BENIGN SCHWANNOMA OF THE ESOPHAGUS - REPORT OF 2 CASES WITH IMMUNOHISTOCHEMICAL AND ULTRASTRUCTURAL STUDIES

Two cases of benign schwannoma of the esophagus are presented. The tum ors were found in the thoracic esophagus of women of 56 and 64 years o f age, respectively, who had complained of dysphagia and back pain. Tu morectomies were performed and the tumors were found to be located wit hin the esophageal wall arising from the muscularis propria. The tumor s were examined immunohistochemically and ultrastructurally. These tum ors were identical in gross, histological and electron microscopic fea tures. Grossly, the tumors showed yellowish-white cut surfaces without hemorrhage or necrosis. Microscopically, they were composed of spindl e-shaped cells showing moderate variation in size and shape, and nucle ar palisading. Lymphoid aggregates with germinal centers surrounded th e tumors. Immunohistochemically, strong reactions for S-100 protein an d neuron-specific enolase were observed in the cytoplasm of spindle ce lls, whereas reactions for muscle actin and desmin were negative. Thes e findings, together with electron microscopic observations, supported the Schwann cell origin of these tumors.