Intramural squamous cell carcinoma of the esophagus.

A case of squamous cell carcinoma arising from an esophageal intramural squamous epithelial cyst is reported. Review of the literature reveals no previous reports of malignant transformation of esophageal cysts, although there have been reports of approximately 64 cases of benign esophageal cysts, and 35 cases of carcinoma arising in esophageal diverticula. In the present case, there was a history of increasing dysphagia for 2 months. Esophagram demonstrated a 4.5-cm concentric narrowing of the proximal esophagus just below the superior esophageal ring. Esophagoscopies revealed an esophageal stricture with intact mucosa, and bronchoscopy showed the lesion to be producing tracheal deviation. Multiple esophageal biopsies revealed mild mucosal hyperplasia with deep submucosal inflammatory changes suggesting an underlying lesion. Despite lack of histologic proof of malignancy, the patient underwent radiation therapy and bleomycin chemotherapy on the basis of the highly suggestive radiographic findings, but died with bilateral bronchopneumonia 6 months after admission. Autopsy demonstrated a 1.5-cm long intramural esophageal squamous epithelial cyst, from which arose a locally invasive squamous cell carcinoma, without mucosal involvement or metastases. There was no demonstrable evidence of any associated esophageal diverticulum.