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Heterotopic brain in the parapharyngeal space
INTERNATIONALJOURNALOF
Pediatric International
Journal of Pediatric Otorhinolaryngology 37 (1996) 253-260
ELSEVIER
Case report
Heterotopic brain in the parapharyngeal space Vito Forte*, Department
of Pediatric
Received
Jacob Friedberg, Otolaryngology,
12 March
Hospital Ont. M5G 1996; revised
Paul Thorner, of Sick Children, 1X8, Canada 5 June
Albert Park
555 University
1996; accepted
Avenue,
Toronto,
8 June 1996
Abstract
There have beennumerousreports of various types of heterotopic tissuein the head and neck. Heterotopic cartilage, gastric tissue, thyroid, and salivary gland in such various locationsastongue,gingiva, palate, nasopharynx,parapharyngealspace,and neck have been frequently reported. Heterotopic brain in the parapharyngealspacecausingairway obstruction in the neonatehasbeenrarely described.Thesebenignmasses are capableof expansion and becauseof their location, can lead to significant airway and feeding difficulties. We describe3 casesof heterotopic brain tissuein the parapharyngealspacecausing feeding difficulties and airway obstruction in the neonatalperiod. Two wereinitially misdiagnosed as lymphatic malformations. In the third, a nine month delay in diagnosisoccurred. The diagnosticfeaturesof heterotopicbrain in this location and somemanagementsuggestions in treating such a lesion are discussed. Keywords:
Heterotopic brain; Parapharyngealspace
1. Introduction: Heterotopic tissue consists of histologically normal tissue that is situated in an abnormal location. Most studies concerning hetertopic tissue in the newborn have * Corresponding 0165-5876/96/$15.00
author,
Tel.:
+ 1 416 8136767.
0 1996 Elsevier
PII SOl65-SS76(96)01401-2
Science
Ireland
Ltd.
All rights
reserved
254
V. Forte et al. 1 Int. J. Pediatr. Otorhinolaryngol. 37 (1996) 253-260
described nasal gliomas within the nasal cavity [l]. These patients often present with nasal obstruction or a mass. The tissue consists of astrocytes and neuroglial fibers within a fibrous, vascularized connective tissue. There is no direct communication with the central nervous system; however, the description of hetertopic tissue outside the nasal cavity is unusual [2-61. Three cases of hetertopic brain tissue presenting in the neonatal period with respiratory distress are described. The evaluation, workup and treatment of this lesion are presented.
2. Case report 2.1. Case 1 A three day old male infant was transferred to the Hospital for Sick Children (HSC) for difficulty breathing and feeding and for evaluation of a neck mass. The pregnancy had been normal and after delivery Apgar scores were 8 and 9 at 1 and 5 min respectively. The infant presented with stridor, intercostal indrawing, and a large lateral cervicofacial mass involving the jugulodigastric and parotid region. The mass was compressible on palpation. A CT scan showed a multicystic lesion measuring 4 x 4 cm compressing the hypopharynx and larynx as well as extending around the mandible and onto the face in the region of the parotid gland. The left ramus and body of the mandible as well as the left pterygoid plate were deformed by the mass (Fig. 1). Because of the extent of the lesion and his deteriorating respiratory status, the child was taken to the operating room for resection of what was presumed to be a lymphatic malformation. A cervicofacial approach via an extended parotidectomy incision was performed, and a multiloculated mass was dissected free from the facial nerve. Removal of the inferior extent of the lesion required dissection of pharyngeal musculature. The infant’s immediate postoperative course was smooth, facial nerve function was normal and the child tolerated oral feeds. Unfortunately, the infant failed to thrive and his respiratory and feeding difficulties recurred 4 months after the initial surgery. A repeat CT scan was performed and showed a cystic mass involving the parapharyngeal space, displacing the soft palate and lateral pharyngeal wall compromising the oral and nasopharyngeal airway. He was subsequently taken to the operating room, and a transoral-transpharyngopalatal approach was utilized to remove a cystic, partially encapsulated lesion. The child’s postoperative course was uneventful with complete resolution of symptoms. Histopathology revealed heterotopic brain tissue composed of mature glial tissue (Fig. 2) with some ependymal differentiation and cystic areas lined by choroid plexus (Fig. 3). There has been no recurrence with a six year follow-up.
V. Forte
et al. 1 Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
255
2.2. Case 2
This full term female infant, reportedly underwent resection, at another hospital, of a left cervical lymphatic malformation at age 4 weeks. She presented to our institution at 10 weeks of age with failure to thrive and progressive obstructive respiratory distress requiring support with a nasopharyngeal airway. The infant had a large parapharyngeal mass displacing the left soft palate and lateral pharyngeal wall compromising the oronasal airway. A CT scan showed a multicystic mass of the left parapharyngeal space, extending into the soft palate and inferiorly to the left piriform sinus. Bony deformity of the left mandible and pterygoid plate were also noted (Fig. 4).
Fig. 1. Axial CT scan of Case 1 showing multicystic parapharyngeal mass deforming pterygoid plate and mandible on left side.
256
V. Forte
et al. 1 Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
Fig. 2. Low power view of mass excised from Case 1 showing mature neuroglial tissue adjacent to skeletal muscle (hematoxylin and eosin, x 65).
Excision of the mass through a transoral approach was performed. Post-operatively she did well and was discharged home 7 days later. Histologic examination of the specimen revealed mature neuroglial tissue containing foci of ependymal cells and choroid plexus formation. Six year follow-up reveals no recurrence of disease. 2.3. Case 3
A nine month old female infant with Pierre-Robin syndrome was referred to the otolaryngology clinic for evaluation of a soft palatal mass. Her prenatal history and
V. Forte
et al. / Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
251
253-260
delivery were unremarkable. An incomplete cleft palate and retrognathia were noted leading to respiratory and feeding difficulties. She required percutaneous G-tube placement for nutritional purposes and a nasopharyngeal tube for airway support. At four months, the nasopharyngeal tube was discontinued but mild obstructive respiratory problems persisted during sleep only. Subsequently at the time of assessment the child was noted to be well-nourished and developmentally normal. Intraorally, there was a 4 x 4 cm firm, submucosal lesion involving the left side of the partially cleft palate and lateral nasopharynx. The remainder of the head and neck examination was unremarkable. A CT scan
Fig. 3. Higher power view neuroglial tissue (hematoxylin
of Case 1 showing and eosin, x 400).
choroid
plexus
formations
surrounded
by
mature
258
V. Forte
et al. / Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
Fig. 4. Axial CT scan of Case 2 showing characteristic deformity of pterygoid and mandible by multicystic parapharyngeal mass.
illustrated a loculated soft tissue mass of the soft palate, extending into the parapharyngeal and infratemporal fossa. Abundant fat was noted in the infratemporal fossa with the normal fat planes being obscured. The zygoma and pterygoid plates were deformed. An MRI scan was also performed and illustrated similar pathology. No intracranial connections were noted. Transoral resection of the mass was carried out after the frozen section revealed heterotopic brain tissue. The final histology confirmed this diagnosis. Postoperatively, the child did well with no recurrent disease with a 9 month follow-up.
V. Forte
et al. 1 Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
259
3. Discussion The term ‘heterotopia’ refers to normal tissue in an abnormal location and may be used synonymously with the term ‘choristoma’, although some reserve the term choristoma to denote a ‘tumor-like’ mass of normal tissue in an abnormal location [2]. Nasal glioma is the most common type of heterotopic brain tissue in the head and neck region [l]. Encephaloceles are not considered as heterotopic tissue since by definition, they represent herniation of brain through a skull defect. The occurrence of heterotopic brain tissue involving the soft palate and parapharyngeal space is rare with fewer than 20 cases reported in the literature [1,7- 111. Patients typically present as neonates with respiratory distress. A significant number of these patients have an associated cleft palate. A non-midline soft palatal submucosal mass extending into the nasopharynx is observed. One case described multiple areas of heterotopic brain tissue involving the right temple, right oropharynx and right subdigastric area. There are several theories regarding the origin of this cerebral heterotopia. One theory suggests derivation from an encephalocele which has lost its connection to the subarachnoid space [7,11,12]. This theory is supported by an observation that nasal cerebral heterotopias (nasal gliomas) can have a fibrous connection to intracranial contents. Another theory hypothesizes that neuroectodermal tissue develops from multipotent cells during embryogenesis [ 11,13,14]. Supporting this theory is the finding that nasal gliomas and extranasal heterotopic brain contain different histologic elements. Extranasal heterotopic tissue contains neurons, glial cells, mature ependyma and choroid plexus. Nasal heterotopic tissue (nasal gliomas) on the other hand do not contain choroid plexus, ependyma and rarely contain neurons. A neonate with a soft palatal mass should be suspected of having heterotopic brain tissue. Since neonates are obligate nasal breathers, a mass involving the soft palate might significantly affect the airway. Initial management may involve the placement of a nasopharyngeal or endotracheal tube to bypass the obstruction. Imaging with CT and/or MRI is obligatory for diagnostic reasons as well as for surgical planning. Intracranial connection must be ruled out. A basal encephalocele may enter into the nasopharynx via a defect between the posterior cribriform and posterior clinoid. Differential diagnosis also includes lymphatic malformation. These lesions are soft, compressible and often multiloculated masses. The radiographic features reflect this multiloculated feature and may lead to an incorrect diagnosis as in case one. Heterotopic brain tissue, as seen from this series, may include cytic as well as solid components an can extend from the soft palate into the peritonsillar, parapharyngeal, and infratemporal fossa spaces. There often is a lateral component of fatty tissue in the infratemporal fossa and bony distortion of the mandible or ptyergoid plates as was seen clearly on the CT scans of all three cases. This distortion of bone is not typically seen at birth with lymphatic malformations making CT a crucial distinguishing investigation. The definitive management of these lesions is surgical resection. Some authors have tried drainage of heterotopic brain cysts in the neck, but this technique
260
V. Forte
et al. 1 ht.
J. Pediatr.
Otorliinolaryngol.
37 (1996)
253-260
invariably results in the rapid reaccumulation of fluid [8,15]. Maintenance of an airway with a nasopharyngeal tube or a tracheotomy is an option that is not recommended given the excellent results obtained from surgical excision. The transoral surgical approach is preferred but will depend on the site and extent of the lesion. A simple modification of the Dingman retractor by shortening the tongue blade facilitates this approach in smaller infants. Preoperative planning is crucial especially when the infant has a soft palate cleft. The incisions should be performed in a manner that will not adversely affect future palatal reconstruction. Removal of the mass should relieve the obstructive component and permit immediate extubation. Complete or near-complete resection should result in cure.
References [I] Broniatowski, M., Witt, W.J.. Shah, A.C. et al. (1981) Glial tissue in the parapharyngeal space. Arch. Otolaryngol. 107, 63% 641. [2] Trowbridge, M., McCabe, B. and Reznicek, M. (1989) Cartilaginous Choristoma of the Tongue. A Case report and literature review. Arch. Otolaryngol. Head Neck Surg. 115(5), 627-629. [3] Johnston, C., Benjamin, B., Harrison, II., Kan, A. et al. (1989) Gastric heterotopia causing airway obstruction. Int. J. Pediatr. Otolaryngol. 18(I), 67-72. [4] Nash, M., Cho, H. and Cohen, J. (1988) Salivary choristomas in the neck. Otolaryngol. Head Neck Surg. 99(6), 590-593. [5] West, C.B., Jr. and Atkins, J.S., Jr. (1988) Choristomas of the intraoral soft tissues. Otolaryngol. Head Neck Surg. 99(5), 528-530. [6] Chou, L.S., Hansen, L.S. and Danieis TE. (1991) Choristomas of the oral cavity: a review. Oral Surg. Oral Med. Oral Pathol. 72, 584-593. [7] Okulski, E.G., Biemer, J.J. and Alonso, W.A. (1981) Heterotopic pharyngeal brain. Arch. Otolaryngo]. 107: 385. 386. [S] Lasjaunias, P., Ginisty, D., Comoy, J. et al. (I985-861) Ectopic secreting choroid plexus in the oropharynx. Pediat. Neurosci. 12, 205 -207. [9] Seibert, R.W., Seibert, J.J., Jimenez, J.F.. Angtuaco, E.J. et al. (1984) Nasopharyngeal brain heterotopia a cause of upper airway obstruction in infancy. Laryngoscope 94, 818-819. [IO] Lim, R.Y., (1991) Capinpin AG. Extensive heterotopic brain tissue of the head and neck. Otolaryngol. Head Neck Surg. 105, 469-472. [I l] Hendrickson, M., Faye-Peterson. 0. and Johnson, D.G. (1990) Cystic and solid heterotopic brain in the face and neck: a review and report of an unusual case. J. Pediatr. Surg. 25(7), 766-768. [I21 Yeoh, G.P., Bale, P.M. and deSilva, M. (1989) Nasal cerebral heterotopia: the so-called nasal glioma or sequestered encephaloceie and its variants. Pediatr. Pathoi. 9, 5531-5549. [I31 Zook, E.G., Nickey, W.M. and Pribaz, J.J. (1984) Heterotopic brain tissue in the scalp. Plast. Reconstr. Surg. 73, 660-663. [14] Al-Nafussi, A.M., Hancock, K., Sommerlad. B. et al. (1990) Heterotopic brain presenting as a cystic mass of the palate. Histopathol. 17, 81-84. [15J Misra, B.K., Shaw, J.F. and Gordon, A. (1987) Heterotopic brain cyst from middle cranial fossa to submandibular region. Child’s Nerv. Syst. 3, 297-300.
Pediatric International
Journal of Pediatric Otorhinolaryngology 37 (1996) 253-260
ELSEVIER
Case report
Heterotopic brain in the parapharyngeal space Vito Forte*, Department
of Pediatric
Received
Jacob Friedberg, Otolaryngology,
12 March
Hospital Ont. M5G 1996; revised
Paul Thorner, of Sick Children, 1X8, Canada 5 June
Albert Park
555 University
1996; accepted
Avenue,
Toronto,
8 June 1996
Abstract
There have beennumerousreports of various types of heterotopic tissuein the head and neck. Heterotopic cartilage, gastric tissue, thyroid, and salivary gland in such various locationsastongue,gingiva, palate, nasopharynx,parapharyngealspace,and neck have been frequently reported. Heterotopic brain in the parapharyngealspacecausingairway obstruction in the neonatehasbeenrarely described.Thesebenignmasses are capableof expansion and becauseof their location, can lead to significant airway and feeding difficulties. We describe3 casesof heterotopic brain tissuein the parapharyngealspacecausing feeding difficulties and airway obstruction in the neonatalperiod. Two wereinitially misdiagnosed as lymphatic malformations. In the third, a nine month delay in diagnosisoccurred. The diagnosticfeaturesof heterotopicbrain in this location and somemanagementsuggestions in treating such a lesion are discussed. Keywords:
Heterotopic brain; Parapharyngealspace
1. Introduction: Heterotopic tissue consists of histologically normal tissue that is situated in an abnormal location. Most studies concerning hetertopic tissue in the newborn have * Corresponding 0165-5876/96/$15.00
author,
Tel.:
+ 1 416 8136767.
0 1996 Elsevier
PII SOl65-SS76(96)01401-2
Science
Ireland
Ltd.
All rights
reserved
254
V. Forte et al. 1 Int. J. Pediatr. Otorhinolaryngol. 37 (1996) 253-260
described nasal gliomas within the nasal cavity [l]. These patients often present with nasal obstruction or a mass. The tissue consists of astrocytes and neuroglial fibers within a fibrous, vascularized connective tissue. There is no direct communication with the central nervous system; however, the description of hetertopic tissue outside the nasal cavity is unusual [2-61. Three cases of hetertopic brain tissue presenting in the neonatal period with respiratory distress are described. The evaluation, workup and treatment of this lesion are presented.
2. Case report 2.1. Case 1 A three day old male infant was transferred to the Hospital for Sick Children (HSC) for difficulty breathing and feeding and for evaluation of a neck mass. The pregnancy had been normal and after delivery Apgar scores were 8 and 9 at 1 and 5 min respectively. The infant presented with stridor, intercostal indrawing, and a large lateral cervicofacial mass involving the jugulodigastric and parotid region. The mass was compressible on palpation. A CT scan showed a multicystic lesion measuring 4 x 4 cm compressing the hypopharynx and larynx as well as extending around the mandible and onto the face in the region of the parotid gland. The left ramus and body of the mandible as well as the left pterygoid plate were deformed by the mass (Fig. 1). Because of the extent of the lesion and his deteriorating respiratory status, the child was taken to the operating room for resection of what was presumed to be a lymphatic malformation. A cervicofacial approach via an extended parotidectomy incision was performed, and a multiloculated mass was dissected free from the facial nerve. Removal of the inferior extent of the lesion required dissection of pharyngeal musculature. The infant’s immediate postoperative course was smooth, facial nerve function was normal and the child tolerated oral feeds. Unfortunately, the infant failed to thrive and his respiratory and feeding difficulties recurred 4 months after the initial surgery. A repeat CT scan was performed and showed a cystic mass involving the parapharyngeal space, displacing the soft palate and lateral pharyngeal wall compromising the oral and nasopharyngeal airway. He was subsequently taken to the operating room, and a transoral-transpharyngopalatal approach was utilized to remove a cystic, partially encapsulated lesion. The child’s postoperative course was uneventful with complete resolution of symptoms. Histopathology revealed heterotopic brain tissue composed of mature glial tissue (Fig. 2) with some ependymal differentiation and cystic areas lined by choroid plexus (Fig. 3). There has been no recurrence with a six year follow-up.
V. Forte
et al. 1 Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
255
2.2. Case 2
This full term female infant, reportedly underwent resection, at another hospital, of a left cervical lymphatic malformation at age 4 weeks. She presented to our institution at 10 weeks of age with failure to thrive and progressive obstructive respiratory distress requiring support with a nasopharyngeal airway. The infant had a large parapharyngeal mass displacing the left soft palate and lateral pharyngeal wall compromising the oronasal airway. A CT scan showed a multicystic mass of the left parapharyngeal space, extending into the soft palate and inferiorly to the left piriform sinus. Bony deformity of the left mandible and pterygoid plate were also noted (Fig. 4).
Fig. 1. Axial CT scan of Case 1 showing multicystic parapharyngeal mass deforming pterygoid plate and mandible on left side.
256
V. Forte
et al. 1 Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
Fig. 2. Low power view of mass excised from Case 1 showing mature neuroglial tissue adjacent to skeletal muscle (hematoxylin and eosin, x 65).
Excision of the mass through a transoral approach was performed. Post-operatively she did well and was discharged home 7 days later. Histologic examination of the specimen revealed mature neuroglial tissue containing foci of ependymal cells and choroid plexus formation. Six year follow-up reveals no recurrence of disease. 2.3. Case 3
A nine month old female infant with Pierre-Robin syndrome was referred to the otolaryngology clinic for evaluation of a soft palatal mass. Her prenatal history and
V. Forte
et al. / Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
251
253-260
delivery were unremarkable. An incomplete cleft palate and retrognathia were noted leading to respiratory and feeding difficulties. She required percutaneous G-tube placement for nutritional purposes and a nasopharyngeal tube for airway support. At four months, the nasopharyngeal tube was discontinued but mild obstructive respiratory problems persisted during sleep only. Subsequently at the time of assessment the child was noted to be well-nourished and developmentally normal. Intraorally, there was a 4 x 4 cm firm, submucosal lesion involving the left side of the partially cleft palate and lateral nasopharynx. The remainder of the head and neck examination was unremarkable. A CT scan
Fig. 3. Higher power view neuroglial tissue (hematoxylin
of Case 1 showing and eosin, x 400).
choroid
plexus
formations
surrounded
by
mature
258
V. Forte
et al. / Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
Fig. 4. Axial CT scan of Case 2 showing characteristic deformity of pterygoid and mandible by multicystic parapharyngeal mass.
illustrated a loculated soft tissue mass of the soft palate, extending into the parapharyngeal and infratemporal fossa. Abundant fat was noted in the infratemporal fossa with the normal fat planes being obscured. The zygoma and pterygoid plates were deformed. An MRI scan was also performed and illustrated similar pathology. No intracranial connections were noted. Transoral resection of the mass was carried out after the frozen section revealed heterotopic brain tissue. The final histology confirmed this diagnosis. Postoperatively, the child did well with no recurrent disease with a 9 month follow-up.
V. Forte
et al. 1 Int. J. Pediatr.
Otorhinolaryngol.
37 (1996)
253-260
259
3. Discussion The term ‘heterotopia’ refers to normal tissue in an abnormal location and may be used synonymously with the term ‘choristoma’, although some reserve the term choristoma to denote a ‘tumor-like’ mass of normal tissue in an abnormal location [2]. Nasal glioma is the most common type of heterotopic brain tissue in the head and neck region [l]. Encephaloceles are not considered as heterotopic tissue since by definition, they represent herniation of brain through a skull defect. The occurrence of heterotopic brain tissue involving the soft palate and parapharyngeal space is rare with fewer than 20 cases reported in the literature [1,7- 111. Patients typically present as neonates with respiratory distress. A significant number of these patients have an associated cleft palate. A non-midline soft palatal submucosal mass extending into the nasopharynx is observed. One case described multiple areas of heterotopic brain tissue involving the right temple, right oropharynx and right subdigastric area. There are several theories regarding the origin of this cerebral heterotopia. One theory suggests derivation from an encephalocele which has lost its connection to the subarachnoid space [7,11,12]. This theory is supported by an observation that nasal cerebral heterotopias (nasal gliomas) can have a fibrous connection to intracranial contents. Another theory hypothesizes that neuroectodermal tissue develops from multipotent cells during embryogenesis [ 11,13,14]. Supporting this theory is the finding that nasal gliomas and extranasal heterotopic brain contain different histologic elements. Extranasal heterotopic tissue contains neurons, glial cells, mature ependyma and choroid plexus. Nasal heterotopic tissue (nasal gliomas) on the other hand do not contain choroid plexus, ependyma and rarely contain neurons. A neonate with a soft palatal mass should be suspected of having heterotopic brain tissue. Since neonates are obligate nasal breathers, a mass involving the soft palate might significantly affect the airway. Initial management may involve the placement of a nasopharyngeal or endotracheal tube to bypass the obstruction. Imaging with CT and/or MRI is obligatory for diagnostic reasons as well as for surgical planning. Intracranial connection must be ruled out. A basal encephalocele may enter into the nasopharynx via a defect between the posterior cribriform and posterior clinoid. Differential diagnosis also includes lymphatic malformation. These lesions are soft, compressible and often multiloculated masses. The radiographic features reflect this multiloculated feature and may lead to an incorrect diagnosis as in case one. Heterotopic brain tissue, as seen from this series, may include cytic as well as solid components an can extend from the soft palate into the peritonsillar, parapharyngeal, and infratemporal fossa spaces. There often is a lateral component of fatty tissue in the infratemporal fossa and bony distortion of the mandible or ptyergoid plates as was seen clearly on the CT scans of all three cases. This distortion of bone is not typically seen at birth with lymphatic malformations making CT a crucial distinguishing investigation. The definitive management of these lesions is surgical resection. Some authors have tried drainage of heterotopic brain cysts in the neck, but this technique
260
V. Forte
et al. 1 ht.
J. Pediatr.
Otorliinolaryngol.
37 (1996)
253-260
invariably results in the rapid reaccumulation of fluid [8,15]. Maintenance of an airway with a nasopharyngeal tube or a tracheotomy is an option that is not recommended given the excellent results obtained from surgical excision. The transoral surgical approach is preferred but will depend on the site and extent of the lesion. A simple modification of the Dingman retractor by shortening the tongue blade facilitates this approach in smaller infants. Preoperative planning is crucial especially when the infant has a soft palate cleft. The incisions should be performed in a manner that will not adversely affect future palatal reconstruction. Removal of the mass should relieve the obstructive component and permit immediate extubation. Complete or near-complete resection should result in cure.
References [I] Broniatowski, M., Witt, W.J.. Shah, A.C. et al. (1981) Glial tissue in the parapharyngeal space. Arch. Otolaryngol. 107, 63% 641. [2] Trowbridge, M., McCabe, B. and Reznicek, M. (1989) Cartilaginous Choristoma of the Tongue. A Case report and literature review. Arch. Otolaryngol. Head Neck Surg. 115(5), 627-629. [3] Johnston, C., Benjamin, B., Harrison, II., Kan, A. et al. (1989) Gastric heterotopia causing airway obstruction. Int. J. Pediatr. Otolaryngol. 18(I), 67-72. [4] Nash, M., Cho, H. and Cohen, J. (1988) Salivary choristomas in the neck. Otolaryngol. Head Neck Surg. 99(6), 590-593. [5] West, C.B., Jr. and Atkins, J.S., Jr. (1988) Choristomas of the intraoral soft tissues. Otolaryngol. Head Neck Surg. 99(5), 528-530. [6] Chou, L.S., Hansen, L.S. and Danieis TE. (1991) Choristomas of the oral cavity: a review. Oral Surg. Oral Med. Oral Pathol. 72, 584-593. [7] Okulski, E.G., Biemer, J.J. and Alonso, W.A. (1981) Heterotopic pharyngeal brain. Arch. Otolaryngo]. 107: 385. 386. [S] Lasjaunias, P., Ginisty, D., Comoy, J. et al. (I985-861) Ectopic secreting choroid plexus in the oropharynx. Pediat. Neurosci. 12, 205 -207. [9] Seibert, R.W., Seibert, J.J., Jimenez, J.F.. Angtuaco, E.J. et al. (1984) Nasopharyngeal brain heterotopia a cause of upper airway obstruction in infancy. Laryngoscope 94, 818-819. [IO] Lim, R.Y., (1991) Capinpin AG. Extensive heterotopic brain tissue of the head and neck. Otolaryngol. Head Neck Surg. 105, 469-472. [I l] Hendrickson, M., Faye-Peterson. 0. and Johnson, D.G. (1990) Cystic and solid heterotopic brain in the face and neck: a review and report of an unusual case. J. Pediatr. Surg. 25(7), 766-768. [I21 Yeoh, G.P., Bale, P.M. and deSilva, M. (1989) Nasal cerebral heterotopia: the so-called nasal glioma or sequestered encephaloceie and its variants. Pediatr. Pathoi. 9, 5531-5549. [I31 Zook, E.G., Nickey, W.M. and Pribaz, J.J. (1984) Heterotopic brain tissue in the scalp. Plast. Reconstr. Surg. 73, 660-663. [14] Al-Nafussi, A.M., Hancock, K., Sommerlad. B. et al. (1990) Heterotopic brain presenting as a cystic mass of the palate. Histopathol. 17, 81-84. [15J Misra, B.K., Shaw, J.F. and Gordon, A. (1987) Heterotopic brain cyst from middle cranial fossa to submandibular region. Child’s Nerv. Syst. 3, 297-300.