A Case of Congenital Lacrimal Sac Diverticulum

Purpose: We report the diagnosis and conservative treatment of a patient with dacryocystitis accompanied by a congenital lacrimal sac diverticulum.Case summary: An 11-year-old boy presented with itching and redness in his right eye. His best-corrected visual acuity was 0.8 in the right eye and 1.2 in the left. Physical examination revealed redness, swelling, and tenderness around the right lacrimal sac area. Probing of the nasolacrimal duct showed no obstruction. Additional tests were performed under the diagnosis of acute dacryocystitis. Computed tomography and magnetic resonance imaging suggested inflammation of the soft tissue with abscess formation around the right orbit, with inflammation extending to the lower eyelid. After 7 days of inpatient treatment, the symptoms improved. Dacryocystography performed after the symptoms improved showed a small amount of residual contrast in a space near the lacrimal sac, leading to the diagnosis of a right lacrimal sac diverticulum.Conclusions: In patients with dacryocystitis without nasolacrimal duct obstruction, congenital lacrimal diverticulum should be suspected.