Clinicopathological studies of esophageal carcinoma in achalasia: Analysesof carcinogenesis using histological and immunohistochemical procedures

Achalasia of the esophagus is a benign disease caused by dyskinesia of the lower esophagus and cardia and is presumed to be a premalignant lesion lead ing to an increased risk of squamous cell carcinoma. We analyzed six surgic ally or endoscopically resected carcinomas among 54 cases of esophageal ach alasia using histological and immunohistochemical procedures. The mean inte rval between the diagnosis of achalasia and carcinoma was 21.5 years. Four of the six cases were superficial early-stage cancers whilst the other two were advanced cancers invading the adventitia. Histological mapping of the resected esophageal specimens demonstrated mal ked hyperplastic changes of stratified squamous epithelium and multiple foci of dysplastic changes. The squamous cell carcinomas showed well-differentiated type with low-grade at ypia, closely associated with dysplastic foci. Immunohistochemical staining for p53, p21, p16 and epidermal growth factor receptor suggested that the dysplastic epithelium was a borderline lesion between hyperplasia and in si tu carcinoma. Our observations suggested that esophageal food stasis induce s chronic hyperplastic esophagitis and eventually malignant transformation of esophageal epithelial cells, associated with dysplasia-carcinoma sequenc e.