Diagnosis:
Esophagus biopsy: Granular cell tumor

Comment:
Granular cytoplasm and bland nuclei are typical of this tumor. The pronounced pseudoepitheliomatous hyperplasia is characteristic of granular cell tumors and has led to a misdiagnosis of squamous cell carcinoma. The esophagus and anus are the most frequent sites of this tumor in the GI tract. They are virtually always benign and are S-100 positive.