Summary: A 5-day-old male is found to have difficulty breathing
with subsequent poor feeding.
Pyriform aperture stenosis
Axial and coronal noncontrast computed tomography (CT) images are provided. There is thickening
of the nasal processes with narrowing of the anterior nasal passage. Using the
DICOM measuring tool, the anterior nasal passage measures 5 mm. The remainder
of the airway is normal. In addition, there is a solitary maxillary central
Pyriform aperture stenosis is an uncommon congenital
condition characterized by narrowing of the anterior bony nasal passage.
Patients usually present as newborns or infants with symptoms including
dyspnea, apneic spells during feeding (newborns are obligate nasal breathers),
and/or inability to pass a nasogastric tube. In less severe cases, patients may
present slightly later when dyspnea is triggered by an upper respiratory
infection, which further narrows the airway. Some patients may also have a
narrow nasal inlet detected on physical examination.
CT is the recommended imaging modality for evaluation of the
nasal cavity as the differential diagnosis in a patient presenting with the
above symptoms includes choanal stenosis/atresia, pyriform aperture stenosis,
nasolacrimal duct mucoceles, nasopharyngeal encephalocele, and sinonasal
polyposis. Imaging features of pyriform aperture stenosis include medial
deviation and thickening of the anterior maxillae with resultant narrowing of
the nasal airway. A pyriform aperture width of <11 mm is diagnostic. Patients
may also have a triangle shaped palate, which consists of a bony ridge along
the oral surface of the hard palate on coronal images. A thorough evaluation of
the maxillary dentition is also required as the presence of a solitary
maxillary central incisor is associated with other anomalies such as
holoprosencephaly, cephaloceles, Dandy-Walker malformation, facial hemangiomas,
atrial and ventricular septal defects, and abnormalities of the genitourinary
and endocrine systems. Approximately 75% of cases of pyriform aperture stenosis
demonstrate a solitary maxillary central incisor (also known as solitary median
maxillary central incisor syndrome), and further evaluation with brain MRI is
The prognosis of pyriform aperture stenosis is excellent. Many
cases are treated conservatively with special feeding techniques. In patients
with refractory symptoms or persistent feeding difficulty, surgical
intervention with resection of the anteromedial maxilla and adjacent antero-inferior
turbinates may be indicated.
- Belden, CJ, Mancuso AA, Schmalfuss IM. CT features of congenital nasal piriform aperture
stenosis: Initial experience. Radiology. 1999;213:495-501.
- Rollins N, Booth T, Blavati M. Case 40: Congenital pyriform aperture stenosis.
- Osovsky M, et al: Congenital pyriform aperture stenosis. Pediatric Radiology. 2007;37:97-99.
- Lee JC, et al: The measurement of congenital nasal pyriform aperture stenosis in infant. Int J
Pediatr Otorhinolaryngol. 2006;70(7):1263-1267.