Histology and ultrastructure of the human esophageal epithelium. I. Normal and parakeratotic epithelium.

The authors present a histological and ultrastructural analysis of normal and parakeratotic human esophageal epithelium. Parakeratosis is encountered frequently during routine examinations of noncancerous esophageal mucosa in patients with carcinoma of the esophagus. Morphologically, this alteration corresponds to an incomplete keratinization of the esophageal epithelium with an excessive accumulation of keratin microfilaments, nuclear maturation reaching the stages of pyknosis and lysis, and anomalies in surface cell desquamation.