Acute suppurative thyroiditis in a child with congenital third/fourth branchial arch anomaly: a case report.

Third and fourth branchial arch anomalies belong to congenital lesions which are extremely rare accounting for <1-4% of branchial arch anomalies. In our case, a 4-year-old boy was admitted to our hospital with a painful mass on the left side of his neck. The imaging and clinical findings are oriented to the diagnosis of suppurative thyroiditis with underlying third/fourth branchial arch anomaly. The diagnosis was confirmed with laryngoscopy and the child was treated with endoscopic cauterization. The presence of specific clinical and imaging findings is not definitive, so the diagnosis relies on having a strong suspicion and knowledge of typical locations. So, our purpose is to present the spectrum of relative imaging findings from at least three imaging modalities in order to increase the level of clinical and radiological suspicion of that rare condition and help with accurate diagnosis and planning of the treatment.