Development of Epidermoid Metaplasia of the Mucosa in Association with Esophageal Intramural Pseudodiverticulosis and Candidiasis

We report a case of epidermoid metaplasia of the esophageal mucosa that developed in a patient with a long history of esophageal intramural pseudodiverticulosis (EIPD) complicated by candidiasis. The patient, a 69-year-old man, had been treated for about 3 years for EIPD with candidiasis. After candidiasis improved, the development of epidermoid metaplasia of the esophageal mucosa was observed. It comprised longitudinally arranged, multiple, small, whitish flecks with a scaly appearance on the mucosa of the middle to lower esophagus, and pathological examination demonstrated several fine keratohyalin granules in superficial layers of the squamous epithelium. Six months later, candidiasis was almost cured, but these small flecks had slightly increased in size, and pathological examination demonstrated epidermoid metaplasia consisting of a thick, acellular keratin layer and well-developed granular layer beneath it. We considered that chronic candida esophagitis played the principal pathogenetic role in the development of epidermoid metaplasia. EIPD may have provided an environment suitable for the growth of fungi, and mucinous material contaminated by Candida and excreted from the orifices of EIPD may have irritated the mucosa and induced epidermoid metaplasia.