Computed tomography and computed tomography dacryocystography imaging characteristics of lacrimal sac cysts in adults: a retrospective study.

BACKGROUND

Lacrimal sac cysts (LSCs) are rare lacrimal drainage system (LDS) lesions that often present as medial canthal masses or epiphoras in adults. Computed tomography (CT) and computed tomography dacryocystography (CT-DCG) can aid in the diagnosis of LDS; however, the literature is limited to case reports and adult systematic studies, and discriminative imaging pattern and LDS anatomical change analyses are lacking, hindering treatment. Thus, this study sought to analyze the CT/CT-DCG features and LDS anatomy of adults to address these gaps in the literature.

METHODS

This single-center retrospective case-control study included patients diagnosed with LSCs at the Eye & ENT Hospital of Fudan University. Patients with a history of prior surgeries, trauma, tumors, or thyroid-associated ophthalmopathy were excluded from the study. The control subjects comprised individuals with normal LDS undergoing CT for unrelated conditions. CT and CT-DCG imaging were analyzed for radiological patterns, while the anatomical measurements included the nasolacrimal duct (NLD) width, lacrimal sac fossa (LSF) dimensions, and nasal abnormalities.

RESULTS

A total of 60 participants (50 females, 10 males; mean age: 47.43±13.60 years) were included in the study. CT and CT-DCG imaging revealed four distinct patterns: contrast agent reflux without enhancement, partial thin rim enhancement of the cyst wall, fluid level, and a fluid-filled lightbulb sign. The patients with LSCs exhibited a widened LSF, a thinner frontal process, and larger lacrimal bone angles than the controls, indicating bone remodeling. The average distance from the middle turbinate axilla (MTA) to the upper and lower limits of the LSF were 3.34±3.37 and 11.00±4.40 mm, respectively.

CONCLUSIONS

CT and CT-DCG imaging are critical in the diagnosis LSCs; specific patterns and anatomical changes can enhance diagnostic accuracy and guide surgical planning. These findings provide vital insights into the clinical management of LSCs, particularly in relation to dacryocystorhinostomy procedures.