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Year : 2000  |  Volume : 10  |  Issue : 3  |  Page : 165-167
Congenital nasal mass


1 Dept of Radiology, Kasturba Medical College, Mangalore, India
2 Dept of Neurosurgery, Kasturba Medical College, Mangalore, India
3 Dept of Pediatric Surgery, Kasturba Medical College, Mangalore, India
4 Dept of Pathology, Kasturba Medical College, Mangalore, India

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Keywords: congenital nasal mass, dermoid, teratoma

How to cite this article:
Mahale A, Pai M, Prabhu R, Rao S, Lobo F. Congenital nasal mass. Indian J Radiol Imaging 2000;10:165-7

How to cite this URL:
Mahale A, Pai M, Prabhu R, Rao S, Lobo F. Congenital nasal mass. Indian J Radiol Imaging [serial online] 2000 [cited 2019 Sep 17];10:165-7. Available from: http://www.ijri.org/text.asp?2000/10/3/165/30588

   Case Report Top


A two-days-old boy presented at our hospital with respiratory distress and nasal block. On examination a pale pink swelling was seen in the left nostril.

The child was investigated using radiographs followed by a CT scan (Somatom CR, Siemens, Erlangen). The radiographs revealed a rounded opacity in the region of the nasal cavity displacing the nasal cartilage and spine to the right side with calcification and intracranial extension. The crista galli appeared to be split and displaced posteriorly. The foramen cecum was widened [Figure - 1],[Figure - 2]. Axial CT sections plain and contrast scans showed a hypodense mass in the nasal cavity with intracranial extension. The mass was calcified around its margins in the nasal cavity and showed florid calcification of its intracranial component. The nasal cartilage and spine were displaced to the right and distorted in appearance. The foramen cecum was widened and crista galli split [Figure - 3],[Figure - 4],[Figure - 5].

Our diagnosis was nasal dermoid. Histopathology was suggestive of teratoma.


   Discussion Top


During the early stages of gestation the membranous neurocranium is composed of two tissue layers which are both mesodermal and ectodermal. The external layer differentiates into inner primitive dura and outer osteogenetic layer. Nasal and frontal bones develop from membranous ossification of the latter during the seventh or eight week of gestation. The nasal capsule, which is a part of the chondrocranium (skull base) lies posterior to these bones. During the eighth week of gestation the nasal capsule is a box of cartilage divided by a median cartilagenous septum. At birth its posterior portion becomes the perpendicular plate of the ethmoid bone and its upper edge the crista galli. Two spaces are formed by nasofrontal development - 1) fonticularis fontanalles (midline between paired nasal and frontal bones. 2) prenasal space between the nasal capsule posteriorly and the nasal bone anteriorly [2].

Towards the second month of gestation a dural diverticulum extends through the prenasal space to contact the superficial nasal ectoderm. Nasal processes of frontal bone surround this dural projection to form the foramen cecum. This dural projection involutes and fibrous tissue fills the foramen cecum [2] [Figure - 6].

Normally the dural diverticula regress with time. Failure to regress or separate from the skin results in incomplete closure of the midline. This results in a wide foramen cecum with a bifid, distorted crista galli. The patency and contents of the dural diverticulum lead to the formation of dermal sinuses, dermoid cysts, nasal gliomas or encephaloceles respectively [3] [Figure - 7].

Radiographs are helpful in locating the mass prior to CT scans. They also show the bifid nature of the crista galli with widening of the foramen cecum. The crista galli measures 3-7mm (mean 4mm) and the foramen cecum 2-7mm (mean 4mm) in width. The intraorbital distance measures 13-23mm (mean 18mm) [1]. Tomograms are more useful in evaluating anatomic details [2]. The ethmoid bones may be bifid or lucent in dermal sinuses neumatization [2].

CT helps to evaluate the pre-operative extent of these lesions and helps in deciding the operative approach [3]. The intracranial extent of the mass is an indication for craniotomy. Nasal dermoids show low attenuation on CT scans with calcified extracranial components [1]. Nasal gliomas show soft tissue density and both lesions cause septal and nasal bone displacement and hypertelorism. There is evidence of a widened foramen cecum and bifid crista galli in cases with intracranial extension. Calcification of nasal gliomas has not been reported [4]. Cephaloceles show various displacements in the nasal and frontal bones depending on nasofrontal, nasoethmoidal and naso-orbital extensions. The foramen cecum is enlarged in all cases of nasoethmoidal encephalocele [1]. The classification is dependent on the location of the mass and the nomenclature is based on its contents i.e. meningocele, encephalomeningocele and meningocystocele [5].

CT scan can differentiate between glioma and encephalocele with instillation of intrathecal contrast, which fills into an encephalocele but not a glioma. MR is superior to CT in the evaluation of cephaloceles because it more clearly and non-invasively demonstrates the presence of intracranial contents and associated anomalies such as callosal agenesis and schizencephaly. Dermoids can easily be differentiated from epidermoids by their short T1 and T2 relaxation time [1]. A few diagnostic pitfalls exist

1. A normal widened nasal septum should not be mistaken for a sinus tract.

2. Fatty changes in the inferior frontal sinuses and pneumatization of the nasal bones result in low CT density and short T1 and T2 relaxation times.

These are overcome by

a) Noting the location-dermoids lie posterior to pneumatizing spaces.

b) A bony septum is normally seen between the pneumatizing spaces.

3. Mistaking crista galli or ethmoid for dermoid due to fatty changes. This can be overcome by sagittal and axial MR scans and thin section CT scans. Post surgical prognosis for epidermoid is better than for dermoids of the nasal cavity and complete excision is a key to the success of surgery [6].

 
   References Top

1.Barkovich AJ, Vandermarch P, et al . Congenital nasal masses: CT and MR Imaging features in 16 cases. AJR 1991; 156:587-598.   Back to cited text no. 1    
2.Sesion RB. Nasal Dermal Sinuses - New concepts and explanations. Laryngoscope 1982; 92 (suppl.29): 7-28.   Back to cited text no. 2    
3.Pensler JM, Bauer BS, Naidich TP. Craniofacial dermoids. Plastic and Reconstructive Surgery 1988; 82: 953-958.   Back to cited text no. 3  [PUBMED]  
4.Gorenstein A, Kern EB, Facer GW, lows Jr. Nasal gliomas. Arch Otolaryngol; 106: 536-540.   Back to cited text no. 4    
5.Suwanela C, Suwanela N. A Morphological classification of Sincipital encephalomeningocoeles. J Neurosurgery 1972; 36:201-211.   Back to cited text no. 5    
6.Bradley PJ. Results of surgery for nasal dermoids in children. J Laryngol Otol 1982; 96: 627-633.  Back to cited text no. 6  [PUBMED]  

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Correspondence Address:
Ajit Mahale
Dept of Radiodiagnosis, Univ Med Centre, Dr. BR Ambedkar Circle, Mangalore - 575 001
India
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Source of Support: None, Conflict of Interest: None


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[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8]



 

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