[Sonographic diagnosis of congenital dacryocystocele].

AIM: Congenital obstruction of the nasolacrimal drainage system occurs quite commonly. The reason is usually an impaired canalization at the distal end of the nasolacrimal duct with a residual membrane between the duct and the nasal cavity. Dacryocystocele is believed to result from a concomitant upper and lower system obstruction, causing fluid accumulation and distension of the lacrimal sac. The patient presents at birth with a tense, blue-grey swelling located just below the medial canthal tendon. The differential diagnosis for dacryocystocele includes haemangioma, encephalocele, glioma, dermoid cysts and malignant processes.

MATERIAL AND METHODS: We demonstrate five typical cases to describe the sonographic features of dacryocystocele.

RESULTS: Ultrasound is a simple, straight forward and gentle method to reliably distinguish dacryocystoceles from other pathologies. A sedation of the patient is not necessary. The sonographic appearance of a cystic mass medial and inferior of the orbit communicating with the dilated nasolacrimal duct as well as the typical content of fluid and debris was diagnostic of a nasolacrimal mucocele or dacryocystocele. Other more invasive imaging techniques as CT-scans and MRI are of benefit only if there is any doubt about the diagnosis.