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Section
Congenital/Pediatric Diseases
20. Pediatric Sinonasal Disorders: Imaging
21. Pediatric Sinonasal Disorders: Surgical Perspective
5
20
CHAPTER
Pediatric Sinonasal
Disorders: Imaging
Priyanka Naranje
• Introduction
• Relevant Terminology, Anatomy,
and Pitfalls
– Terminology
– Anatomy and Pitfalls
• Imaging Modalities
• Development of Paranasal Sinuses
– Ethmoid Sinuses
– Maxillary Sinuses
– Sphenoid Sinuses
– Frontal Sinuses
• ClassicationofPediatric
Sinonasal Disorders
• Congenital Pediatric Sinonasal
Disorders
– Anterior Neuropore
– Midface Anomalies
▪ Proboscis Lateralis
▪ Nasal Cavity Anomalies
▪ Choanal Atresia
▪ Nasolacrimal Apparatus
Anomalies
• InfectiveorInammatoryPediatric
Sinonasal Disorders
– Rhinosinusiti
▪ Acute Sinusitis
▪ Chronic Sinusitis
• Tumors and Tumor-like Conditions
– Infantile Frontonasal Capillary
Hemangioma
– Teratoma
– Hamartoma
– Lipoblastoma
– Sinonasal Nerve Sheath Tumors
– Hemophilic Pseudotumor
– Sinonasal Chloroma
• Miscellaneous
– Chronic Adenoid Hypertrophy
• Illustrative Cases
– Nasal Cavity Masses
– Masses Presenting in
Frontonasal Region
– Medial Canthus Masses
– Sinus Masses
INTRODUCTION
■ A wide variety of conditions aect the nose, nasal cavity, and paranasal
sinuses in children. Many conditions, such as nasal congenital
deformities, anterior nasal cavity, or supercial frontonasal masses
can be seen on clinical examination. However, these require imaging
Section 5 Congenital/Pediatric Diseases258
evaluation for extent, determining possible intracranial extension,
dierential diagnosis, and need for biopsy.
■ Biopsy is hazardous in several conditions, such as encephalocele and
proliferating hemangioma. Contrast-enhanced computed tomography
(CECT) and magnetic resonance (MR) imaging are complementary examinations, and although MR imaging is now the preferred examination for
evaluating many of these lesions, CT may be necessary to further assess
bone changes.
RELEVANT TERMINOLOGY, ANATOMY, AND PITFALLS
Terminology
It is important to make note of various relevant surface anatomical denitions
as below:
■ Midface: It is the region located between the forehead superiorly and
upper lip inferiorly.
■ Glabella: Part of forehead between the eyebrows (above the nose).
■ Nasion: It is a point just below the glabella, bony depression in the
midline where the two nasal bones and frontal bone meet.
■ Root of nose: Depressed part of nose just below the nasion.
■ Nasofrontal region: It is a generic term used to refer to anterior neuropore
anomalies projecting in the region of glabella or root of nose and lower
forehead.
Anatomy and Pitfalls
■ Cribriform plate is nonossied in neonates—must not be misinterpreted
as being decient (Figs. 20.1A and B).
■ Cribriform plate begins to ossify between 2 months and 8 months.
■ Perpendicular plate of ethmoid begins to ossify between 4 months and
11 months.
■ ere is normally a midline gap between the two nasal bones—may be
misinterpreted as a dermal sinus tract.
■ Heterogeneous fatty marrow replacement of the sphenoid between
7 months and 2 years may mimic a sphenoid lesion.
■ Foramen cecum:
• It is a gap situated between crista galli and frontal bone.
• Normal width—up to 10 mm (mean being 4 mm).
• It appears as soft tissue density on CT and shows low to intermediate
signal intensity on magnetic resonance imaging (MRI).
■ Crista galli: Normal measurement is 1–8 mm (mean 3 mm)
• CT density and MR signal intensity are same as bone marrow.
• Age of ossication—1 year.
• Fatty replacement may be seen in majority of children and is seen by
14 years in all.
• Fatty signal can be mistaken for dermoid cyst.
A B
Figs. 20.1A and B:Unossiedcrista galliinfant(A) andnormalappearance(B)of ossied
cristagalli(thickarrows)andcribriformplate(thinarrow)ofa6-year-oldchild.
■ Measurements:
• Posterior choana: Normal size is up to 0.34 cm in children less than
2 years.
• Vomer: Normally width of posteroinferior vomer is less than 0.23 cm,
maximum is 0.55 cm in children less than 8 years.
259Chapter 20 Pediatric Sinonasal Disorders: Imaging
IMAGING MODALITIES
■ Plain radiograph has a very limited utility with poor sensitivity and
specicity.
■ Computed tomography—suces for choanal atresia, pyriform aperture
(PA) stenosis, nasolacrimal duct (NLD) anomalies, complications of
acute sinusitis, recurrent/chronic infection not responding to treatment,
evaluation of osteomeatal complex, surgical planning, bony tumors or
destruction, and facial trauma.
■ Magnetic resonance imaging—is preferred in midline mass lesions,
intracranial complications of sinusitis, and sinonasal tumors. However,
CT is often required in addition to delineate the bony defect of the
anterior skull base (ASB). MR imaging sequences that are ideal for
assessing nasal lesions include multiplanar thin-section T1-weighted
imaging, T2-weighted imaging with fat saturation, contrast materialenhanced T1-weighted imaging with fat saturation, and diusionweighted imaging.
DEVELOPMENT OF PARANASAL SINUSES
■ Paranasal sinuses form as diverticula from the walls of the nasal cavities.
■ e original openings of the diverticula persist as the ostia of the sinuses.
■ Sinuses expand and get pneumatized as the child grows (Table 20.1;
Figs. 20.2 and 20.3).
Section 5 Congenital/Pediatric Diseases260
Table 20.1: Time of appearance and maturation of paranasal sinuses.
Paranasal sinuses Appear at Attain full size
Ethmoid Present at birth Atpuberty(16–18years)
Maxillary Present but rudimentary at birth
Sphenoid 7 months to 2 years
Frontal 6–8years
A
D
Figs. 20.2A to F:Radiographicdevelopmentofparanasalsinusesaccordingtoage(A).At3
years, bilateral maxillary sinuses are partially pneumatized and their progressive enlargement
with age is seen in subsequentradiographs (B to F). Beginning of pneumatization of the
frontalsinusesisnotedattainingthefullsizeby15years(F).
B
E
C
F
A B
Figs. 20.3A and B:Hypoplasticfrontalsinusat11years.Computedtomography(CT)images
coronal(A)andaxial(B)showsnonpneumatizedfrontalsinusesat11yearsofage(arrows).
■ Familiarity with the normal chronology of these events is important
to prevent misinterpretation of partially developed/nonpneumatized
sinuses as sinusitis.
Ethmoid Sinuses
■ Present at birth and pneumatization progresses in all the directions until
the age of 12 years.
Maxillary Sinuses
■ e early phase of pneumatization is directed laterally and posteriorly
in 0–3 years, whereas the later phase proceeds inferiorly toward the
maxillary teeth at 6–12 years of age.
Sphenoid Sinuses
■ Undeveloped at birth, aeration begins 7 months to 2 years in anterior
portion of sinus and progresses posteriorly, laterally, and inferiorly. It
reaches the nerve of pterygoid canal in 6–7 years; nally reaching the
anterior wall of clivus/anterior clinoids and is completed by 9–12 years.
Frontal Sinuses
■ Not present at birth and begin to pneumatized at 6 years of age and
expanding superiorly, laterally, and medially, continue to grow in
adolescence (see Figs. 20.2 and 20.3).
261Chapter 20 Pediatric Sinonasal Disorders: Imaging
CLASSIFICATION OF PEDIATRIC SINONASAL DISORDERS
Congenital anomalies are divided based on embryology into anterior
neuropore/midface/nasobuccal region abnormalities (also see Chapters
21 and 23). For the purpose of imaging approach we have clubbed these
according to various etiologies (Table 20.2). Similarly, the “tumors” have
been clubbed according to the age of presentation (Flowchart 20.1).
SPECIFIC DISORDERS
CONGENITAL PEDIATRIC SINONASAL DISORDERS
Anterior Neuropore
Anterior neuropore abnormalities projecting in nasofrontal region include:1
■ Nasal glioma
■ Nasal encephalocele
■ Dermoid cyst
■ Epidermoid cyst
■ Nasal dermal sinus.
ese entities have been discussed in detail in Chapters 21 and 23
and illustrative cases are shown at the end of this chapter.
Midface Anomalies
Developmental errors of the central midface region include:
Section 5 Congenital/Pediatric Diseases262
Adenoid
hypertrophy
• Apert syndrome
• Crouzon syndrome
Nasolabial cysts
• Treacher Collins syndrome
• Carpenter syndrome
Neonates/infants:
Table 20.2: Classication of pediatric sinonasal disorders.
Rhinosinusitis:
Congenital Inammatory/infective Tumors and tumor-like conditions Craniofacial syndromes Miscellaneous
Anterior neuropore
• Hemangioma
• Teratoma
• Hamartoma
• Lipoblastoma
• Lipoma
• Chondroid hamartoma
• Fibroma
Older child:
(bacterial/fungal)
• Acute/chronic
• Allergic/infective
abnormalities projecting in
nasofrontal region:
• Nasal glioma
• Nasal encephalocele
• Dermoid cyst
Inammatorydiseases:
• Epidermoid cyst
• Nasal dermal sinus
Midface anomalies:
angiobroma
• Benign
– Fibro-osseouslesions
– Juvenilenasopharyngeal
– Nervesheathtumor
polyangitis
• Granulomatous
• Sarcoidosis
• Aplasias
• Hypoplasias
• Hyperplasias
Nasal cavity anomalies:
• Choanal atresia
– Hemophilicpseudotumor
• Malignant:
– Rhabdomyosarcoma
– Lymphoma
– Granulocyticsarcoma
• CNPAS
Midfacialclefts:Beyondthe
scope of this book
Nasolacrimal(NLD)apparatus
tumor(PNET)
– Primitiveneuroectodermal
– Carcinoma
anomalies
– Esthesioneuroblastoma
(CNPAS:Congenitalnasalpyriformaperturestenosis).
263Chapter 20 Pediatric Sinonasal Disorders: Imaging
Flowchart 20.1: Differential diagnosis of pediatric sinonasal masses.
(RMS: Rhabdomyosarcoma;JNA:Juvenilenasopharyngealangiobroma;NLD:Nasolacrimalduct).
Section 5 Congenital/Pediatric Diseases264
■ Aplasias—arhinia and heminasal aplasia.
■ Hypoplasias—nasal bone hypoplasia (Fig. 20.4A)/agenesis, hypoplastic
anterior nasal spine, hypoplastic nares, nasal cavity, and maxillary sinus
hypoplasia.
■ Hyperplasias—polyrhinia, supernumerary nostril, and proboscis
lateralis.
e pathogenesis of these entities is discussed in Chapter 21 and imaging
features of some of the conditions are discussed below.
Proboscis Lateralis
■ Rare hyperplastic midface malformation.
■ External nose fails to develop on one side and is replaced by a tubular
structure emanating from the medial canthus.
■ Associated with faulty development of ipsilateral paranasal sinuses
and nasolacrimal system, absent olfactory nerve, olfactory lobe, and
cribriform plate on the aected side.
■ Computed tomography reveals the single nasal cavity in normal location
and an ectopic opening of the other nose at medial canthus location.
Associated malformations of sinuses and cribriform plate are well
demonstrated on CT (Figs. 20.4B to D).
A
C
Figs. 20.4A to D:(A) Case of hypoplastic nasal bones.Arrows depict the shortened bilateral
nasalbones.(BtoD) Case of proboscis lateralis. (B) Surface rendered imageshowsthetwo
widelyseparatednasalopeningsandleftnasalopeningisseenatthelevelofleftmedialcanthus.
(C)Computed tomography (CT) axial image showsnormal right nasal cavity (arrow).(D)Left
nasalopeningisseentobeblindending(arrow)withadefectinleftfrontalbone.
B
D
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