title: A combined third and fourth branchial arch anomaly: clinical and embryological implications.
abstract: Embryological abnormalities of the branchial apparatus present an interesting diagnostic and surgical challenge. Thymic cysts are a rare form of branchial apparatus anomaly, resulting from abnormal development of the third pharyngeal pouch. We present two cases of a thymic cyst coexisting with a non recurrent inferior laryngeal nerve (NRILN), two anomalies that to our knowledge have not been associated previously. A possible embryological explication for this double abnormality is discussed, while the clinical implications of this association are presented.
authors.affiliation: Department of Otolaryngology, St. Mary's Hospital, Paddington, London, UK.
authors.forename: H
authors.initials: H
authors.lastname: Mehrzad
authors.forename: C
authors.initials: C
authors.lastname: Georgalas
authors.forename: C
authors.initials: C
authors.lastname: Huins
authors.forename: N S
authors.initials: NS
authors.lastname: Tolley
mesh_terms: D000015:Abnormalities, Multiple; D000328:Adult; D001934:Branchial Region / Q000002:abnormalities*; D001935:Branchioma / Q000175:diagnosis*; D003560:Cysts / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D010608:Pharyngeal Diseases / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed