arachnoid cyst has been reported.14 Dorsal arachnoid cystalone is the most common erroneous radiological diagnosisin patients with idiopathic spinal cord herniation.15 Severalauthors have proposed the use of phase-contrast (PC) cineimaging for determination of the presence or absence of adorsal arachnoid cyst.16,17 They also indicated that thecoexistence of a compressive dorsal arachnoid cyst isexcluded when PC cine imaging demonstrates normalCSF flow dorsal to the spinal cord at the level of hernia-tion. Ferre et al. reported three cases of idiopathic spinalcord herniation diagnosed with 3D-FIESTA in combina-tion with PC cine sequences.17 They noted that this combi-nation of sequences is very sensitive in detecting associatedabnormalities such as arachnoid cysts. However, high-resolution 3D MRI is quite sensitive in delineating thinmembranous structures such Liliequist membranes,9 andmight be sufficient alone for confirming the absence ofarachnoid cyst. In the present case, PC imaging was notused, since 3D-FIESTA images revealed no membranestructures of an arachnoid cyst.

Previously reported results for surgical treatment ofidiopathic spinal cord herniation have generally beenencouraging.1–4,6,12 In the present case, surgery resolvedthe sensory disturbance, although motor function wasnot restored. Several surgical techniques to reduce hernia-tion and prevent recurrence have been described. Most ofthem have included closure of the dural defect with anautogenous graft,6 an artificial surgical membrane,2 ordirect suturing.4 In several cases,1,3,12 the inner layer ofthe duplicated dura mater was resected or the dural defectwas enlarged to prevent recurrent strangulation of thespinal cord. In the present case, we enlarged the duraldefect. Strangulation of the spinal cord was alleviated bythis method, although the anterior bend of the spinal cordwas not completely corrected. The chronic nature of thiscondition indicates that this bending resulted from cordatrophy.

References

1. Saito T, Anamizu Y, Nakamura K, et al. Case of idiopathic thoracicspinal cord herniation with a chronic history: a case report and reviewof the literature. J Orthop Sci 2004;9:94–8.

2. Tekkok IH. Spontaneous spinal cord herniation: case report andreview of the literature. Neurosurgery 2000;46:485–92.

3. Nakazawa H, Toyama Y, Satomi K, et al. Idiopathic spinal cordherniation. Spine 1993;18:2138–41.

4. Kumar R, Taha J, Greiner AL. Herniation of the spinal cord. J

Neurosurg 1995;82:131–6.5. Uchino A, Kato A, Momozaki N, et al. Spinal cord herniation:

report of two cases and review of the literature. Eur Radiol

1997;7:289–92.6. Ewald C, Kuhne D, Hassler WE. Progressive spontaneous herniation

of the thoracic spinal cord: Case report. Neurosurgery 2000;46:493–6.7. Nitz WR. Fast and ultrafast non-echo-planar MR imaging tech-

niques. Eur Radiol 2002;12:2866–82.8. Casselman JW, Kuhweide R, Ampe W, et al. Inner ear malformations

in patients with sensorineural hearing loss: detection with gradient-echo (3DFT-CISS) MRI. Neuroradiology 1996;38:278–306.

9. Fushimi Y, Miki Y, Ueba T, et al. Liliequist membrane: three-dimensional constructive interference in steady state MR imaging.Radiology 2003;229:360–5.

10. Hirai T, Korogi Y, Shigematsu Y, et al. Evaluation of syringomyeliawith three-dimensional constructive interference in a steady state(CISS) sequence. J Magn Reson Imaging 2000;11:120–6.

11. Baskaran V, Pereles FS, Russell EJ, et al. Myelographic MR imagingof the cervical spine with 3D true fast imaging with steady-stateprecession technique: initial experience. Radiology 2003;227:585–92.

12. Hausmann ON, Moseley IF. Idiopathic dural herniation of thethoracic spinal cord. Neuroradiology 1996;38:503–10.

13. Russell E. Cervical disk diseases. Radiology 1990;177:313–25.14. Isu T, Iizuka T, Iwasaki Y, et al. Spinal cord herniation associated

with an intradural spinal arachnoid cyst diagnosed by magneticresonance imaging. Neurosurgery 1991;29:137–9.

15. Sioutos P, Arbit E, Tsairis P, et al. Spontaneous thoracic spinal cordherniation. A case report. Spine 1996;21:1710–3.

16. Brugieres P, Malapert D, Adle-Biassette H, et al. Idiopathic spinalcord herniation: value of MR phase-contrast imaging. AJNR Am J

Neuroradiol 1999;20:935–9.17. Ferre JC, Carsin-Nicol B, Hamalt A, et al. MR imaging features of

idiopathic thoracic spinal cord herniations using combined 3D-FIESTA and 2D-PC cine techniques. J Neuroradiol 2005;32:125–30.

doi:10.1016/j.jocn.2006.10.024

* CorE-m

Case Reports / Journal of Clinical Neuroscience 15 (2008) 937–939 937

Malignant paraganglioma of the sellar region mimicking apituitary macroadenoma

Sumit Sinha a,*, M.C. Sharma b, B.S. Sharma a

a Department of Neurosurgery, Neurosciences Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, Indiab Department of Neuropathology, Neurosciences Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India

Received 26 December 2006; accepted 21 March 2007

responding author. Tel.: +91 011 26593367.ail address: sumitaiims@yahoo.com (S. Sinha).

Abstract

We report a case of malignant sellar and suprasellar paraganglioma presenting as pituitary macroadenoma, causing headache andvisual deficits. The characteristics of this tumor at this rare location are discussed.� 2007 Elsevier Ltd. All rights reserved.

Keywords: Paraganglioma; Malignant; Pituitary adenoma

1. Introduction

938 Case Reports / Journal of Clinical Neuroscience 15 (2008) 937–939

Paragangliomas are rare benign tumors of neural crestorigin.1 They are rare in the sellar region, where no para-ganglionic tissue exists normally.1,2

2. Case report

An 18-year-old male presented with headache and visualdeterioration of 2 months’ duration. His hormone profilewas normal.

A plain X-ray of the skull showed an enlarged sella.MRI revealed a sellar suprasellar mass, which was isoin-tense on T1-weighted and hypointense on T2-weightedimages, with contrast enhancement (Fig. 1) and did not

Fig. 1. T1-weighted sagittal MRI showing a lesion with multiple flowvoids, with a branching pattern.

Fig. 2. Photomicrograph of the tumor tissue showing the Zellballenpattern (hematoxylin and eosin; �200).

involve the paranasal sinuses. Trans-sphenoidal subtotaldecompression was performed.

Light microscopic examination of the mass revealed anorderly arrangement of cell clusters near blood vessels(Fig. 2), distinct cellular outlines, abundant cytoplasm,occasional mitosis without vascular invasion and immuno-reactivity to chromogranin, synaptophysin and neuron-specific enolase. Ultrastructurally, polygonal cells withindented nuclei and sparse neurosecretory granules werepresent.

The patient was advised to undergo radiotherapy, buthe did not do so. The patient presented 4 months laterwith scalp swelling, excisional biopsy of which revealedmetastatic paraganglioma. A CT scan of the abdomenwas normal. A whole body bone scan showed hot spotsin the skull and right femur. An iodine-131 metaiodoben-zylguanidine (131I-MIBG) scan was normal. Gadolinium-enhanced MRI of the brain revealed a residual tumor inthe sella, which was confirmed by single photon emissionCT. The patient was receiving radiotherapy at the time ofwriting.

3. Discussion

The first reported sellar suprasellar paragangliomaswere described by Bilbao et al. in 19783. Since then only12 further cases have been reported,1,2 none of which havebeen malignant.

Paragangliomas originate from neural crest progenitorcells. Adrenal paragangliomas (pheochromocytomas) aremost common. Extra-adrenal paragangliomas are commonin the carotid artery (51.9%), tympanico-jugular region(36.6%), vagus, thorax and larynx. They rarely occur inthe inferior paraganglion nodosum, nose, paranasalsinuses, orbit, para-aortic space, lung or heart.4

Paragangliomas have also been reported in regions thatdo not normally contain paraganglion cells, including thesella, pineal gland, cavernous sinus, thyroid, cauda equinaand soft palate.3

The clinical features of these tumors arise from masseffects. The classic triad of symptoms (hypertension, dia-phoresis and palpitations) is typical of pheochromocyto-mas but less common in paragangliomas and rare inmalignant paragangliomas. Due to the extreme rarity ofparagangliomas, it is not realistic to include them in thedifferential diagnosis of sellar suprasellar tumors. Their

References

Case Reports / Journal of Clinical Neuroscience 15 (2008) 939–942 939

clinical features, neuroimaging findings and behaviormimic pituitary adenoma and sellar meningiomas; hence,diagnosis is usually made postoperatively. Paragangliomasare firm, encapsulated tumors with rich vascularity. Vas-cular flow voids and intense enhancement on MRI differ-entiates them from pituitary adenomas.5 Single photonemission computed tomography (SPECT) is helpful in dif-ferentiating paraganglioma and pituitary adenoma.6 Diag-nosis is confirmed by postoperative immunohistochemicalanalysis.4 Other highly vascular lesions that can be con-fused with these tumors are choristomas and vascularmetastases.

It has been suggested that paraganglionic tissue mightbecome trapped in/around the pituitary gland, whichmay develop into sellar suprasellar paraganglioma.2,6

Abnormal migration of paraganglionic cells from the tym-panic branch of the glassopharyngeal or ciliary nerves andpetrous bone during the fetal/neonatal period is a sug-gested alternative mechanism.1

Histologically, paragangliomas may show the classic‘‘Zellballen” pattern charcterized by cords of chief cellssurrounded by sustentacular cells. A paucity or absenceof sustentacular cells may indicate aggressive or malig-nant behavior.7 In our patient, no such cells were seenon light microscopy or on immunohistochemical stain-ing with S100 protein. There are no reliable criteriafor diagnosis of malignancy except local recurrence ordistant metastasis, although loss of organoid pattern,central necrosis of Zellballen, nuclear pleomorphismand decreased expression of neuropeptides have beenproposed.6,8

The optimal treatment for paragangliomas is yet to beestablished. Complete excision is the treatment of choicefor benign and malignant paragangliomas, but in somecircumstances it may not be technically feasible due tohard consistency, rich vascularity and involvement ofthe cavernous sinus, optic chiasma and carotid arteries.Postoperative radiotherapy is recommended for subse-

doi:10.1016/j.jocn.2007.03.029

Kimiaki Hashiguchi *, Takato Morioka, KazuFumiaki Yoshida, Shinj

Department of Neurosurgery, Graduate School of Medical Sciences, Ky

Received 21 December 2006

* Corresponding author. Tel.: +81 92 642 5524; fax: +81 92 642 5526.E-mail address: khash@med.kyushu-u.ac.jp (K. Hashiguchi).

quent tumor growth after maximal tumor resection orin malignant paragangliomas with distant metastases.4131I-MIBG has been used for reducing tumor size anddecreasing bone metastases.9 The role of chemotherapyis controversial.10

In conclusion, paragangliomas are benign tumors thatrarely metastasize. This is the first reported case of malig-nant sellar suprasellar paraganglioma with multiple metas-tases. Preoperative diagnosis is difficult as these lesionsmimic pituitary adenoma and sellar meningioma, so diag-nosis can only be made postoperatively based on histopa-thological and immunohistochemical data.

hi

us

;

1. Hertel F, Bettag M, Morsdorf M, et al. Paragangliomas of parasellarregion. Neurosurg Rev 2003;26:210–4.

2. Naggara O, Varlet P, Page P, et al. Suprasellar paraganglioma: casereport and review of literature. Neuroradiology 2005;47:753–7.

3. Bilbao JM, Horvath E, Kovacs K, et al. Intrasellar paragangliomaassociated with hypopituitarism. Arch Pathol Lab Med 1978;102:95–8.

4. Lack EE, Cubila AL, Woodruff JM. Paragangliomas of head andneck region: A pathologic study of tumors from 71 patients. Hum

Pathol 1979;10:191–218.5. Flint EW, Claassen D, Pang D, et al. Intrasellar and parasellar

paraganglioma: CT and MR findings. AJNR Am J Neuroradiol

1993;14:1191–3.6. Salame K, Ouaknine GER, Yossipov J, et al. Paraganglioma of the

pituitary fossa: diagnosis and management. J Neurooncol 2001;54:49–52.

7. Lloyd RV, Blaivas M, Wilson BS. Distribution of chromogranin andS-100 protein in normal and abnormal medullary tissues. Arch Pathol

Lab Med 1985;109:633–5.8. Linnoila RI, Lack EE, Steinberg SM, et al. Decreased expression of

neuropeptides in malignant paragangliomas. An immunohistochem-ical study. Hum Pathol 1998;19:41–50.

9. Baulieu JL, Guilloteau D, Baulieu F, et al. Therapeutic effectiveness ofiodine-131 MIBG in metastases of a nonsecreting paraganglioma. J

Nucl Med 1988;29:2008–13.10. Kimura S, Iwai M, Fukuda T, et al. Combination chemotherapy for

malignant paraganglioma. Intern Med 1997;36:35–9.

Medial temporal lobe epilepsy associated with misplacement ofa ventricular shunting catheter

iro Samura, Yasushi Miyagi,Nagata, Tomio Sasaki

hu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

accepted 19 February 2007