Dacryocele (dacryocystocele) is a condition in which the lacrimal sac dilates and forms a cyst as a result of congenital nasolacrimal duct obstruction (NLDO). It is also called lacrimal sac cyst, amniotocele, or mucocele. It corresponds to Q10.5 in the ICD-10 classification.
The incidence is about 3% of children with congenital nasolacrimal duct obstruction, ranging from 1.25% to 12.5% depending on reports 1). 91% are unilateral, and up to 30% are bilateral 1). 23% of cases require surgical intervention 1).
Congenital nasolacrimal duct obstruction occurs when the lower part of the nasolacrimal duct fails to open at 8 months of gestation. The spontaneous resolution rate is about 70% at 3 months, about 80% at 6 months, and 80–100% at 12 months of age. The main symptoms of congenital nasolacrimal duct obstruction are tearing and discharge from birth.
Bluish-purple swelling of the inner canthus: A bluish swelling appears at or slightly below the inner canthus on the nasal side at birth or within a few days after birth.
Mucopurulent discharge: Eye discharge and eyelash adhesion upon waking are observed.
Epiphora: Persistent overflow of tears (epiphora) occurs.
Respiratory distress: Bilateral large intranasal cysts may cause respiratory difficulty during feeding; severe cases can lead to acute respiratory distress.
Cystic mass: A bluish cystic mass is palpable below the medial canthal tendon in the nasolacrimal duct area.
Upward displacement of the medial canthus: The mass may cause upward displacement of the medial canthus.
Compression discharge: When the mass is compressed, mucopurulent discharge is expressed from the punctum.
Intranasal extension: The nasal mucosa expands and extends into the nasal cavity. It is confirmed as a cyst under the inferior turbinate on nasal endoscopy.
Atypical cases: Bluish-purple swelling may not be the initial symptom1). Even if the patient presents only with epiphora, CT and endoscopic examination should be considered.
The underlying cause of dacryocystocele is congenital obstruction of the distal nasolacrimal duct (membranous portion).
Closure of Hasner’s valve: Closure of Hasner’s valve at the nasal opening of the nasolacrimal duct causes the duct to become sac-like.
Fluid entrapment: Mucus from lacrimal sac goblet cells and amniotic fluid become enclosed within the nasolacrimal duct. Dissolved mesoderm, mucus, amniotic fluid, tears, and bacterial colonization contribute to swelling1).
Two-way obstruction: Dilation of the lacrimal sac causes bending and closure of the common canaliculus entrance. Rosenmüller’s valve acts as a one-way valve proximally, limiting reflux.
Since it is caused by congenital anatomical abnormalities of the lacrimal duct (closure of Hasner’s valve), there are no specific preventive measures. Early detection after birth and appropriate management (lacrimal sac massage and infection prevention) are important.
Clinical examination is fundamental. Check whether fluid is expelled from the punctum by digital massage of the lacrimal sac. In lacrimal irrigation, complete reflux of saline confirms obstruction.
Ultrasound: B-scan can show a hollow circular cavity. A-scan shows high-reflectivity walls and low internal reflectivity. It is noninvasive and useful for differentiation from other diseases1).
Nasal endoscopy: Evaluates the presence of intranasal cysts and confirms the impact on breathing.
CT/MRI: Visualizes a cystic mass extending from the lacrimal system to the inferior meatus. Not mandatory but useful when intranasal cysts are present or in atypical cases1).
Lacrimal sac massage: Gently massage the area between the inner canthus and the nasal root (lacrimal sac area) and the nasal ala. Pressure on the lacrimal sac promotes opening of the obstructed area 1).
Prophylactic antibiotic eye drops: Use antibiotic eye drops concurrently to prevent infection 1).
Expectation of spontaneous opening: Congenital lacrimal sac hernia often resolves spontaneously, and spontaneous opening is possible until around 6 months of age.
Indications: If conservative treatment does not improve within 1–2 weeks after birth, or if signs of infection (acute dacryocystitis) appear.
Probing
Nasolacrimal duct probing: The obstruction is perforated with a metal probe. Probing is recommended after 6 months of age from the perspective of infant immunity. If there is significant pus accumulation, it may be performed at 4–6 months. Complete cure is not achieved in about 25% of cases.
Endoscopic surgery
Endoscopic nasal cyst marsupialization: The success rate of intranasal cyst marsupialization combined with nasolacrimal duct probing is over 95%. Using a nasal endoscope to break the cyst wall with forceps from within the nasal cavity is effective. This can be performed at the bedside by a pediatric otolaryngologist. In some cases, symptoms resolve the day after surgery1).
Acute respiratory distress: Emergency endoscopic nasal cyst removal is required.
QCan a dacryocystocele resolve without surgery?
A
Conservative management (dacryocyst massage plus prophylactic antibiotic eye drops) may lead to improvement, and spontaneous resolution is possible until around 6 months of age. However, if no improvement occurs or signs of infection appear, prompt surgical intervention is necessary. The success rate of endoscopic intranasal cyst marsupialization is reported to be over 95%.
The development of a dacryocystocele begins with congenital obstruction of the lower nasolacrimal duct opening (persistence of Hasner’s valve).
Fluid entrapment: Mucus secreted by goblet cells of the lacrimal sac and amniotic fluid are trapped due to distal obstruction.
Fluid accumulation via a two-valve mechanism: Rosenmüller’s valve (proximal) acts as a one-way valve limiting reflux, and together with obstruction of Hasner’s valve (distal), fluid accumulates and distends the lacrimal sac.
Compression of the common canaliculus: Dilation of the lacrimal sac bends and closes the common canaliculus opening, completely obstructing the outflow of fluid.
The anatomical measurements of the lacrimal drainage system are shown below.
Site
Measurement
Lacrimal sac height
9.8–11.0 mm
Anteroposterior diameter of the lacrimal sac
7.5 mm
Length of the nasolacrimal duct
15–18 mm (bony portion 12 mm)
The lacrimal sac wall contains a cavernous structure and lacrimal drainage-associated lymphoid tissue (immune system). The bony entrance of the nasolacrimal duct is funnel-shaped, with a high incidence of obstruction.
