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Parapharyngeal space neuroglial heterotopia with tumoral differentiation
International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology Extra journal homepage: www.elsevier.com/locate/ijporl
Case report
Parapharyngeal space neuroglial heterotopia with tumoral differentiation Joseph Y. Chan a,*, Chris K.C. Lai b, Victor J. Abdullah a, Micheal C.F. Tong c, C.A. vanHasselt c a
Department of Ear, Nose and Throat, United Christian Hospital, Hong Kong, China Department of Anatomical Cellular Pathology, Prince of Wales Hospital, Hong Kong, China c Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Hong Kong, China b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 27 May 2009 Received in revised form 22 August 2009 Accepted 26 August 2009
Introduction: Neuroglial heterotopia is a rare condition in which mature neuroglial tissue is found in the body other than in the central nervous system. Nasal glioma is neuroglial heterotopia in the nasal cavity. We report an extremely rare case of heterotopic neuroglial tissue in the temporal bone with tumoral transformation. Case report: Our patient was a 1-year-old Chinese girl. She was born with a left facial swelling. CT and MRI revealed a heterogeneous mass with cystic component occupying the parapharyngeal space. The upper airway was significantly compromised by the mass which extended into the middle cranial fossa. A combined approach to its resection was undertaken by ENT and neurosurgeons which was uneventful with all cranial nerves in its vicinity preserved. Intraoperative findings confirmed the absence of direct communication between the mass and the brain. Pathological examination confirmed mature neural tissue with tumoral differentiation. Conclusion: Heterotopic neuroglial tissue is a rare condition in the temporal bone. Ganglioglioma formation within the heterotopic neuroglial tissue is an even rarer condition. Careful pre-operative investigations and planning is the key to successful and complete excision of the abnormal tissue whilst preserving normal function. ß 2009 Elsevier Ireland Ltd. All rights reserved.
Keywords: Neuroglial heterotopia Parapharyngeal space Intracranial extension
1. Introduction Under normal conditions, neural tissue is situated in the central nervous system which is composed of brain, brainstem and spinal cord. Neuroglial heterotopia is a rare condition in which mature neuroglial tissue occurs outside the central nervous system [4]. Most cases have been reported in the nasal cavity and termed nasal glioma. Tumoral differentiation within the neuroglial heterotopia has not been reported in the English literature. The main difference between neuroglial heterotopia and encephalocele is that there is no connection with the subarachnoid space in the former [4]. Modern imaging with CT and MRI scans can delineate the extent of the mass. MRI could confirm the absence of direct communication between the lesion and central nervous system. We report a case of neuroglial heteroptopia with tumoral differentiation situated in the parapharyngeal space. It extends from the submandibular region through the skull base into the middle cranial fossa. 2. Case report The reported case is a 1-year-old Chinese girl delivered at full term by spontaneous vaginal delivery. Her mother found a left
* Corresponding author. E-mail address: [email protected] (J.Y. Chan). 1871-4048/$ – see front matter ß 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.pedex.2009.08.005
parotid mass shortly after birth which progressively increased in size. She was otherwise well with no dysmorphic features. The facial nerve and other cranial nerves were intact. Ultrasonography showed a large well-defined heterogeneous mass with both solid and cystic components in the left parotid region. MRI revealed a large left parotid mass with an internal cystic component and heterogeneous enhancement in the left infra-temporal fossa and parapharyngeal space. There was intracranial extension into the middle cranial fossa. Ultrasonography guided trucut biopsy was performed. Histology revealed small pieces of well-differentiated neuroglial tissue comprising scattered neuronal cells in a glial background. The biopsy specimen showed no primitive neuroectodermal tissue or other teratomatous component. In view of the intracranial extension, the neurosurgical team was consulted. Excision was performed under general anaesthesia with a combined approach by the ENT and neurosurgical teams. The extra-cranial component was approached via a modified Blair incision. Total parotidectomy was performed to remove the parapharyngeal component. All branches of facial nerve were identified and preserved. The lesion was removed with blunt dissection. There was a tear of the pharyngeal wall during dissection of the tumor. The tear was repaired primarily. The neurosurgeon removed the intra-cranial component with a separate question mark incision. Post-operative recovery was uneventful. Apart from mild weakness of the angle of the mouth there have been no other noticeable effects resulting from the surgery. She had normal oral feeding without the need for a
156
J.Y. Chan et al. / International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
Fig. 1. Low power H&E staining of the lesion.
tracheostomy. The final pathology confirmed the presence of welldifferentiated neuroglial tissue which contained cerebral cortical tissue with scattered neuronal cells, choroid plexus tissue and occasional cystic spaces lined by pigmented cells resembling retinal anlage. Among the neuroglial tissue, some areas showed mild to moderate increase in cellularity with an increased number and density of glial cells and ganglions. The ganglion cells showed focal abnormal clustering. Some glial cells appeared oligoid and scattered foci of calcification were present. The morphology of these cellular areas was compatible with ganglioglioma. In addition, there are a few small foci of cellular nodular lesions composed of cells with round to oval nuclei, vesicular chromatin, inconspicuous nucleoli and scant cytoplasm. They were arranged in solid sheets and nests with focal vague acinar pattern. No definite rosette formation was detected. Mitotic figures and tumor necrosis were not apparent. Immunohistochemical studies revealed that these round cells were strongly positive for neuroendocrine marker (synaptophysin) and also showed moderate positive nuclear staining to INI-1. They were however negative for epithelial markers (AE1/AE3, EMA) and GFAP. Proliferative index estimated by MIB-1 immunostain was low, less than 1%. These cellular round cell nodules present within the neuroglial tissue were suggestive of primitive neuroectodermal tumor. As demonstrated by the radiological findings, intraoperative clearance confirmed that the dura was intact. The final diagnosis was neuroglial heterotopia with tumoral differentiation,
Fig. 2. High power H&E staining of the lesion.
Fig. 3. Focus compatible with low grade ganglioglioma.
Fig. 4. MRI-coronal view.
featuring ganglioglioma and probable primitive neuroectodermal tumor. This has not been reported in world literature (Figs. 1–6). 3. Discussion Neuroglial heterotopia is a rare condition. It comprises mature neuroglial tissue situated outside the central nervous
Fig. 5. MRI axial.
J.Y. Chan et al. / International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
Fig. 6. MRI axial.
system. By definition, there is no direct communication with the subarahnoid space [4]. Most reported cases describe heterotopic neuroglial tissue situated in the nasal cavity also termed nasal glioma [1]. Other rare locations reported are the parapharyngeal space [1–3], lip, tongue, palate, pharynx, orbit, middle ear, meninges, neck and scalp. Parapharyngeal space neuroglial heterotopia is very rare [3]. Neuroglial heteroptopia with both intracranial and extra-cranial component like presented case is also rare [5]. This rare condition is reported more on the left side [1]. It also shows some female predominance among reported cases [5]. Other conditions containing mature brain tissue outside the central nervous system include enceophalocele and teratoma. However, teratoma is derived from all three germinal layers and there is communication between central nervous system in encephalocele or meningoencephalocele. The exact pathogenesis of the condition is still unknown. But there are several proposed theories [2]: (1) An encephalocele that has lost its connection with central nervous system during development. (2) Totipotential neuroectodermal tissue outside the central nervous system which develops into mature brain tissue. (3) Entrapment of olfactory bulb glial tissue outside the central nervous system. (4) Separation of primitive neuroectodermal tissue during fusion of the skull which develops into neuroglial heterotopia. Clinically, the patient usually presents shortly after birth yet some cases have presented at middle age. They may present as a neck mass, airway obstruction or dysphagia. The lesion may progressively increase in size which may be due to the production of CSF by the choroid plexus. The diagnosis usually requires biopsy of the lesion which shows mature brain tissue. 4. Pathology Neuroglial heterotopia is a term that describes the presence of brain tissue in an anatomical site that normally should not carry any neuroglial tissue. Grossly, the lesions are usually solid in nature with or without a cystic component. Histologically, it resembles mature brain tissue and may contain neurons or ganglions with glial cells in the background. The glial component may include astrocytes and oligodendrocytes. Complex structure like ependymal-lined choroid plexus can also be present. The choroid plexus can be functional producing
157
CSF which would then form a cystic structure. However, choroid plexus-like structures are reported less commonly in the nasal counterpart of neuroglial heterotopia [4]. Inflammatory cells and fibrosis are not uncommon in these lesions. Sometimes the diagnosis can be challenging because fibrosis obscures the glial background of the heterotopia in which case immunostaining of the lesion can help to establish a correct diagnosis [4]. Neural and glial specific stainings like synatophysin, chromogranin A, S100 and GFAP (glial fibrillary acidic protein) should be positive. It appears that neuroglial heterotopia with foci of ganglioglioma has not been reported in the English literature as in this case which is believed to be exceptional. The increased cellularity and proliferation of glial cells together with focal abnormal clustering of ganglion cells and scattered calcification is morphologically compatible with ganglioglioma. The significance of the scanty foci of cellular round cell nodules however is uncertain. These cells are shown to be positive for synatophysin, indicating their neuroendocrine differentiation. However, these foci are tiny and do not show rosette formation or a high proliferative index. Thus, in this case a definite diagnosis of primitive neuroectodermal tumor cannot be established. 5. Radiology Imaging is essential in the work up and management of neuroglial heterotopia. MRI scan with supplemental CT scans clearly delineate the extent of the heterotopic brain tissue. Erosion of bony structures such as pterygoid plate, mandible and skull base can be clearly demonstrated with CT scans [2]. The heterotopic brain tissue appears heterogeneous and any cystic component would represent the CSF produced by choroid plexus [3]. MRI scans delineate the size and extent of the lesion and any displacement of the surrounding soft tissue organs including the brain, parotid gland and submandibular gland. These scans would also help determine the relationship of the lesion with important structures such as, carotid arteries and jugular veins. The lesion is similar in intensity to normal brain tissue on T1-weighted images but shows high signal intensity on T2-weighted images. The cystic component is also high in signal intensity. Contrast enhancement varies with vascularity of the lesion. Another important role of MRI is in determining if any direct communication exists between the lesion and subarahnoid space [2,3]. 6. Treatment The definitive treatment is complete surgical excision of the lesion. Functional preservation is obviously of paramount importance in all patients particularly in children. Recurrence is rare and is usually the result of incomplete excision. The timing of excision is controversial. Thorough discussion with other specialists is necessary when the lesion has spread into nonotolaryngological territory. Early surgery increases the chances of complete excision at a stage when the lesion is small. This also prevents permanent deformity which can be caused by the large mass. Permanent deformity of growing bony structures might well remain. 7. Conclusion Neuroglial heterotopia is a rare clinical condition and requires consideration in the differential diagnosis of paediatric head and neck masses. MRI and CT scans can clearly delineate the extent of the mass facilitating diagnosis or limiting the differential diagnoses. The images can be of assistance in planning the management approaches. Careful dissection and complete excision is the key to successful eradication.
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J.Y. Chan et al. / International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
References [1] T.A.G.M. Huisman, U. Brehmer, G. Zeillinger, T. Stallmach, C. Gysin, Parapharyngeal neuroglial heterotopia extending through the skull base in a neonate with airway obstruction, Journal of Pediatric Surgery 42 (2007) 1764–1767. [2] P.M. Behar, S. Muller, M.E. Gerber, W. Todd, Heterotopic neuroglial tissue causing airway obstruction in the newborn, Archives of Otolaryngology Head and Neck Surgery 127 (2001) 997–1002.
[3] C.Y. Chen, J.H. Huang, W.M. Choi, C.L. Chen, W.P. Chan, Parapharyngeal neuroglial heterotopia presenting as a growing single locular cyst: mr imaging findings, American Journal of Neuroradiology 26 (2005) 96–99, Jan. [4] C.R. Penner, L.D.R. Thompson, Nasal glial heterotopia: a clinicopathologic and immunophenotypic analysis of 10 cases with a review of the literature, Annals of Diagnostic Pathology 7 (6) (2003) 354–359, Dec. [5] M.B. Marina, A.R. Zurin, W.M. Muhaizan, S.H.A. Primuharsa Putra, A.B. Azizi, M.S. Kenali, Heterotopic neuroglial tissue presenting as oral cavity mass with intracranial extension, International Journal of Pediatric Otorhinolaryngology 69 (11) (2005) 1587–1590, Nov.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology Extra journal homepage: www.elsevier.com/locate/ijporl
Case report
Parapharyngeal space neuroglial heterotopia with tumoral differentiation Joseph Y. Chan a,*, Chris K.C. Lai b, Victor J. Abdullah a, Micheal C.F. Tong c, C.A. vanHasselt c a
Department of Ear, Nose and Throat, United Christian Hospital, Hong Kong, China Department of Anatomical Cellular Pathology, Prince of Wales Hospital, Hong Kong, China c Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Hong Kong, China b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 27 May 2009 Received in revised form 22 August 2009 Accepted 26 August 2009
Introduction: Neuroglial heterotopia is a rare condition in which mature neuroglial tissue is found in the body other than in the central nervous system. Nasal glioma is neuroglial heterotopia in the nasal cavity. We report an extremely rare case of heterotopic neuroglial tissue in the temporal bone with tumoral transformation. Case report: Our patient was a 1-year-old Chinese girl. She was born with a left facial swelling. CT and MRI revealed a heterogeneous mass with cystic component occupying the parapharyngeal space. The upper airway was significantly compromised by the mass which extended into the middle cranial fossa. A combined approach to its resection was undertaken by ENT and neurosurgeons which was uneventful with all cranial nerves in its vicinity preserved. Intraoperative findings confirmed the absence of direct communication between the mass and the brain. Pathological examination confirmed mature neural tissue with tumoral differentiation. Conclusion: Heterotopic neuroglial tissue is a rare condition in the temporal bone. Ganglioglioma formation within the heterotopic neuroglial tissue is an even rarer condition. Careful pre-operative investigations and planning is the key to successful and complete excision of the abnormal tissue whilst preserving normal function. ß 2009 Elsevier Ireland Ltd. All rights reserved.
Keywords: Neuroglial heterotopia Parapharyngeal space Intracranial extension
1. Introduction Under normal conditions, neural tissue is situated in the central nervous system which is composed of brain, brainstem and spinal cord. Neuroglial heterotopia is a rare condition in which mature neuroglial tissue occurs outside the central nervous system [4]. Most cases have been reported in the nasal cavity and termed nasal glioma. Tumoral differentiation within the neuroglial heterotopia has not been reported in the English literature. The main difference between neuroglial heterotopia and encephalocele is that there is no connection with the subarachnoid space in the former [4]. Modern imaging with CT and MRI scans can delineate the extent of the mass. MRI could confirm the absence of direct communication between the lesion and central nervous system. We report a case of neuroglial heteroptopia with tumoral differentiation situated in the parapharyngeal space. It extends from the submandibular region through the skull base into the middle cranial fossa. 2. Case report The reported case is a 1-year-old Chinese girl delivered at full term by spontaneous vaginal delivery. Her mother found a left
* Corresponding author. E-mail address: [email protected] (J.Y. Chan). 1871-4048/$ – see front matter ß 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.pedex.2009.08.005
parotid mass shortly after birth which progressively increased in size. She was otherwise well with no dysmorphic features. The facial nerve and other cranial nerves were intact. Ultrasonography showed a large well-defined heterogeneous mass with both solid and cystic components in the left parotid region. MRI revealed a large left parotid mass with an internal cystic component and heterogeneous enhancement in the left infra-temporal fossa and parapharyngeal space. There was intracranial extension into the middle cranial fossa. Ultrasonography guided trucut biopsy was performed. Histology revealed small pieces of well-differentiated neuroglial tissue comprising scattered neuronal cells in a glial background. The biopsy specimen showed no primitive neuroectodermal tissue or other teratomatous component. In view of the intracranial extension, the neurosurgical team was consulted. Excision was performed under general anaesthesia with a combined approach by the ENT and neurosurgical teams. The extra-cranial component was approached via a modified Blair incision. Total parotidectomy was performed to remove the parapharyngeal component. All branches of facial nerve were identified and preserved. The lesion was removed with blunt dissection. There was a tear of the pharyngeal wall during dissection of the tumor. The tear was repaired primarily. The neurosurgeon removed the intra-cranial component with a separate question mark incision. Post-operative recovery was uneventful. Apart from mild weakness of the angle of the mouth there have been no other noticeable effects resulting from the surgery. She had normal oral feeding without the need for a
156
J.Y. Chan et al. / International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
Fig. 1. Low power H&E staining of the lesion.
tracheostomy. The final pathology confirmed the presence of welldifferentiated neuroglial tissue which contained cerebral cortical tissue with scattered neuronal cells, choroid plexus tissue and occasional cystic spaces lined by pigmented cells resembling retinal anlage. Among the neuroglial tissue, some areas showed mild to moderate increase in cellularity with an increased number and density of glial cells and ganglions. The ganglion cells showed focal abnormal clustering. Some glial cells appeared oligoid and scattered foci of calcification were present. The morphology of these cellular areas was compatible with ganglioglioma. In addition, there are a few small foci of cellular nodular lesions composed of cells with round to oval nuclei, vesicular chromatin, inconspicuous nucleoli and scant cytoplasm. They were arranged in solid sheets and nests with focal vague acinar pattern. No definite rosette formation was detected. Mitotic figures and tumor necrosis were not apparent. Immunohistochemical studies revealed that these round cells were strongly positive for neuroendocrine marker (synaptophysin) and also showed moderate positive nuclear staining to INI-1. They were however negative for epithelial markers (AE1/AE3, EMA) and GFAP. Proliferative index estimated by MIB-1 immunostain was low, less than 1%. These cellular round cell nodules present within the neuroglial tissue were suggestive of primitive neuroectodermal tumor. As demonstrated by the radiological findings, intraoperative clearance confirmed that the dura was intact. The final diagnosis was neuroglial heterotopia with tumoral differentiation,
Fig. 2. High power H&E staining of the lesion.
Fig. 3. Focus compatible with low grade ganglioglioma.
Fig. 4. MRI-coronal view.
featuring ganglioglioma and probable primitive neuroectodermal tumor. This has not been reported in world literature (Figs. 1–6). 3. Discussion Neuroglial heterotopia is a rare condition. It comprises mature neuroglial tissue situated outside the central nervous
Fig. 5. MRI axial.
J.Y. Chan et al. / International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
Fig. 6. MRI axial.
system. By definition, there is no direct communication with the subarahnoid space [4]. Most reported cases describe heterotopic neuroglial tissue situated in the nasal cavity also termed nasal glioma [1]. Other rare locations reported are the parapharyngeal space [1–3], lip, tongue, palate, pharynx, orbit, middle ear, meninges, neck and scalp. Parapharyngeal space neuroglial heterotopia is very rare [3]. Neuroglial heteroptopia with both intracranial and extra-cranial component like presented case is also rare [5]. This rare condition is reported more on the left side [1]. It also shows some female predominance among reported cases [5]. Other conditions containing mature brain tissue outside the central nervous system include enceophalocele and teratoma. However, teratoma is derived from all three germinal layers and there is communication between central nervous system in encephalocele or meningoencephalocele. The exact pathogenesis of the condition is still unknown. But there are several proposed theories [2]: (1) An encephalocele that has lost its connection with central nervous system during development. (2) Totipotential neuroectodermal tissue outside the central nervous system which develops into mature brain tissue. (3) Entrapment of olfactory bulb glial tissue outside the central nervous system. (4) Separation of primitive neuroectodermal tissue during fusion of the skull which develops into neuroglial heterotopia. Clinically, the patient usually presents shortly after birth yet some cases have presented at middle age. They may present as a neck mass, airway obstruction or dysphagia. The lesion may progressively increase in size which may be due to the production of CSF by the choroid plexus. The diagnosis usually requires biopsy of the lesion which shows mature brain tissue. 4. Pathology Neuroglial heterotopia is a term that describes the presence of brain tissue in an anatomical site that normally should not carry any neuroglial tissue. Grossly, the lesions are usually solid in nature with or without a cystic component. Histologically, it resembles mature brain tissue and may contain neurons or ganglions with glial cells in the background. The glial component may include astrocytes and oligodendrocytes. Complex structure like ependymal-lined choroid plexus can also be present. The choroid plexus can be functional producing
157
CSF which would then form a cystic structure. However, choroid plexus-like structures are reported less commonly in the nasal counterpart of neuroglial heterotopia [4]. Inflammatory cells and fibrosis are not uncommon in these lesions. Sometimes the diagnosis can be challenging because fibrosis obscures the glial background of the heterotopia in which case immunostaining of the lesion can help to establish a correct diagnosis [4]. Neural and glial specific stainings like synatophysin, chromogranin A, S100 and GFAP (glial fibrillary acidic protein) should be positive. It appears that neuroglial heterotopia with foci of ganglioglioma has not been reported in the English literature as in this case which is believed to be exceptional. The increased cellularity and proliferation of glial cells together with focal abnormal clustering of ganglion cells and scattered calcification is morphologically compatible with ganglioglioma. The significance of the scanty foci of cellular round cell nodules however is uncertain. These cells are shown to be positive for synatophysin, indicating their neuroendocrine differentiation. However, these foci are tiny and do not show rosette formation or a high proliferative index. Thus, in this case a definite diagnosis of primitive neuroectodermal tumor cannot be established. 5. Radiology Imaging is essential in the work up and management of neuroglial heterotopia. MRI scan with supplemental CT scans clearly delineate the extent of the heterotopic brain tissue. Erosion of bony structures such as pterygoid plate, mandible and skull base can be clearly demonstrated with CT scans [2]. The heterotopic brain tissue appears heterogeneous and any cystic component would represent the CSF produced by choroid plexus [3]. MRI scans delineate the size and extent of the lesion and any displacement of the surrounding soft tissue organs including the brain, parotid gland and submandibular gland. These scans would also help determine the relationship of the lesion with important structures such as, carotid arteries and jugular veins. The lesion is similar in intensity to normal brain tissue on T1-weighted images but shows high signal intensity on T2-weighted images. The cystic component is also high in signal intensity. Contrast enhancement varies with vascularity of the lesion. Another important role of MRI is in determining if any direct communication exists between the lesion and subarahnoid space [2,3]. 6. Treatment The definitive treatment is complete surgical excision of the lesion. Functional preservation is obviously of paramount importance in all patients particularly in children. Recurrence is rare and is usually the result of incomplete excision. The timing of excision is controversial. Thorough discussion with other specialists is necessary when the lesion has spread into nonotolaryngological territory. Early surgery increases the chances of complete excision at a stage when the lesion is small. This also prevents permanent deformity which can be caused by the large mass. Permanent deformity of growing bony structures might well remain. 7. Conclusion Neuroglial heterotopia is a rare clinical condition and requires consideration in the differential diagnosis of paediatric head and neck masses. MRI and CT scans can clearly delineate the extent of the mass facilitating diagnosis or limiting the differential diagnoses. The images can be of assistance in planning the management approaches. Careful dissection and complete excision is the key to successful eradication.
158
J.Y. Chan et al. / International Journal of Pediatric Otorhinolaryngology Extra 5 (2010) 155–158
References [1] T.A.G.M. Huisman, U. Brehmer, G. Zeillinger, T. Stallmach, C. Gysin, Parapharyngeal neuroglial heterotopia extending through the skull base in a neonate with airway obstruction, Journal of Pediatric Surgery 42 (2007) 1764–1767. [2] P.M. Behar, S. Muller, M.E. Gerber, W. Todd, Heterotopic neuroglial tissue causing airway obstruction in the newborn, Archives of Otolaryngology Head and Neck Surgery 127 (2001) 997–1002.
[3] C.Y. Chen, J.H. Huang, W.M. Choi, C.L. Chen, W.P. Chan, Parapharyngeal neuroglial heterotopia presenting as a growing single locular cyst: mr imaging findings, American Journal of Neuroradiology 26 (2005) 96–99, Jan. [4] C.R. Penner, L.D.R. Thompson, Nasal glial heterotopia: a clinicopathologic and immunophenotypic analysis of 10 cases with a review of the literature, Annals of Diagnostic Pathology 7 (6) (2003) 354–359, Dec. [5] M.B. Marina, A.R. Zurin, W.M. Muhaizan, S.H.A. Primuharsa Putra, A.B. Azizi, M.S. Kenali, Heterotopic neuroglial tissue presenting as oral cavity mass with intracranial extension, International Journal of Pediatric Otorhinolaryngology 69 (11) (2005) 1587–1590, Nov.