Second branchial cleft anomaly

General features:
Most common branchial cleft anomaly (more than 90%)
Most common anomaly is cyst (75%), present in 10 - 40 years
Fistulas and sinusespresent in first 10 years of life
1-10 cm

Classification (Bailey):
Type I: most superficial, anterior to SCM, deep to platysma
Type II (classical): most common type, along anterior surface of SCM, lateral to carotid space, posterior to SMG, at mandibular angle
Type III: medially between bifurcation of carotid to lateral pharyngeal wall , commonly between ICA and ECA
Type IV: within pharyngeal mucosal space/ pharyngeal wall

Clinical features:
Often painless, fluctuant mass anteromedial to SCM at mandibular angle
Slowly growing
May present due to infection
If fistula, ostium noted at birth just above clavicle

Imaging:
Most in submandibular space
Displaces the surrounding soft tissue
Well defined with thin wall
Anteromedial border of SCM, lateral to carotid space, at posterior margin of SMG. Thus displaces SCM posterolaterally, carotid space posteromedially, SMG anteriorly
Beak sign - considered pathognomonic- curved rim of tissue -beak- pointing medially between ICA and ECA. (Bailey type III cyst)
Rarely seen in parapharyngeal space and very rarely may present as nasopharyngeal cyst
rarely posteromedial to SCM and mimic cystic hygroma

US:
Anechoic lesion with acoustic enhancement
Compressible
Internal echoes may be seen

CT:
Homogeneously low attenuation lesion
Increased wall thickness may represent current or previous infection

MR:
Better for deep tissue extent
Cystic
Mural thickness and enhancement depend on inflammation

Beak sign:
Curved rim of tissue or beak pointing medially between ICA and ECA and is considered pathognomonic sign (Bailey type III)

Management:
Surgical excision

References:
1. Koeller KK et al. Congenital Cystic Masses of the Neck: Radiologic-Pathologic Correlation. Radiographics. 1999;19:121-146
2. Miller M, Rao V, Tom B. Cystic masses of the head and neck: pitfalls in CT and MR interpretation. AJR 1992; 159:601-607