Intratarsal keratinous cysts of the meibomian gland (a sebaceous duct cyst): report of 2 cases.

Intratarsal keratinous cyst of the meibomian gland is a recently described entity that recurs if not completely excised. Herein, we report 2 cases and discuss their diagnosis and management: (1) A 57-year-old man with a recurrent mass of the upper eyelid treated with incision and drainage as a chalazion for more than 5 years and (2) An 85-year-old man presented with a slow growing nodule of the upper eyelid. Exploration via the eyelid crease approach revealed cysts fixed to the tarsus that were completely excised with a portion of the anterior tarsus. Histologically, these cysts exhibited a keratinizing squamous epithelium without a granular layer (trichilemmal keratinization), were lined by an eosinophilic undulating cuticle, contain string-like keratin debris, and had a fibrous wall without sebaceous lobules. All epithelial components strongly expressed high-molecular weight keratins, whereas the lining, cuticle, and keratin contents strongly expressed carcinoembryonic antigen. No recurrence has occurred 7 and 12 months postoperatively. The location and clinicopathologic findings of intratarsal keratinous cysts distinguish it from sebaceous tumors, steatocystoma simplex, epidermoid cyst, and dermoid cyst. However, like steatocystomas, intratarsal keratinous cysts exhibit a sebaceous duct phenotype. The anterior lid crease approach with partial tarsectomy seems to be an effective treatment.