Esophageal parakeratosis mimicking endoscopic appearance of superficial esophageal neoplastic lesion such as dysplasia

Abstract

The endoscopic findings of esophageal parakeratosis have not been well defined and its clinical significance including malignant potential is unclear. Here, we report a case of esophageal parakeratosis presenting as a discrete flat elevated lesion and mimicking the endoscopic appearance of superficial esophageal neoplastic lesion such as dysplasia or cancer. A 72-year-old woman was referred to our hospital for an esophageal lesion detected by upper endoscopy during a medical check-up. Upper endoscopy revealed a 5-cm sized whitish flat elevated lesion involving the mucosa of the middle esophagus. The surface of this lesion showed mild nodularity and the margin was discrete. When spraying with lugol solution, the lesion was not stained. On microscopic examination, esophageal parakeratosis was noted on the luminal surface with a hyaline eosinophilic cytoplasm and small elongate nuclei oriented parallel to the surface. Although pathological examination of initial biopsy specimens revealed no evidence of neoplasia or infection, we carried out follow-up upper endoscopies 1 month and 1 year later because of endoscopic findings mimicking dysplasia or cancer. Endoscopic and histopathological findings from the first and the second follow-up upper endoscopies were same as those of the first examination and the final diagnosis of esophageal parakeratosis was made. Given the present case, esophageal parakeratosis needs to be considered as a differential diagnosis when a flat elevated lesion is found in the esophagus and biopsy specimens reveal no evidence of dysplasia or cancer.