<%server.execute "isdev.asp"%> Primary spinal intramedullary primitive neuroectodermal tumor Harbhajanka A, Jain M, Kapoor SK - J Pediatr Neurosci
home : about us : ahead of print : current issue : archives search instructions : subscriptionLogin 
Users online: 1007      Small font sizeDefault font sizeIncrease font size Print this page Email this page


 
  Table of Contents    
CASE REPORT
Year : 2012  |  Volume : 7  |  Issue : 1  |  Page : 67-69
 

Primary spinal intramedullary primitive neuroectodermal tumor


1 Department of Pathology, Lady Hardinge Medical College, New Delhi, India
2 Department of Orthopedics, Lady Hardinge Medical College, New Delhi, India

Date of Web Publication28-Jun-2012

Correspondence Address:
Manjula Jain
Department of Pathology, Lady Hardinge Medical College, New Delhi - 110 001
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1817-1745.97631

Rights and Permissions

 

   Abstract 

Though primitive neuroectodermal tumor has been considered to arise from a neoplastic transformation of primitive neuroepithelial cells with propensity to involve any part of the central nervous system, a primary intramedullary spinal primitive neuroectodermal tumor is very unusual. The authors describe a case of an 18-year-old female with conus intramedullary tumor diagnosed to be primary spinal primitive neuroectodermal tumor following histopathological examination after surgery. The diagnosis of such a tumor is very crucial as the management strategies for these are relatively unclear and are associated with a poorer outcome compared to the other common intramedullary spinal tumors.


Keywords: Intramedullary, management, primitive neuroectodermal tumor, spinal, tumor


How to cite this article:
Harbhajanka A, Jain M, Kapoor SK. Primary spinal intramedullary primitive neuroectodermal tumor. J Pediatr Neurosci 2012;7:67-9

How to cite this URL:
Harbhajanka A, Jain M, Kapoor SK. Primary spinal intramedullary primitive neuroectodermal tumor. J Pediatr Neurosci [serial online] 2012 [cited 2019 Oct 19];7:67-9. Available from: http://www.pediatricneurosciences.com/text.asp?2012/7/1/67/97631



   Introduction Top


Ever since the term primitive neuroectodermal tumor (PNET) has been proposed by Hart and Earle to define a group of malignant neoplasms of presumed neural crest origin, a number of cases of the same have been described at various locations. [1] Primary PNET of the spine is unusual with very few cases reported in the literature. [2],[3],[4] Occurrence of primary spinal PNET in an intramedullary location is further uncommon [4] ; more so in children. Very few case reports of primary pediatric spinal intramedullary PNET are reported in the literature. [3],[4],[5],[6],[7],[8],[9],[10] We describe a case of an 18-year-old female with conus intramedullary tumor diagnosed to be a spinal primary PNET following surgery The diagnosis was not suspected until the same was confirmed following final histopathological examination. The importance of recognizing the same lies in the different management strategy and therapeutic outcome compared to the usual intramedullary spinal tumors for which surgery forms the cornerstone of treatment and are associated with a better clinical outcome compared to spinal PNET.


   Case Report Top


An 18-year-old female presented with complaints of low back ache and weakness involving bilateral lower extremities for 3 months along with bowel bladder involvement for 1 week. Examination revealed tenderness in lower back with hypotonic and paraplegia (0/5 Medical Research Council grade) in bilateral lower limbs. Ninety percent sensory loss to all modalities of sensation was present with no evidence of sacral sparing. Magnetic resonance imaging (MRI) of the spine revealed an intramedullary lesion, predominantly isointense on TIW MRI with homogenous contrast enhancement and interspersed cystic/necrotic areas from D11-L2 [Figure 1] and [Figure 2]. A differential diagnosis of common intramedullary tumors namely ependymoma (myxopapillary variant), paraganglioma, other glial neoplasms, metastases or any inflammatory pathology was considered. Laminectomy and tumor decompression was performed. . Histopathology revealed a highly cellular tumor, consisting mainly of small round to oval cells with hyperchromatic nuclei and remarkably scanty cytoplasm along with the presence of Homer-Wright pseudorosettes; the tumor cells being immunopositive for CD 99 [Figure 3]. Bone scan and an intracranial MRI were done which did not reveal any evidence of tumor elsewhere and a diagnosis of primary intramedullary PNET was made. Post-operative course was uneventful with minimal improvement in power and the patient is awaiting adjuvant chemoradiotherapy.
Figure 1: T1W Magnetic resonance imaging showing a predominantly isointense intramedullary tumor

Click here to view
Figure 2: Sagittal (a) and axial (b) contrast enhanced Magnetic resonance imaging showing the homogenously enhancing intramedullary tumor with interspersed cystic/necrotic areas

Click here to view
Figure 3: Microphotograph showing a highly cellular tumor, consisting mainly of small round to oval cells with hyperchromatic nuclei and remarkably scanty cytoplasm along with the presence of Homer-Wright pseudorosettes; the tumor cells being immunopositive for CD 99 (inset)

Click here to view



   Discussion Top


PNETs are malignant tumors composed of highly undifferentiated neuroepithelial cells comprising of various lesions that are histologically similar and usually occur in the pediatric age. These are located mainly intracranially with management being surgical excision followed by craniospinal radiotherapy and a radiation boost to the primary tumor with or without chemotherapy. It has been postulated that PNETs arise from neoplastic transformation of primitive neuroepithelial cells in subependymal zones which are present in all areas of the central nervous system and may explain the presence of PNETs at locations other than the cerebellum. [2],[11] Due to unknown reasons, primary PNET involving the spine is rare and can be intramedullary, intradural-extramedullary, or epidural, with the majority arising from the cauda equina. [2],[3],[4],[12],[13],[14],[15],[16],[17],[18]

Drop metastasis from primary intracranial tumors disseminating via cerebrospinal fluid accounts for majority of spinal PNET. [2] Primary intraspinal PNETs are rare. Though, these tumors differ from central PNET in their immunohistochemical profile, genetic backgrounds and potential to metastasize outside CNS; the overall prognosis and survival is equally dismal. [2],[3],[4] Intramedullary primary PNET can present in both children and adults with no sex predilection across the whole spinal column with preferential involvement of the thoracic region. [3],[4] Intramedullary location of a primary PNET is uncommon especially in children, [3],[4],[5],[6],[7],[8],[9],[10] where glial neoplasms account for majority of intramedullary tumors. Only eight cases of clearly documented purely intramedullary spinal PNETs have been reported in the pediatric age group. [3],[4],[5],[6],[7],[8],[9],[10] Though spinal PNET behaves differently from that of spinal cord astrocytoma or ependymoma, the common tumors at this location, the imaging features does not differentiate between them. This precludes the preoperative diagnosis of spinal PNET which usually is based on the histopathological finding with confirmation by immunohistochemical analysis. However, due to rarity of spinal cord PNET, the possibility of metastasis from a central or peripheral PNET should be ruled out before arriving at the diagnosis of primary spinal PNET as was done in the described case. Magnetic resonance imaging of the whole brain and spine or a FDG PET can be performed to exclude these possibilities.

The management and prognosis of this highly uncommon lesion in this location is different from the more common tumors involving this region and is uniformly poor. In view of the good clinical response to chemoradiation in medulloblastoma or supratentorial PNET the same should be considered even in spinal PNET, not withstanding the fact that complete excision is difficult to achieve in this eloquent location.

To conclude, PNET forms a very unusual differential for intramedullary spinal tumors. Recognition of this entity at this unusual location is important for prognostication and management as these tumors involve multidisciplinary treatment with poor overall outcome compared to other intramedullary tumors of the spinal cord which it can resemble radiologically.

 
   References Top

1.Barbara J. Crain. Primitive neuroectodermal tumours. In: Wilkins RH, editor. Neurosurgery by Rengachary. Vol. 2; 1996. p. 1707-13.   Back to cited text no. 1
    
2.Deme S, Ang LC, Skaf G, Rowed DW. Primary intramedullary primitive neuroectodermal tumor of the spinal cord: Case report and review of literature. Neurosurgery 1997;1:1417-20.  Back to cited text no. 2
    
3.Kumar R, Reddy SJ, Wani AA, Pal L. Primary spinal primitive neuroectodermal tumor: Case series and review of the literature. Pediatr Neurosurg 2007;43:1-6.  Back to cited text no. 3
    
4.Otero-Rodríguez A, Hinojosa J, Esparza J, Muñoz MJ, Iglesias S, Rodríguez-Gil Y, et al. Purely intramedullary spinal cord primitive neuroectodermal tumor: Case report and review of the literature. Neurocirugia (Astur) 2009;20:381-6.  Back to cited text no. 4
    
5.Freyer DR, Hutchinson RJ, McKeever PE. Primary primitive neuroectodermal tumor of the spinal cord associated with neural tube defect. Pediatr Neurosci 1989;15:181-7.  Back to cited text no. 5
    
6.Ogasawara H, Kiya K, Kurisu K, Muttaqin Z, Uozumi T, Sugiyama K, et al. Intracranial metastasis from a spinal cord primitive neuroectodermal tumor: Case report. Surg Neurol 1992;37:307-12.  Back to cited text no. 6
    
7.Kwon OK, Wang KC, Kim CJ, Kim IO, Chi JG, Cho BK. Primary intramedullary spinal cord primitive neuroectodermal tumor with intracranial seeding in an infant. Childs Nerv Syst 1996;12:633-6.  Back to cited text no. 7
    
8.Mottl H, Koutecky J. Treatment of spinal cord tumors in children. Med Pediatr Oncol 1997;29:293-5.  Back to cited text no. 8
    
9.Kampman WA, Kros JM, De Jong TH, Lequin MH. Primitive neuroectodermal tumors (PNETs) located in the spinal canal: The relevance of classification as central or peripheral PNET. J Neurooncol 2005;15:1-8.  Back to cited text no. 9
    
10.Kim YW, Jin BH, Kim TS, Cho YE. Primary intraspinal primitive neuroectodermal tumor at conus medullaris. Yonsei Med J 2004;45:533-8.  Back to cited text no. 10
    
11.Rorke IB. The cerebellar medulloblastoma and its relationship to primitive neuroectodermal tumors. J Neuropath Exp Neurol 1983;42:1-15.  Back to cited text no. 11
    
12.Aydin MV, Sen O, Ozel S, Kayaselcuk F, Caner H, Altinors N. Primary primitive neuroectodermal tumor within the spinal epidural space: Report of a case and review of the literature. Neurol Res 2004;26:774-7.  Back to cited text no. 12
    
13.Dorfmuller G, Wurtz FG, Umschaden HW, Kleinert R, Ambros PF. Intraspinal primitive neuroectodermal tumor: Report of two cases and review of the literature. Acta Neurochir (Wien) 1999;141:1169-75.  Back to cited text no. 13
    
14.Hisaoka M, Hashimoto H, Murao T. Peripheral primitive neuroectodermal tumor with ganglioneuroma-like areas arising in the cauda equina. Virchows Arch 1997;431:365-9.  Back to cited text no. 14
    
15.Isotalo PA, Agbi C, Davidson B, Girard A, Verma S, Robertson SJ. Primary primitive neuroectodermal tumor of the cauda equina. Hum Pathol 2000;31:999-1001.  Back to cited text no. 15
    
16.Kepes JJ, Belton K, Roessmann U, Ketcherside WJ. Primitive neuroectodermal tumors of the cauda equina in adults with no detectable primary intracranial neoplasm-three case studies. Clin Neuropathol 1985;4:1-11.  Back to cited text no. 16
    
17.McDermott VG, El-Jabbour JN, Sellar RJ, Bell J. Primitive neuroectodermal tumor of the cauda equina. Neuroradiology 1994;36:228-30.  Back to cited text no. 17
    
18.Papadatos D, Albrecht S, Mohr G, Carpio-O'Donovan R. Exophytic primitive neuroectodermal tumor of the spinal cord. AJNR Am J Neuroradiol 1998;19:787-9.  Back to cited text no. 18
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]



 

Top
Print this article  Email this article
 
 
  Search
 
  
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Article in PDF (758 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  


    Abstract
   Introduction
   Case Report
   Discussion
    References
    Article Figures

 Article Access Statistics
    Viewed2013    
    Printed78    
    Emailed2    
    PDF Downloaded126    
    Comments [Add]    

Recommend this journal