension. Case illustration.  J Neurosurg. 1998;  89 161
  • 11 Gelabert M, Fernández J, López E. Schwannoma of the olfactory groove.  Neurologia. 2000;  15 404-405 [Spanish, with Eng abstract]
  • 12 Carron J D, Singh R VP, Karakla D W, Silverberg M. Solitary schwannoma of the olfactory groove: case report and review of the literature.  Skull Base Rep. 2002;  12 163-166
  • 13 de Souza H L, Ramos A M, Ramos C C et al.. Olfactory groove schwannoma: case report.  Arq Neuropsiquiatr. 2003;  61 125-128 [Portuguese, with Eng abstract]
  • 14 Prasad D, Jalali R, Shet T. Intracranial subfrontal schwannoma treated with surgery and 3D conformal radiotherapy.  Neurol India. 2004;  52 248-250
  • 15 Sano H, Hayashi Y, Hasegawa M, Yamashita J. Subfrontal schwannoma without hyposmia—case report.  Neurol Med Chir (Tokyo). 2004;  44 591-594
  • 16 Yako K, Morita A, Ueki K, Kirino T. Subfrontal schwannoma.  Acta Neurochir (Wien). 2005;  147 655-657 discussion 657-658
  • 17 Ahmad F U, Gupta A, Sharma M C, Shukla G, Mehta V S. The enigmatic origin of subfrontal schwannomas: report of a case without hyposmia.  Acta Neurochir (Wien). 2006;  148 671-672 discussion 672
  • 18 Yasuda M, Higuchi O, Takano S, Matsumura A. Olfactory ensheathing cell tumor: a case report.  J Neurooncol. 2006;  76 111-113
  • 19 Adachi K, Yoshida K, Miwa T, Ikeda E, Kawase T. Olfactory schwannoma.  Acta Neurochir (Wien). 2007;  149 605-610 discussion 610-611
  • 20 Santhosh K, Kesavadas C, Radhakrishnan V V, Thomas B, Kapilamoorthy T R, Gupta A K. Usefulness of T2*-weighted MR sequence for the diagnosis of subfrontal schwannoma.  J Neuroradiol. 2007;  34 330-333
  • 21 Bezircioğlu H, Sucu H K, Rezanko T, Minoğlu M. Nasal-subfrontal giant schwannoma.  Turk Neurosurg. 2008;  18 412-414
  • 22 Daglioglu E, Okay O, Dalgic A, Albayrak A L, Ergungor F. Cystic olfactory schwannoma of the anterior cranial base.  Br J Neurosurg. 2008;  22 697-699
  • 23 Kanaan H A, Gardner P A, Yeaney G et al.. Expanded endoscopic endonasal resection of an olfactory schwannoma.  J Neurosurg Pediatr. 2008;  2 261-265
  • 24 Choi Y S, Sung K S, Song Y J, Kim H D. Olfactory schwannoma-case report-.  J Korean Neurosurg Soc. 2009;  45 103-106
  • 25 Martínez-Soto L, Alfaro-Baca R, Torrecilla-Sardón M V, Fernández-Vallejo B, Ferreira-Muñóz R, De Diego T. A new case of “olfactory schwannoma”; presentation and literature review.  Neurocirugia (Astur). 2009;  20 294-297
  • 26 Mirone G, Natale M, Scuotto A, Rotondo M. Solitary olfactory groove schwannoma.  J Clin Neurosci. 2009;  16 454-456
  • 27 Redekop G, Elisevich K, Gilbert J. Fourth ventricular schwannoma. Case report.  J Neurosurg. 1990;  73 777-781
  • 28 Frim D M, Ogilvy C S, Vonsattal J P, Chapman P H. Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review.  Pediatr Neurosurg. 1992;  18 190-194
  • 29 Nelson E, Rennels M. Innervation of intracranial arteries.  Brain. 1970;  93 475-490
  • 30 Kim H J, Cho H J, Kim K S et al.. Results of salvage therapy after failure of initial treatment for advanced olfactory neuroblastoma.  J Craniomaxillofac Surg. 2008;  36 47-52
  • 31 Burke D P, Gabrielsen T O, Knake J E, Seeger J F, Oberman H A. Radiology of olfactory neuroblastoma.  Radiology. 1980;  137 367-372
  • 32 Ichikawa M, Nakazawa T, Nioka H, Matsuda M, Handa J. Olfactory neuroblastoma with intracranial extension. Report of two cases.  Neurol Med Chir (Tokyo). 1989;  29 902-907 [Japanese, with Eng abstract]
  • 33 Yu J, Koch C A, Patsalides A et al.. Ectopic Cushing's syndrome caused by an esthesioneuroblastoma.  Endocr Pract. 2004;  10 119-124
  • 34 Sakamoto H, Nakai Y, Matsuda M et al.. Positron emission tomographic imaging of acoustic neuromas.  Acta Otolaryngol Suppl. 2000;  542 18-21
  • 35 Mauro A, Sciolla R, Sicuro L, Ponzio R. Solitary neurinoma of the anterior cranial fossa: case report.  J Neurosurg Sci. 1983;  27 45-49
  • 36 Nagao S, Aoki T, Kondo S, Gi H. Subfrontal schwannoma: a case report.  No Shinkei Geka. 1991;  19 47-51 [Japanese, with English abstract]
  • 37 Bando K, Obayashi M, Tsuneharu F. A case of subfrontal schwannoma.  No Shinkei Geka. 1992;  20 1189-1194 [Japanese, with English abstract]
  • 38 Harada T, Kawauchi M, Watanabe M, Kyoshima K, Kobayashi S. Subfrontal schwannoma—case report.  Neurol Med Chir. 1992;  32 957-960
  • 39 Gatsher S, Love S, Coakham H B. Giant nasal schwannoma with intracranial extension.  J Neurosurg. 1998;  89 161
  • 40 Bezircioglu H, Sucu H K, Rezanko T, Minoglu M. Nasal-subfrontal giant schwannoma.  Turkish Neurosurg. 2008;  18 412-414

Hitoshi YamahataM.D. 

Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University

8-35-1 Sakuragaoka, Kagoshim-shi, Kagoshima 890-8520, Japan

Email: yamahata-nsu@umin.net

#

REFERENCES

  • 1 New P FJ. Intracerebral schwannoma. Case report.  J Neurosurg. 1972;  36 795-797
  • 2 Russell D S, Rubinstein J L. Pathology of Tumors of the Nervous System. 5th ed. Baltimore: Williams & Wilkins; 1989: 537-560
  • 3 Von Strum K W, Bonis G, Kosmaoglou V. Ube rein neurinoma der lamina cribrosa.  Zbl Neurochir. 1968;  29 217-222
  • 4 Viale E S, Pau A, Turtas S. Olfactory groove neurinomas: case report.  J Neurosurg Sci. 1973;  17 193-196
  • 5 Auer R N, Budny J, Drake C G, Ball M J. Frontal lobe perivascular schwannoma. Case report.  J Neurosurg. 1982;  56 154-157
  • 6 Zovickian J, Barba D, Alksne J F. Intranasal schwannoma with extension into the intracranial compartment: case report.  Neurosurgery. 1986;  19 813-815
  • 7 Enion D S, Jenkins A, Miles J B, Diengdoh J V. Intracranial extension of a naso-ethmoid schwannoma.  J Laryngol Otol. 1991;  105 578-581
  • 8 Bavetta S, McFall M R, Afshar F, Hutchinson I. Schwannoma of the anterior cranial fossa and paranasal sinuses.  Br J Neurosurg. 1993;  7 697-700
  • 9 Deogaonkar M, Goel A, Nagpal R D, Desai A P. Intraparenchymal schwannoma of the frontal lobe.  J Postgrad Med. 1994;  40 218-219
  • 10 Gatscher S, Love S, Coakham H B. Giant nasal schwannoma with intracranial extension. Case illustration.  J Neurosurg. 1998;  89 161
  • 11 Gelabert M, Fernández J, López E. Schwannoma of the olfactory groove.  Neurologia. 2000;  15 404-405 [Spanish, with Eng abstract]
  • 12 Carron J D, Singh R VP, Karakla D W, Silverberg M. Solitary schwannoma of the olfactory groove: case report and review of the literature.  Skull Base Rep. 2002;  12 163-166
  • 13 de Souza H L, Ramos A M, Ramos C C et al.. Olfactory groove schwannoma: case report.  Arq Neuropsiquiatr. 2003;  61 125-128 [Portuguese, with Eng abstract]
  • 14 Prasad D, Jalali R, Shet T. Intracranial subfrontal schwannoma treated with surgery and 3D conformal radiotherapy.  Neurol India. 2004;  52 248-250
  • 15 Sano H, Hayashi Y, Hasegawa M, Yamashita J. Subfrontal schwannoma without hyposmia—case report.  Neurol Med Chir (Tokyo). 2004;  44 591-594
  • 16 Yako K, Morita A, Ueki K, Kirino T. Subfrontal schwannoma.  Acta Neurochir (Wien). 2005;  147 655-657 discussion 657-658
  • 17 Ahmad F U, Gupta A, Sharma M C, Shukla G, Mehta V S. The enigmatic origin of subfrontal schwannomas: report of a case without hyposmia.  Acta Neurochir (Wien). 2006;  148 671-672 discussion 672
  • 18 Yasuda M, Higuchi O, Takano S, Matsumura A. Olfactory ensheathing cell tumor: a case report.  J Neurooncol. 2006;  76 111-113
  • 19 Adachi K, Yoshida K, Miwa T, Ikeda E, Kawase T. Olfactory schwannoma.  Acta Neurochir (Wien). 2007;  149 605-610 discussion 610-611
  • 20 Santhosh K, Kesavadas C, Radhakrishnan V V, Thomas B, Kapilamoorthy T R, Gupta A K. Usefulness of T2*-weighted MR sequence for the diagnosis of subfrontal schwannoma.  J Neuroradiol. 2007;  34 330-333
  • 21 Bezircioğlu H, Sucu H K, Rezanko T, Minoğlu M. Nasal-subfrontal giant schwannoma.  Turk Neurosurg. 2008;  18 412-414
  • 22 Daglioglu E, Okay O, Dalgic A, Albayrak A L, Ergungor F. Cystic olfactory schwannoma of the anterior cranial base.  Br J Neurosurg. 2008;  22 697-699
  • 23 Kanaan H A, Gardner P A, Yeaney G et al.. Expanded endoscopic endonasal resection of an olfactory schwannoma.  J Neurosurg Pediatr. 2008;  2 261-265
  • 24 Choi Y S, Sung K S, Song Y J, Kim H D. Olfactory schwannoma-case report-.  J Korean Neurosurg Soc. 2009;  45 103-106
  • 25 Martínez-Soto L, Alfaro-Baca R, Torrecilla-Sardón M V, Fernández-Vallejo B, Ferreira-Muñóz R, De Diego T. A new case of “olfactory schwannoma”; presentation and literature review.  Neurocirugia (Astur). 2009;  20 294-297
  • 26 Mirone G, Natale M, Scuotto A, Rotondo M. Solitary olfactory groove schwannoma.  J Clin Neurosci. 2009;  16 454-456
  • 27 Redekop G, Elisevich K, Gilbert J. Fourth ventricular schwannoma. Case report.  J Neurosurg. 1990;  73 777-781
  • 28 Frim D M, Ogilvy C S, Vonsattal J P, Chapman P H. Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review.  Pediatr Neurosurg. 1992;  18 190-194
  • 29 Nelson E, Rennels M. Innervation of intracranial arteries.  Brain. 1970;  93 475-490
  • 30 Kim H J, Cho H J, Kim K S et al.. Results of salvage therapy after failure of initial treatment for advanced olfactory neuroblastoma.  J Craniomaxillofac Surg. 2008;  36 47-52
  • 31 Burke D P, Gabrielsen T O, Knake J E, Seeger J F, Oberman H A. Radiology of olfactory neuroblastoma.  Radiology. 1980;  137 367-372
  • 32 Ichikawa M, Nakazawa T, Nioka H, Matsuda M, Handa J. Olfactory neuroblastoma with intracranial extension. Report of two cases.  Neurol Med Chir (Tokyo). 1989;  29 902-907 [Japanese, with Eng abstract]
  • 33 Yu J, Koch C A, Patsalides A et al.. Ectopic Cushing's syndrome caused by an esthesioneuroblastoma.  Endocr Pract. 2004;  10 119-124
  • 34 Sakamoto H, Nakai Y, Matsuda M et al.. Positron emission tomographic imaging of acoustic neuromas.  Acta Otolaryngol Suppl. 2000;  542 18-21
  • 35 Mauro A, Sciolla R, Sicuro L, Ponzio R. Solitary neurinoma of the anterior cranial fossa: case report.  J Neurosurg Sci. 1983;  27 45-49
  • 36 Nagao S, Aoki T, Kondo S, Gi H. Subfrontal schwannoma: a case report.  No Shinkei Geka. 1991;  19 47-51 [Japanese, with English abstract]
  • 37 Bando K, Obayashi M, Tsuneharu F. A case of subfrontal schwannoma.  No Shinkei Geka. 1992;  20 1189-1194 [Japanese, with English abstract]
  • 38 Harada T, Kawauchi M, Watanabe M, Kyoshima K, Kobayashi S. Subfrontal schwannoma—case report.  Neurol Med Chir. 1992;  32 957-960
  • 39 Gatsher S, Love S, Coakham H B. Giant nasal schwannoma with intracranial extension.  J Neurosurg. 1998;  89 161
  • 40 Bezircioglu H, Sucu H K, Rezanko T, Minoglu M. Nasal-subfrontal giant schwannoma.  Turkish Neurosurg. 2008;  18 412-414

Hitoshi YamahataM.D. 

Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University

8-35-1 Sakuragaoka, Kagoshim-shi, Kagoshima 890-8520, Japan

Email: yamahata-nsu@umin.net

Zoom Image

Figure 1 (A) Axial T2-weighted magnetic resonance imaging (MRI) revealing a subfrontal heterogeneously hyperintense mass. (B) Sagittal MRI with gadolinium demonstrating an enhanced subfrontal mass with extension to the ethmoid sinus. (C) Coronal computed tomography showing erosion of the left cribriform plate.

Zoom Image

Figure 2 Digital subtraction angiogram with left internal carotid artery injection showing the hypertrophic ophthalmic artery feeding the subfrontal mass.

Zoom Image

Figure 3 (A) Methionine positron emission tomography (PET) imaging showing a moderate-attenuation lesion in the frontal lobe. (B) The tumor was not identified on fluorodeoxyglucose PET.

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Figure 4 Postoperative magnetic resonance imaging with gadolinium demonstrating total resection of the tumor and a small hemorrhagic scar at the tumor site.

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Figure 5 Histopathologic examination of the surgical specimen showed that the tumor consisted of alternating areas of compact, elongated cells (Antoni type A) and less cellularized areas (Antoni type B) (hematoxylin and eosin; A × 50, B × 100). On immunohistochemical staining, the tumor cells were positive for S-100 protein (C) (×100).