Ultrasound biomicroscopy of eyelid eccrine hidrocystoma

Case report: A 58-year-old white female noted a lesion on her left lower eyelid, present for 3 months. Examination disclosed a dark-blue, subepithelial, smooth mass along the cilia near the punctum. The lesion did not transmit light and was thought to be a solid mass, such as a deep-blue nevus or melanoma versus a cystic mass with internal debris. Ultrasound bionnicroscopy showed a fairly circumscribed echolucent mass measuring 3.2 x 3.5 mm suggestive of a cyst with numerous internal echo impedances. Following resection, histopathologic evaluation disclosed a cyst lined by a dual layer of eccrine sweat ductal epithelium, consistent with eccrine hidrocystoma. Comments: Eyelid hidrocystomas can be pigmented and can be confused clinically with melanocytic tumors. Ultrasound biomicroscopy can provide helpful diagnostic information about the internal architecture of such lesions.