Branchial fistula arising from pyriform fossa: CT diagnosis of a case and discussion of radiological features.

Anomalies of third or fourth branchial apparatus origin are very uncommon and present as recurrent neck infections or thyroiditis with a predominant left-sided involvement. Radiological diagnosis requires a high index of suspicion and is critical for initiation of proper treatment. We describe a case of branchial sinus of pyriform fossa with external fistulization that presented in adulthood and was diagnosed on computed tomographic scan.

Persistence of multiple emissary veins of posterior fossa with unusual origin of left petrosquamosal sinus from mastoid emissary.

Emissary veins are valveless veins which pass through the cranial apertures and connect the dural venous sinuses and the extracranial veins. The clinical importance of emissary veins is increasingly being appreciated. Some emissary veins like the petrosquamosal sinus and mastoid emissary vein may cause significant bleeding during middle ear and skull base surgeries.