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British Journal of Neurosurgery, April 2012; 26(2): 278–280

© 2012 The Neurosurgical Foundation

ISSN: 0268-8697 print / ISSN 1360-046X online

DOI: 10.3109/02688697.2011.603855

Intramedullary metastasis in a case of vermian medulloblastoma

Venkatesh S. Madhugiri 1 , Paritosh Pandey 2 , B. Indira Devi 2 , Vani Santosh 3 & T. C. Yasha 3

1 Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India ,

2 Department of Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India ,

3 Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India

Correspondence: Paritosh Pandey, Department of Neurosurgery, NIMHANS, Hosur Road, Bangalore 560029, India. Tel: � 91 8026995402.

Fax: � 91 8051282284. E-mail: paritosh2000@gmail.com

Received for publication 24 March 2011; accepted 4 July 2011

seizures. He complained of increased frequency of micturi-

tion for 1 month. CNS examination revealed bilateral papil-

loedema and VI nerve paresis. Tone was increased in both

lower limbs, with grade 4/5 power. He had sensory loss to all

modalities over a stocking distribution.

Radiology Over a period of 6 months, the patient was investigated with

three MRI scans. Th e fi rst scan (Fig. 1a) revealed a small

inferior vermian nodule projecting into the IV ventricle. Th e

lesion was isointense on T1- and T2-weighted images and

did not enhance with contrast administration. Similar lesions

were present in both cerebellopontine angle cisterns. On

the second MRI (Fig. 1b) (2 months later), fresh lesions had

appeared in the prepontine cistern and in the region of the

cavernous sinus. Th ese and all other lesions were Gd-DTPA

contrast enhancing. Th ere was also diff use leptomeningeal

enhancement. Th e third MRI (at current admission) showed

similar fi ndings. In addition, there were intramedullary

lesions at C6-D2 (Fig. 1c) and at D5-6 (Fig. 1d).

Several lumbar punctures for CSF analysis were carried

out. CSF protein levels were consistently elevated. CSF

cytology was negative on the fi rst four lumbar CSF samples.

Th e fi nal CSF sample was positive for malignant cells, sug-

gestive of medulloblastoma.

Treatment Th e tumor stage was T1 M3 (modifi ed Chang ’ s). Adjuvant

therapy, including craniospinal radiotherapy and chemo-

therapy, was initiated. Two months later, the patient pre-

sented with two episodes of generalized seizures, which

were controlled with medication. Th ere was no change in his

neurological status. He was subsequently lost to follow-up.

Discussion

Medulloblastoma is a common childhood tumor. Staging

the disease has important prognostic implications. Dissemi-

nated disease at presentation (including leptomeningeal

SHORT REPORT

Abstract

Medulloblastoma is one of the commonest primary CNS

malignancies in children. Leptomeningeal dissemination and

distant metastasis have been associated with medulloblastoma,

but intramedullary metastases are very rare. CSF cytology

and contrast-enhanced MRI are the main modalities used

to diagnose leptomeningeal dissemination. However,

intramedullary metastases are best picked up with contrast-

enhanced axial sequences on MR imaging. In this report, a

patient with medulloblastoma who developed intramedullary

metastasis is described. The role of imaging and CSF

cytology in diagnosing the spread along the CSF pathways is

reviewed. Allusions are made to the possible mechanism of

intramedullary metastasis in these tumors.

Keywords: CSF cytology ; intramedullary ; leptomeningeal

dissemination ; medulloblastoma ; metastasis ; MRI.

Introduction

Medulloblastoma is a common CNS tumor in children. It

frequently spreads along the CSF pathways. ‘ Spinal spread ’

takes the form of either leptomeningeal dissemination

(LMD) or lesions in the conus-cauda region. Intramedullary

metastases are very rare and only a few case reports are avail-

able in the literature. In this report, a patient who developed

intramedullary metastasis from a vermian medulloblastoma

is described. Th e spinal metastasis was diagnosed on the

basis of radiology and CSF cytology. Various issues germane

to the diagnosis and pathology in such cases are reviewed.

Clinical details

A 19-year-old teenager presented with progressively wors-

ening holocranial headache associated with vomiting since

8 months. Since 4 months, he had developed progressive

spasticity and weakness of both lower limbs, associated

with sensory loss over the ankles and feet. Th ree months

previously, he had four episodes of generalized tonic-clonic

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Intramedullary metastasis in medulloblastoma 279

involvement) connotes a worse prognosis and is there-

fore important to detect. Forty percent of all patients with

medulloblastoma may develop drop metastasis to the spinal

leptomeninges and 52.6% may have localized leptomenin-

geal involvement.

Th e patient described in this report had disseminated

intracranial disease on the fi rst MRI (Fig. 1a,b). Th e second

MRI showed extensive LMD but CSF cytology was negative

for malignant cells at this time. Th e only signifi cant fi nding

was a consistently elevated CSF protein level. Th e fi nal avail-

able CSF analysis was positive for malignant cells, by which

time the MRI showed not only diff use craniospinal LMD, but

also intramedullary metastasis. It is also important to note

that the CSF proteins were grossly and persistently elevated

in this patient, even before the MRI showed any evidence of

LMD. Th is could be an important fi nding and it is desirable

to obtain CSF for analysis prior to operating on the tumor,

since surgery will alter the biochemical profi le of CSF.

Intramedullary metastasis in medulloblastoma is

extremely rare. A PubMed search using the keywords

‘ medulloblastoma ’ , ‘ metastasis ’ , ‘ intramedullary spread ’ ,

‘ intramedullary metastasis ’ , and ‘ spinal spread ’ in various

combinations revealed very few reports. Zumpano was

one of the fi rst authors to report a case with intramedul-

lary metastasis from a medulloblastoma. 1 Since then, spo-

radic reports have appeared in the literature. Some authors

have reported the presence of intramedullary metastasis

at presentation. 2 However, in most of the reported cases,

intramedullary deposits occurred late in disease or at the

time of disease recurrence after primary treatment. 3 In

this patient, intramedullary metastasis occurred late in the

course of the disease. Th e clinical features of lower limb

involvement appeared last and only the fi nal MRI revealed

the two intramedullary lesions.

Th e mechanism of intramedullary metastasis has not

been conclusively elucidated. Possible routes of spread

include CSF dissemination of cells, and arterial and venous

emboli. 1 LMD is not always present prior to the develop-

ment of an intramedullary lesion. 3 Th us, it would be logi-

cal to infer that the central canal (or blood) is the route of

dissemination in such cases. Zumpano postulated that

intramedullary spread occurred by direct extension from a

primary cerebellar medulloblastoma to an enlarged spinal

central canal due to accompanying hydrocephalus. Most

patients, however, do not have a patent obex; this theory

would not be tenable in such cases. If the central canal was

the route of dissemination, the tumor cells would have to

cross the ependymal barrier to enter the substance of the

cord. On the other hand, if the CSF pathways were the

route of dissemination, adhesion to the leptomeningeal

cells followed by invasion would be essential. Th is would

imply that medulloblastoma cells are able to adhere to and

invade ependymal cells and/or the leptomeninges and

neural tissue. Many adhesion molecules are expressed by

medulloblastoma cells. Th e polysialic neural cell adhesion

molecule (PS-NCAM) has been identifi ed and used as a

marker of invasion and prognosis. PSA-NCAM concentra-

tion medians were higher in the CSF with metastatic cells

or that corresponding to abnormal imaging than in the cor-

responding normal groups. Th e PSA-NCAM concentration

was signifi cantly higher in the CSF from patients refractory

to treatment or those who relapsed than from patients in

remission.

LMD is common with medulloblastoma. On MRI, LMD

may be seen as a diff use leptomeningeal enhancement.

Th e other pattern is that of multiple nodules studding

the pia or the cauda equina. Intramedullary metastases

are best detected on Gd-DTPA contrast-enhanced axial

T1 sections or on Gd-DTPA-enhanced CISS-3D axial

sequences. Lesions are seen within the substance of the

cord. Spinal screening protocols are limited to contrast

sagittal sequences in most instances. Any atypical clinical

feature suggestive of spinal cord involvement mandates a

more extensive spinal imaging. Clinical features and signs

may be variable since LMD and intramedullary lesions can

coexist. Axial sequences are absolutely essential to demon-

strate conclusively the presence of intramedullary lesions.

On sagittal sequences, nodules studding the pia on the

surface of the cord may sometimes appear to be within the

substance of the cord.

If intramedullary metastases were present, would such

tumors invariably express adhesion molecules? Do tumors

without intramedullary metastases also express adhesion

molecules? Th e signifi cance of such expression vis- à -vis

tumor spread and prognosis is yet to be determined. Th us,

several questions are raised with respect to medulloblastoma

biology.

Fig. 1. (a) T2 isointense vermian nodule with lesions in the bilateral cerebellopontine angle cisterns (fi rst MRI). (b) Gd-DTPA-enhanced MRI showing diff use leptomeningeal enhancement, bilateral parasellar lesions extending into the prepontine space, and the enhancing vermin nodule (second MRI). (c) T1 sagittal MRI showing the intramedullary lesion at C6-D2 (third MRI). (d) Gd-DTPA-enhanced axial MRI showing the faintly enhancing intramedullary lesion at D5-6 (third MRI).

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280 V. S. Madhugiri et al.

Conclusions

All patients with medulloblastoma should undergo con-

trast craniospinal MRI at diagnosis for staging the disease.

In patients with medulloblastoma who develop gait distur-

bances, cerebellar involvement or hydrocephalus are usu-

ally suspected as a cause. However, intramedullary lesions

should be borne in mind because these can be missed if

they are very small in size. Leptomeningeal disease need

not precede intramedullary lesions. Th e use of immunohis-

tochemistry for detecting adhesion molecules may help to

predict the occurrence of such lesions and the prognosis.

Declaration of interest : Th e authors report no confl icts of

interest. Th e authors alone are responsible for the content

and writing of the paper.

References

Zumpano BJ. Spinal intramedullary metastatic medulloblastoma. 1. J Neurosurg 1978;48:632 – 5. Inoue T, Kumabe T, Takahashi T, Nakajima T, Watanabe M, 2. Tominaga T. Spinal intramedullary metastasis of medulloblastoma at initial diagnosis. Childs Nerv Sys 2007;23:113 – 16. Barnwell SL, Edwards MS . Spinal intramedullary spread of 3. medulloblastoma. Case report. J Neurosurg 1986;65:253 – 5.

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