NASOLACRIMAL DUCT CYST

(Dacryocystocele; Lacrimal Duct Mucocele)

Dacryocystocele (lacrimal sac mucocele or amniocele) is defined as dilatation of the lacrimal drainage system from both proximal and distal obstruction of the nasolacrimal duct. The dilated sac fills with amniotic fluid and intrinsic mucoid secretion, causing it to distend and kink the canaliculi. This acts as a one way valve allowing fluid to only enter the sac.

• Congenital dacryostenosis - atresia of the distal Hasner valve.
• Dacryocystocele - functional obstruction at the orbital end of the lacrimal sac + atresia of the distal end of the nasolacrimal duct.

Embryology

Etiology / Pathogenesis

Ultrasound

Differential Diagnosis