First Branchial Cleft Cyst

  • Etiology:
    — Remnant of embryonal branchial arch incompletely obliterated
    — Parotid cyst extending to external auditory canal at osteochondral junction of external auditory canal
  • Imaging: Look near parotid gland and ear or external auditory canal
  • DDX:
  • Complications: Infection
  • Treatment:
  • Clinical:
    — 5% of branchial cleft cysts
    — Presents with otorrhea and external auditory canal or peri-parotid mass
    — With unexplained abscess in the neck look for branchial cleft anomaly
    — Associated syndromes – Crouzon and Goldenhar and Treacher Collins and Pierre Robin

Radiology Cases of First Branchial Cleft Cyst

CT and MRI of first branchial cleft cyst
Axial CT with contrast of the face (above) shows a low density, poorly circumscribed lesion with faint rim enhancement expanding the right parotid gland. Inflammatory changes are noted in the adjacent subcutaneous tissues. Axial T2 MRI of the face from 7 months later (below left) shows areas of oval high signal intensity weaving in and out of the plane of the image representing a tract from the posterior aspect of the right parotid gland to the right external auditory canal which on axial DWI MRI (below right) also shows high signal intensity representing diffusion restriction in the tract.