an unusually aggressive clinical behavior in a case of atypical subependymal giant cell astrocytoma

have divided the plasmacytoma of the skull base into anterior nasopharyngeal group and central sphenoid, clivus, petrous apex group.. Moreover plasmacytomas are also classified as extram

another six more cases since then.[1-6] Wein et al have

divided the plasmacytoma of the skull base into

anterior (nasopharyngeal) group and central (sphenoid,

clivus, petrous apex) group This is of prognostic

importance because in the central group, the rate of

progression to multiple myeloma is 63.6%, which is much

higher than that in the anterior group (9.5%) Moreover

plasmacytomas are also classified as extramedullary

plasmacytoma (EMP) or solitary plasmacytoma of

bone (SPB).[1] Most of the anterior group of skull base

plasmacytoma fall into EMP group and the central

skull base plasmacytoma fall into SPB group Since

solitary plasmacytoma represents only one end of the

spectrum of plasma cell tumors and represents a distinct

manifestation of a disease continuum, progression to

multiple myeloma is almost invariable Hence adjuvant

therapy is essential to arrest further progression of the

disease

This patient had involvement of frontal and ethmoidal

sinuses and eroding the floor of the anterior cranial fossa

and most probably falls into the group of EMP Hence,

though the tumor had been excised totally adjuvant

radiotherapy was given to the patient The possibility of

plasmacytoma has to be kept in mind in any osteolytic

tumor of the skull base

Acknowledgement

We thank Prof K Ramesh Rao, Department of Pathology,

Chettinad Superspeciality Hospital, Chennai, for providing

the histopathology pictures.

Ramesh Ganesan Vengalathur, Karthikeyan Veerasamy Kavindapadi, Balasubramanian Chandramouli

Department of Neurosurgery, Chettinad Superspeciality Hospital,

Chettinad Health City, Kelambakkam, Chennai, Tamil Nadu, India

E‑mail: drvgramesh@hotmail.com

References

1 Wein RO, Popat SR, Doerr TD, Dutcher PO Plasma cell tumors of the skull

base: Four case reports and literature review Skull Base 2002;12:77-86.

2 Ustuner Z, Basaran M, Kiris T, Bilgic B, Sencer S, Sakar B, et al Skull

base plasmacytoma in a patient with light chain myeloma Skull Base

2003;13:167-71.

3 Singh AD, Chacko AG, Chacko G, Rajshekhar V Plasma cell tumors

of the skull Surg Neurol 2005;64:434-8.

4 Pancholi A, Raniga S, Vohra PA, Vaidya V, Prajapati A, Mansingani S

Imaging features of extramedullary plasmacytoma of skull base

with multiple myeloma—A rare case Indian J Radiol Imaging

2006;16:29-32.

5 Yamaguchi S, Terasaka S, Ando S, Shinohara T, Iwasaki Y Neoadjuvant

therapy in a patient with clival plasmacytoma associated with multiple

myeloma: A case report Surg Neurol 2008;70:403-7.

6 Guinto-Balanzar G, Abdo-Toro M, Aréchiga-Ramos N, Leal-Ortega R,

Zepeda-Fernández E, Nambo-Lucio Mde J Plasma cell tumor of the

clivus: Report of two cases Cir Cir 2012;80:171-6.

Access this article online Quick Response Code: Website:

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PMID:

***

DOI:

10.4103/0028-3886.144457

Received: 16-07-2014 Review completed: 26-08-2014 Accepted: 03-10-2014

An unusually aggressive clinical behavior in a case of atypical subependymal giant cell astrocytoma

Sir, Subependymal giant cell astrocytoma (SEGA) is a benign tumor that mostly arises in the wall of the lateral ventricle.[1] Though it has been classified as a low grade, WHO Grade 1 tumor, aggressive lesions with metastasis and intratumoral hemorrhages have been described.[2,3]

High grade features like mitoses, focal necrosis, and endothelial proliferations are distinctly rare, but few cases have been reported in the literature with these unusual findings of high-grade tumor, termed as atypical SEGA.[4,5] Despite anaplasia in histology, the clinical behavior of these patients have been benign, same as typical SEGA A few cases of atypical SEGA may behave aggressively.[5] We report a case of atypical SEGA mimicking malignant glioma with an unusually aggressive clinical course

A 5-year-old male child presented with 1 month history

of worsening headache with right hemiparesis and facial weakness Magnetic resonance imaging (MRI) showed a large lesion in the left posterior thalamic region abutting the atrial wall with peripheral enhancement with edema [Figure 1a and b] There were no markers of tuberous sclerosis complex (TSC) The patient underwent

a parietooccipital craniotomy and near total resection

of the tumor through transcortical, transventricular route [Figure 1c and d] Immediate postoperative period was uneventful The histology showed spindle-shaped

to large polygonal tumor cells with many multinucleated giant cells scattered in between [Figure 2] Large necrotic areas were observed Few mitotic figures were identified with Ki-67 labelling index around 2-3% The tumor also showed glial fibrillary acidic protein (GFAP) positivity

The overall features were suggestive of SEGA with atypical features Within 3 weeks of primary surgery, the patient presented with altered sensorium and progressively worsening right hemiparesis MRI showed a small

recurrent lesion with hydrocephalus Ventriculoperitoneal

shunt was placed following which the sensorium

improved In view of the early recurrence and high-grade

histological features, conformal radiotherapy was given

A month later, the clinical condition worsened and repeat

imaging showed increase in size of lesion with invasion of

adjacent structures [Figure 1e and f] Because of the poor

general condition, reexcision of tumor could not be offered

and the patient subsequently died within a fortnight

SEGAs are low-grade tumors that seem to arise from the

ependymal layer lining the ventricular walls They usually

arise near the foramen of Monro, though other ventricular

Figure 1: (a and b) Preoperative MRI showing large heterogeneous left thalamic lesion with peripheral contrast enhancement (c and d) Postoperative

CT showing near total excision of the tumor (e and f) Plain CT and contrast-enhanced MRI at 4 months showing large recurrence

MRI = Magnetic resonance imaging, CT = computed tomography

d

c b

f

a

e

Figure 2: (a) Low power photomicrograph showing a cellular tumor

with large areas of necrosis (H and E, ×4), (b) The tumor is composed

of bizarre, multinucleated cells in a fibrillary background (H and E, ×20)

(c) Tumor cells show strong GFAP expression (IP, ×20) (d) Ki-67

immunostain showing high proliferative index in tumor cells (IP, ×40)

H and E = Hematoxylin and Eosin, IP = Immunoperoxidase

d c

b a

locations have been described It has been linked with TSC, though occasionally, they can occur sporadically.[1] It most frequently occurs in the first 2 decades of life Owing

to its periventricluar location they frequently obstruct the ventricular pathway producing symptoms of raised pressure with other clinical manifestations being seizure, mental retardation, cognitive disability, and visual disturbances Computed tomography (CT) shows uniformly dense lesion with occasional peripheral calcifications These are commonly homogenous lesions with occasional cystic changes that appear isohypointese on T1-weighted (T1W) and hyperintense on T2W images with marked contrast enhancement Histologically it is composed of three types

of cells: Swollen gemistocytic cells, fibrillated spindle cells, and giant ganglion-like cells.[1] There are large polygonal cells with abundant cytoplasm arranged in sheets, clusters,

or pseudorosettes with different degrees of vascularization, angiocentric pattern, and calcifications Few cases may show anaplastic features like nuclear pleomorphism, mitosis, necrosis, microvascular proliferation, and increased Ki-67 index; but traditionally these high-grade features have been said not to impact the diagnosis or prognosis.[4]

These high-grade histologic features may easily lead to misdiagnosis of glioblastoma Absence of atypical small cells, low mitotic count, and Ki 67 index as compared

to glioblastoma have been suggested to be the best discriminative features.[4] In spite of presence of necrosis and mitosis, the biological behavior of these atypical tumors

is not aggressive and does not mandate radiotherapy and chemotherapy However, cases of atypical SEGA have been described in young children with a more rapid growth pattern due to malignant change and hemorrhage.[4,5]

In our case the tumor recurred very rapidly and

the clinical course was almost similar to malignant

tumors In contrast to the traditional belief, our patient

showed concordance between high-grade histological

features and the clinical outcome So it is difficult to

prognosticate these atypical SEGAs and the clinical

course may vary in different cases Utmost caution

should be exercised in managing these patients Those

with aggressive course should probably be treated as

other malignant gliomas

Devi Prasad Patra, Pravin Salunke, Debajyoti Chatterjee 1 , R K Vasishta 1

Departments of Neurosurgery, and 1 Histopathology, Post Graduate

Institute of Medical Education and Research, Chandigarh, India

E‑mail: drpravin_salunke@yahoo.co.uk

References

1 Ouyang T, Zhang N, Benjamin T, Wang L, Jiao J, Zhao Y, et al

Subependymal giant cell astrocytoma: Current concepts, management,

and future directions Childs Nerv Syst 2014;30:561-70.

2 Telfeian AE, Judkins A, Younkin D, Pollock AN, Crino P Subependymal

giant cell astrocytoma with cranial and spinal metastases in a patient

with tuberous sclerosis Case report J Neurosurg 2004;100 (5 Suppl

Pediatrics):498-500.

3 Ogiwara H, Morota N Subependymal giant cell astrocytoma with

intratumoral hemorrhage J Neurosurg Pediatr 2013;11:469-72.

4 Svajdler M Jr, Deák L, Rychlý B, Talarčík P, Fröhlichová L

Subependymal giant cell astrocytoma with atypical clinical and

pathological features: A diagnostic pitfall Cesk Patol 2013;49:76-9.

5 Grajkowska W, Kotulska K, Jurkiewicz E, Roszkowski M, Daszkiewicz P,

Jóźwiak S, et al Subependymal giant cell astrocytomas with atypical

histological features mimicking malignant gliomas Folia Neuropathol

2011;49:39-46.

Access this article online Quick Response Code: Website:

www.neurologyindia.com

PMID:

***

DOI:

10.4103/0028-3886.144458

Received: 13-10-2014 Review completed: 14-10-2014 Accepted: 15-10-2014

nerves Schwannomas arising from the oculomotor nerve are very rare, except with neurofibromatosis

Approximately 40 cases of oculomotor nerve schwannomas have been described in the literature, of which 12 cases were large (≥2.5cm)[1,2] tumors This report presents a case

of giant oculomotor nerve schwannoma

A 24-year-old female complained of progressive diplopia, ptosis of left eye for 2 years These complaints were overlooked by family members For the last six months, she had developed gradual progressive visual loss of left eye followed by right eye She also used

to have generalized headache, vomiting and features suggesting hypo-function of pituitary gland On examination, her visual acuity was figure counting at

1 meter distance in both the eyes with left oculomotor nerve palsy and bilateral optic atrophy Magnetic resonance imaging (MRI) of brain revealed a large,

enhancing mass (6.1 × 3.6 × 6.2 cm) with central necrosis

involving sellar and suprasellar regions, extending into left middle cranial fossa [Figures 1 and 2] Left pterional craniotomy and wide splitting of the Sylvian fissure for tumor access was carried out A large encapsulated, white, firm, moderately vascular, multilobulated tumor was found with a necrotic yellowish central zone Intratumoural decompression, followed by dissection of tumor in arachnoid plane carried out

Though the tumor was abutting internal carotid artery

Giant oculomotor nerve

schwannoma presenting as a

sellar and suprasellar mass

with parasellar extension

Sir,

Schwannomas account for 7% of all intracranial tumors and

commonly arise from the vestibulocochlear and trigeminal

Figure 1: An axial T1- and T2-weighted MRI scan showing (T1-hypointense and T2-hyperintense) sellar mass with left parasellar extension

Figure 2: Coronal and sagittal gadolinium-enhanced contrast T1-weighted MRI scan showing the said enhancing mass with central area

of hypointensity The lesion was compressing the optic chiasma with

ipsilateral carotid encasement

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