A case of verrucous carcinoma of the esophagus associated with difficult histopathological diagnosis of endoscopic biopsy specimens

Verrucous carcinoma of the esophagus (VCE) is a rare, slow-growing, well-differentiated squamous cell carcinoma. Histologically, superficial layers of this cancer tend to have less atypical epithelium with non-specific inflammatory change, which therefore makes diagnosis of malignancy extremely difficult unless a surgical specimen is obtained. We recently encountered a case in which a malignant tumor was suspected on initial endoscopic evaluation, but two biopsies revealed no carcinoma cells. Analysis of a third biopsy finally suggested the possibility of squamous cell carcinoma. A subsequent surgical specimen revealed the tumor as VCE. In addition, immunohistochemical examination revealed that Ki67 immunopositive cells were distributed along the basal layer of the VCE, regarded as a pattern unique to this type of cancer. It is important to know of the existence of VCE. In cases in which this tumor is endoscopically suspected, repeated deep biopsy is strongly recommended and the only curative treatment for this type of cancer is resection.