Clinicopathologic characteristics and histogenesis of primary malignant melanoma of the esophagus

Objective To investigate the diagnosis,differential diagnosis,histogenesis and biologic behaviors of primary malignant melanoma of the esophagus.Methods Two cases of primary malignant melanoma of the esophagus were studied with clinicopathological analysis,histopathological analysis and immunohistochemistry,and literature review.Results Primary malignant melanoma of the esophagus was often seen in middle and old persons.The tumors were usually located in the distal third of the thoracic esophagus.The patients presented with dysphagia,and glossly,the tumor tended to be polypoid.The expression of the HMB 45 and S 100 antigen was positive.Conclusion When a polypoid mass of the esophagus occurs in middle or old persons,the possibility of primary malignant melanoma of the esophagus should be considered.Immunohistochemical stain and electron microscopy are helpful in the definite diagnosis,and histogenesis of the tumor may originate from melanocytes of esophagus.