Background
Lacrimal sac cysts are rare lesions in the lacrimal drainage system (LDS), originating from the lacrimal sac epithelium. Differentiating these cysts from other lacrimal sac masses is challenging due to limited existing knowledge. This study aims to summarize CT and CT-DCG imaging characteristics of lacrimal sac cysts, aiding clinical classification and differential diagnosis, and to statistically analyze anatomical changes in the LDS of these patients.
Methods
This retrospective case-control study was conducted at the ENT Hospital of Fudan University. Patients diagnosed with lacrimal sac cysts were included, excluding those with certain surgeries, fractures, trauma, or other lacrimal sac masses. Controls were patients with a normal nasolacrimal drainage system undergoing CT examinations for eyeball atrophy or an intraocular foreign body. Anatomical assessments included nasolacrimal duct (NLD) width, lacrimal sac fossa structures, and nasal abnormalities.
Results
The study included 60 participants (50 females, 10 males) with a mean age of 47.43 ± 13.60 years. CT and CT-DCG imaging demonstrated four primary patterns: contrast agent reflux with no enhancement in lachrymal sac, partial thin rim enhancement of cyst wall, fluid level, and cystic lumen with a fluid-filled lightbulb sign. The average distances from the middle turbinate axilla (MTA) to the upper and lower limits of the lacrimal sac fossa (LSF) were 3.34 ± 3.37 mm and 11.00 ± 4.40 mm, respectively. Patients with lacrimal sac cysts exhibited widening of the lacrimal sac fossa, thinner frontal process thickness, and a larger lacrimal bone angle compared to controls, indicating bone remodeling due to the cysts.
Conclusions
Radiological imaging and detailed anatomical evaluations are crucial in diagnosing and managing lacrimal sac cysts. Identifying specific radiological patterns and anatomical changes improves diagnostic accuracy and surgical planning.
