Composite tumor with papillary adenocarcinoma and squamous cell carcinoma of the esophagus: Report of a case

Papillary adenocarcinoma is extremely rare in the squamous epithelium-lined esophagus. The histopathologic and immunohistochemical characteristics wer e examined in a composite tumor showing distinct papillary adenocarcinoma a nd squamous cell carcinoma of the esophagus resected from a 66-year-old man . The esophageal tumor consisted both grossly and histologically of two dis tinct 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 tumo r. Mucin secretion was found only in the papillary adenocarcinoma component , Immunohistochemically, tumor cells of the papillary adenocarcinoma compon ent were positive for carcinoembryonic antigen, secretory component, and la ctoferrin. These staining patterns were similar to those of the normal esop hageal gland proper. These histologic, mucin-histochemical, and immunohisto chemical findings suggest that the papillary adenocarcinoma originated from the submucosal esophageal gland and the squamous cell carcinoma from the s quamous epithelium lining the esophagus.