Primary malignant melanoma of the esophagus: a case report with endoscopic and electron microscopic studies.

Primary malignant melanoma of the esophagus (PMME) is a malignant tumor which occurs in the melanin cells of esophageal mucosal epithelial basal layer. PMME is a rare disease with an extremely poor prognosis. PMME represents only 0.1% to 0.2% of all esophageal malignant tumors. Dysphagia, retrosternal or epigastric discomfort or pain is the most frequent symptom at presentation. Retrosternal, epigastric discomfort, melena or hematemesis are the major clinical manifestations. The tumor is often located from the middle to lower thoracic esophagus. The characteristic endoscopic finding of PMME is a polypoid lesion that is usually pigmented. Immunohistochemical examination with positive results of S100 protein, HMB45 and neuron-specific enolase allow a definitive diagnosis. PMME metastasizes via hematogenic and lymphatic pathways. Esophagectomy is believed to be an effective approach for localized PMME. Five-year survival rates of 37% or higher have been achieved recently. Herein, we report a case of an 65-year-old female admitted for progressive difficulty in swallowing for more than 4 mo. After upper gastrointestinal endoscopy and biopsy, upper gastrointestinal series and computed tomography examination, the patient accepted radical esophagectomy, and the postoperative pathologic and immunohistochemical examination showed PMME.