Figure 2. A, Follow up angiogram, anteroposterior projection, showing a denovo aneurysm arising at the carotid bifurcation (arrow). The previouslytreated middle cerebral artery aneurysm shows no sign of recanalization;B, Postembolization aspect, showing the microcoil casts and completeocclusion of both aneurysms.

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by most authors (1-3, 5), particularly in young patients with riskfactors such as arterial hypertension (4), smoking (1, 4), multipleand familial aneurysms (2), and congenital connective tissue dis-orders (3). Magnetic resonance angiography and three-dimensionalcomputed tomographic angiography can be used as a goodscreening tool for de novo aneurysms.

Eduardo Wajnberg

From the Radiology Department, University of Brazil, Rio de Janeiro, BrazilTo whom correspondence should be addressed: Eduardo Wajnberg, M.D.[E-mail: eduardowj@gmail.com]

Published online 1 November 2011; http://dx.doi.org/10.1016/j.wneu.2011.01.016.

REFERENCES

1. Juvela S, Poussa K, Porras M: Factors affecting formation and growth of intra-cranial aneurysms: A long term follow-up study. Stroke 32:485-491, 2001.

2. Motuo Fotso MJ, Brunon J, Outhel R, Fischer G: [Familial aneurysms, multipleaneurysms and “de novo” aneurysms: Apropos of 2 cases]. Neurochirurgie 39:225-230, 1993 [in French].

3. Nakamura M, Rosahl SK, Vorkapic P, Forster C, Samii M: De novo formation of ananeurysm in a case of unusual intracranial fibromuscular dysplasia. Clin NeurolNeurosurg 102:259-264, 2000.

4. Tonn J, Hoffmann O, Hofmann E, Schlake HP, Sorensen N, Roosen K: “De novo”formationof intracranial aneurysms:who is at risk?Neuroradiology41:674-679, 1999.

5. Yoneoka Y, Takeda N, Akira I, Ibuchi Y, Kumagai T, Sugai T, Takeda K-I, Ueda K:Ruptured denovo intracranial aneurysms. ActaNeurochir (Wien) 146:979-981, 2004.

IN REPLY:

Wajnberg reports a well-documented case of a de novo aneu-rysm in a 53-year-old woman who was initially treated

through endovascular coiling of a ruptured left middle cerebralartery aneurysm. Six months later, in a follow-up angiography,they discovered a new (de novo) aneurysm in the left internalcarotid artery bifurcation.

The most important message of this case report is to confirm thenecessity of periodic follow-ups after aneurysm treatment, initiallyto confirm complete exclusion of the lesion, and later on toidentify not only incomplete clipping/coiling or recurrence of thepreviously treated aneurysm, but also to identify de novo

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aneurysms. The follow-up is ideally done with computerizedtomographic angiography or magnetic resonance angiography,using digital angiography only in cases where those noninvasiveexaminations are not good enough to ensure that there are neitherrecurrences nor de novo aneurysms.

As stressed by the literature and mentioned by the author, thefollow-up is particularly important in the group of patients withmajor risk factors, mainly young subjects, such as arterial hyper-tension, smoking, multiple and familial aneurysms, and congen-ital connective tissue disorders.

Atos Alves de Sousa

From the Faculdade de Ciencias Medicas de Minas Gerais, Santa Casa Hospital,Belo Horizonte, BrazilTo whom correspondence should be addressed: Atos Alves de Sousa, M.D., Ph.D.[E-mail: sousatos@hotmail.com; atosdesousa@atosdesousa.com]

http://dx.doi.org/10.1016/j.wneu.2010.02.074.

Ewing Sarcoma of the Occipital Bone in an Elderly Patient

LETTER:

Ewing sarcoma is a primary bone tumor commonly occurring inthe first two decades of life, usually as a solitary lesion in the

long bones, ribs, and flat bones such as the pelvis (6). Primarycranial Ewing sarcoma occurs in 1% to 6% of all cases of Ewingsarcoma (1, 6). We would like to highlight a case with occurrenceof this disease in occipital region at an unusually older age withintratumoral bleed.

A 52-year-old male presented with low-grade fever for 1 monthwith progressively worsening holocranial headache and diminu-tion of vision for 3 days and ataxia. He had bilateral optic atrophy.Local examination revealed a bony swelling at the back of head.Computed tomography head revealed a posterior fossa space-occupying lesion with obstructive hydrocephalous. Bone wasexpanded with rarefaction (Figure 1A). An emergency ven-triculoperitoneal shunt was performed. A heterogeneous masslesion of occipital bone was seen on magnetic resonance (MR)imaging with intracranial extension, both supra and infratento-rially pushing the sinuses anteriorly and eroding the dura infra-tentorially (Figure 1B). Heterogeneous enhancement was seen oncontrast. There was MR signal in the anterior part of the lesionsuggestive of bleed. Right transverse sinus and medial one third ofleft transverse sinus was thrombosed on MR venography. Meta-static workup, including bone, scan was negative.

A preoperative diagnosis of metastatic lesion with occult primarywas made, and the patient underwent surgery via a midline sub-occipital craniotomy and occipital craniotomy. The peritorcularsite of surgery made the surgical excision a technical challenge.Bone was found to be thick and spongy at places with involvementin of both inner and outer tables. The lesion was grayish red,vascular, eroding the dura, and projecting into the vermis. He-matoma was present in the anterior part of the tumor (Figure 1B).Near-total excision of the tumor was achieved both supra andinfratentorially. Histopathology report revealed a small round celltumor. It stained positive for CD99 and vimentin. Patient was

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Figure 1. A, Computed tomography bone window showing expansion with rarefaction of the occipital bone. B, Contrastsagittal MR image showing mass from the occipital bone extending into both supra and infratentorially, pushing the sinusesand torcula anteriorly. The lesion was eroding the posterior fossa dura into cerebellar parenchyma with bleed anteriorly. Thefourth ventricle is compressed.

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given two cycles of vincristine, adriamycin, and cyclophosphamidealternating with etoposamide and ifosfamide every 3 weeks, fol-lowed by 50 grays of radiation to the local site. Maintenancechemotherapy was given by the use of the same drugs for 4months. Six months later he came back with local recurrence.A bone scan ruled out metastatic lesion. He died within 2 weeks ofpresentation.

Primary Ewing sarcoma of the cranial bone is uncommon and itusually involves the frontal and the parietal bone. It predominantlyaffects children and young adults, with a peak incidence in therange of 5-13 years (2). The occurrence of disease in patients olderthan 40 years of age has not been reported. Occipital boneinvolvement has been reported on few occasions previously, but allof the patients were in the usual young age group (2, 3, 6). Also, agood outcome has been reported after radical surgery andchemoradiation.

Headache remains the most common presenting complaint, and itis commonly associated with papilloedema on examination.Worsening of headache in our case was probably because of thetumor bleed with obstructive hydrocephalus. The characteristiconion peel appearance on plain radiographs is often absent.Distant metastasis is rare unlike Ewing sarcoma at other sites.Also, the prognosis of primary cranial Ewing sarcoma is betterthan that at other sites (1, 6). Computed tomography scan revealsextensive destruction of both inner and outer tables with osteo-blastic activity. Histological features of round cell tumorscompactly arranged in sheets with scanty cytoplasm and promi-nent nuclei and no rosette formation or features of mitosis. Stainsfor CD99 and vimentin are positive.

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It is generally accepted that the treatment consists of systemicchemotherapy with radical excision of tumor and radiotherapy forlocal control (4). Local recurrence of Ewing sarcoma in generalcarries a poorer prognosis especially if it occurs within 2 years (5).Neoadjuvant chemotherapy to reduce the tumor size may not bepossible in cranial Ewing sarcoma as the result of increasedintracranial pressure that makes surgical decompression neces-sary. Although, cranial Ewing sarcoma has a better prognosis thanthat at other sites, early recurrence and old age may not beassociated with a good outcome.

Pravin Salunke1, Manish Sharma1 Kirti Gupta2

From the Departments of 1Neurosurgery and 2Histopathology, PGIMER,Chandigarh, IndiaTo whom correspondence should be addressed: Pravin Salunke, M.Ch.[E-mail: drpravin_salunke@yahoo.co.uk]

http://dx.doi.org/10.1016/j.wneu.2010.12.050.

REFERENCES

1. Desai KI, Nadkarni TD, Goel A, Muzumdar DP, Naresh KN, Nair CN: PrimaryEwing’s sarcoma of the cranium (review). Neurosurgery 46:62-68, 2000; discus-sion 68-9.

2. Erol FS, Ozveren MF, Ozercan IH, Topsakal C, Akdemir I: Primary Ewing’s sar-coma of the occipital bone—case report. Neurol Med Chir (Tokyo) 41:206-209,2001.

3. Garg A, Ahmad FU, Suri A, Mahapatra AK, Mehta VS, Atri S, Sharma MC, Garg A:Primary Ewing’s sarcoma of the occipital bone presenting as hydrocephalus andblindness. Pediatr Neurosurg 43:170-173, 2007.

4. Grier HE, Krailo MD, Tarbell NJ, Link MP, Fryer CJ, Pritchard DJ, Gebhardt MC,Dickman PS, Perlman EJ, Meyers PA, Donaldson SS, Moore S, Rausen AR,

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CORRESPONDENCE

Vietti TJ, Miser JS: Addition of ifosfamide and etoposide to standard chemo-therapy for Ewing’s sarcoma and primitive neuroectodermal tumor of bone.N Engl J Med 348:694-701, 2003.

5. Leavey PJ, Mascarenhas L, Marina N, Chen Z, Krailo M, Miser J, Brown K,Tarbell N, Bernstein ML, Granowetter L, Gebhardt M, Grier HE: Prognostic fac-tors for patients with Ewing sarcoma (EWS) at first recurrence following multi-

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modality therapy: a report from the Children’s Oncology Group. Pediatr BloodCancer 51:334-338, 2008.

6. Yasuda T, Inagaki T, Yamanouchi Y, Kawamoto K, Kohdera U, Kawasaki H,Nakano T: A case of primary Ewing’s sarcoma of the occipital bone presentingwith obstructive hydrocephalus. Childs Nerv Syst 19:792-799, 2003.

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