Intratarsal Keratinous Cysts of the Meibomian Gland: Distinctive Clinicopathologic and Immunohistochemical Features in 6 Cases

Abstract

To describe 6 patients representing a new entity of Meibomian gland keratinous cysts. Retrospective, interventional, clinicopathologic study. Review of clinical histories and findings, histopathologic evaluations, and immunohistochemical studies of the cysts' linings with monoclonal antibodies directed against cytokeratins and cell surface epithelial markers. Six patients with an average age of 62.5 years had noninflamed, upper eyelid nodules fixed to the tarsus. Eyelid eversion revealed a white-yellow nodular bulge in 3 cases, a bluish coloration in 2 cases, and a translucent appearance in 1 case. The cysts were lined by undulating squamous epithelium possessing an inner eosinophilic cuticle that produced a peculiar refractile, strand-like intracavitary keratin. Immunostaining for cytokeratin 17 and carcinoembryonic antigen showed strongly positive results in the Meibomian gland cysts and, by comparison, negative results in cutaneous epidermal cysts. Multiple recurrences occurred after incomplete excisions. After chalazia and sebaceous cell tumors, Meibomian gland keratinous cysts seem to be the third most common primary intratarsal lesion. Anterior fixation to the tarsus and posterior protrusion beneath the palpebral conjunctiva without inflammation suggest the diagnosis. Histopathologic and immunohistochemical evaluations can distinguish unequivocally the current entity from common epidermal cysts. The optimal treatment consists of an en bloc excision of the cyst with a tarsectomy, or else wide excision with intratarsal cautery of any remnants of the cellular lining.