About 10 years ago, this 63-year-old man noticed a lesion on his eyelid. It didn’t bother him, so he ignored it—until recently, when it reached a size sufficient to interfere with his vision. This development, and subsequent commentary from friends concerned by its proximity to his eye and fears of cancer, disturbed him enough to seek evaluation.
He first consulted an ophthalmologist, who provided a diagnosis that the patient promptly forgot. However, he was also advised to see a dermatologist or plastic surgeon for further evaluation, since the lesion does not affect the eye itself. The patient wants the lesion removed but seeks a dermatology referral first.
He denies pain, discomfort, or trauma to the affected area.
A translucent, round, 7-mm cystic lesion is located on the left lateral lower eyelid just below the margin, resembling a bleb. No redness is seen in the area. Palpation confirms the soft, cystic nature of the lesion.
Examination of the other eye and the rest of the patient’s facial skin reveals no abnormalities.
What is the diagnosis?