Background: High-frequency ultrasound has improved our ability to manage and diagnose anterior segment tumors. Hidrocystomas are unusual cystic tumors that can affect the conjunctiva and eyelid. When they appear pigmented and rapid in onset, it is important to differentiate them from malignant tumors, such as melanoma.
Case reports: Three patients were referred to The New York Eye Cancer Center for evaluation of pigmented lesions on their eyes. The tumors affected the conjunctiva or eyelid and were of recent onset ranging from 1 week to 6 months. The hidrocystomas displayed hypoechoic high-frequency ultrasound patterns, which corresponded to the cystic nature revealed through histopathological analysis. Differential diagnoses are discussed and include benign and malignant tumors.
Conclusion: Cystic tumors are a common finding of the eye; however, pigmented hidrocystoma is an uncommon diagnosis. Although histopathological study is often required for definitive diagnosis of these lesions, much information can be gained through pre-surgical evaluation, particularly high-frequency ultrasound. Intra-lesional cyst formation was characteristic in these three tumors. Further study of the high-frequency ultrasound characteristics of pigmented eyelid and conjunctival tumors will help determine if these ultrasound characteristics are diagnostic.