Intratarsal epidermal inclusion cyst.

Abstract To report 3 cases of epidermal inclusion cyst that arose within the tarsus, an unusual site of origin. A retrospective review of medical records of patients undergoing excision of eyelid epidermal inclusion cysts by one surgeon (MJL) over a decade revealed 3 cases of intratarsal epidermal inclusion cyst. Initially, these lesions resembled chalazia and were first addressed with incision and curettage. There was recurrence of the cyst in all the 3 cases from 1 to 4 months, and subsequent complete excision was necessary. At surgery in each of these cases a cyst arising within the tarsus was encountered. Eventually, the tarsus containing the base of the cyst was excised to ensure complete removal. The cysts were approximately 8 mm to 10 mm in greatest dimension and had yellowish-white gelatinous contents. Histopathologic evaluation revealed keratin-filled cysts arising from tarsus and lined by stratified keratinized epithelium. In one of the cases the tarsal tissue around the cyst wall showed epidermal elements presumably derived from sebaceous gland. There have been no recurrences after complete excision (follow-up range, 9-60 months). Intratarsal epidermal inclusion cysts share some clinical features with chalazia. Lack of inflammation, lack of fluctuation in size, gradual continued slow growth, and delayed onset of recurrence may help to differentiate tarsal cyst from recurrent chalazion. Incision and curettage, however, is not effective long-term treatment for this entity. Total excision of the cyst including full-thickness excision of tarsus at the cyst's base of origin is suggested for definitive treatment.