Abstract
A pyriform sinus fistula is a rare congenital abnormality of the third or fourth branchial pouch that usually affects children. We report one case of the condition; ultrasound (US) imaged a heterogeneous mass with a hypoechoic area and air bubbles representing an abscess. Although these manifestations are rare, prominent and characteristic findings on US may facilitate the diagnosis of pyriform sinus fistula.
1
Introduction
A pyriform sinus fistula is uncommon and typically presents as a congenital sinus tract; it usually occurs in children [ ]. A left-sided fistula is more common than a right-sided fistula [ ]. Pyriform sinus fistulas often cause recurrent cervical suppurative infections or neck abscesses with swelling and tenderness in children [ ]. An early diagnosis, as well as incision and drainage of the fistula, prevents recurrence of cervical infections. As a simple and non-invasive examination, US plays a significant and useful role on the diagnosis of a pyriform sinus fistula. To emphasize the US characteristics, we present one case of pyriform sinus fistula that was treated in our hospital. Barium Swallow can confirm the disease.
2
Case report
A four-year-old boy was admitted to our hospital with a mass in the left side of the neck, which appeared two days earlier, and a fever of seven days’ duration. The white blood cell count was 11.92×10 9 /L. Physical examination revealed tenderness and a palpable mass in the left lobe of the thyroid gland. Thyroid function tests and thyroid antibody titers were normal.
Cervical US exam was requested. On cervical US, an ill-defined, heterogeneous mass measuring 3.2 × 1.8 cm was found with hypoechoic area and air bubbles in the left lobe of the thyroid gland; color Doppler Flow Imaging (CDFI) revealed a rich blood flow within the mass ( Fig. 1 ). The adjacent cervical lymph nodes were enlarged. The rest of the left lobe of the thyroid gland was normal. After repeated swallowing, Barium Swallow showed a short fistula arising from the left pyriform sinus and extending down ( Fig. 2 ).
According to the above imaging findings, the child was diagnosed with a pyriform sinus fistula; the symptoms resolved after receiving surgical drainage and anti-inflammatory treatment.
2
Case report
A four-year-old boy was admitted to our hospital with a mass in the left side of the neck, which appeared two days earlier, and a fever of seven days’ duration. The white blood cell count was 11.92×10 9 /L. Physical examination revealed tenderness and a palpable mass in the left lobe of the thyroid gland. Thyroid function tests and thyroid antibody titers were normal.
Cervical US exam was requested. On cervical US, an ill-defined, heterogeneous mass measuring 3.2 × 1.8 cm was found with hypoechoic area and air bubbles in the left lobe of the thyroid gland; color Doppler Flow Imaging (CDFI) revealed a rich blood flow within the mass ( Fig. 1 ). The adjacent cervical lymph nodes were enlarged. The rest of the left lobe of the thyroid gland was normal. After repeated swallowing, Barium Swallow showed a short fistula arising from the left pyriform sinus and extending down ( Fig. 2 ).
