Small cell carcinoma of the esophagus. Cytology and immunohistology in four cases.

Four cases of small cell carcinoma of the esophagus diagnosed by cytology, with subsequent histologic confirmation, were reviewed. The presence of small malignant cells in isolation with minimal cytoplasm was the common characteristic cytologic finding. Cellular molding was observed only focally in two cases, and streaking of nuclear material was not observed in any smear. The tumor cells were argyrophilic and not argentaffinic. Immunohistochemically the neoplastic cells were consistently immunoreactive with low-molecular-weight cytokeratins and epithelial membrane antigen. Esophageal washings as well as endoscopic biopsies yielded diagnostic material in all cases, but the histologic material was remarkable for crush artifacts that hindered the microscopic interpretation.