SPR Unknown # 58 -- FINAL
Publication Date: 2011-09-21
10 year old with recurrent neck abscesses
CT: There is a mildly enhancing heterogeneous mass with a hypodense center and a thick rim of peripheral enhancement posterior and medial to the left thyroid lobe. Inflammatory changes are seen within the adjacent subcutaneous fat. On coronal images, a line of enhancement extends inferiorly from the left pyriform sinus and connects to this mass.
Suppurative bacterial thyroiditis
Recurrent neck abscess in the superior pole of the thyroid should raise the possibility of a pyriform sinus fistula. A pyriform sinus fistula is a congenital lesion that occurs during embryogenesis along the spectrum of a Branchial cleft anomaly. Branchial anomalies arise from incomplete evolution of the branchial apparatus or from buried epithelial rests. They are classified according to the cleft or pouch of origin. A pyriform sinus fistula is extremely rare and is thought to occur embryologically from a 4th branchial anomaly. A 4th branchial sinus arises from the lowest point of the pyriform sinus and occurs much more commonly on the left side. Some have postulated that this represents a persistent pharyngobrachial duct.
Acute suppurative neck infections associated with branchial fistulas are frequently recurrent unless the fistula is ligated. Ultrasound with color Doppler imaging or a contrast enhanced CT are frequently used imaging modalities for evaluation of neck pathology. A barium esophagram after treatment with antibiotics is more successful in trying to demonstrate the presence of the fistula. Active inflammation or reactive edema may result in closure of the tract. If the study is to be successful, the existing infection must be cleared by appropriate antibiotics.
- Kirks D. Practical Pediatric Imaging: Diagnostic Radiology of Infants and Children. Third Edition. Philadelphia: Lippincott-Raven, 1998: 244-245.
- Gordon IO, etc. article on pyriform sinus fistula. Journal of Peds 2000; 133(7): 25-32.
- Park SW, Han MH, Myung HS, Kim IO, Kwang HK, Chang KH and Han MC. Neck Infection Associated with Pyriform Sinus Fistula: Imaging Findings. American Journal of Neuroradiology May 2000; 21:817-822.
- Lucaya J, Berdon WE, Enriquez G, Regas J, and Carreno JC. Congenital pyriform sinus fistula: A cause of acute left-sided suppurative thyroiditis and neck abscess in children. Pediatric Radiology 1990; 21(1):27-29.
- Nonomura N, Ikarashi F, Fujisaki T, and Nakano Y. Surgical approach to pyriform sinus fistula. American Journal of Otolaryngology. 1993; 14(2):111-115.
- Jacobs IN, Wyly B. The Approach to Branchial Pouch Anomalies Presenting with Airway obstruction During Infancy. Otolaryngology Head and Neck Surgery 1998; 118,682-685
- Miller D, Hill JL, Sun C, O’Brien D. and Haller J. The Diagnosis and Management of Pyriform Sinus Fistulae in Infants and Young Children. Journal of Pediatric Surgery, 18(4), 377-381