Composite Tumor with Papillary Adenocarcinoma and Squamous Cell Carcinoma of the Esophagus: Report of a Case

Abstract: Papillary adenocarcinoma is extremely rare in the squamous epithelium-lined esophagus. The histopathologic and immunohistochemical characteristics were examined in a composite tumor showing distinct papillary adenocarcinoma and squamous cell carcinoma of the esophagus resected from a 66-year-old man. The esophageal tumor consisted both grossly and histologically of two distinct components: an ulcerative part showing a squamous cell carcinoma, and a polypoid part corresponding to a papillary adenocarcinoma. In addition, the in situ squamous cell carcinoma was contiguous with the esophageal tumor. Mucin secretion was found only in the papillary adenocarcinoma component. Immunohistochemically, tumor cells of the papillary adenocarci-noma component were positive for carcinoembryonic antigen, secretory component, and lactoferrin. These staining patterns were similar to those of the normal esophageal gland proper. These histologic, mucin-histochemical, and immunohistochemical findings suggest that the papillary adenocarcinoma originated from the submucosal esophageal gland and the squamous cell carcinoma from the squamous epithelium lining the esophagus.