Primary undifferentiated small cell carcinoma of the esophagus-A case report

Abstract

An unusual case of primary anaplastic small cell carcinoma of the esophagus is reported in a 50-year-old Japanese female. The morphological features observed are presented here and differential diagnosis among small cell carcinoma and other kind of carcinomas and histogenesis of esophageal small cell carcinoma are discussed. Grossly, the lesion showed an ulcerative tumor with a protruding portion in the middle part of the esophagus. Cytological smears revealed small mononuclear anaplastic cells occurring singly or in clusters. The tumor cells had small hyperchromatic round nuclei with no prominent or only slightly prominent nucleoli and scanty cytoplasm. The Indian-file appearance that is occasionally recognizable in the smears obtained from small cell carcinoma of the lung was also observed in the present case. Some tumor cells suggesting poorly differentiated squamous cell carcinoma were found in these smears. Histological examination of the resected esophagus showed that small tumor cell infiltration was confined to the tunica muscularis propria. The Grimelius method revealed a positive reaction in the tumor cells and NSE staining also demonstrated positive immunoreactivity in the cancer cell cytoplasm. The histopathological diagnosis was a primary small cell carcinoma of the esophagus.
Although, small cell carcinoma of the esophagus is rarely encountered, the cytological features mentioned above indicate that the tumor is a small cell carcinoma. Morphological findings suggest that this tumor originated from mucosal Kultzschisky cells or by dysdifferentiation of mucosal and/or glandular epithelial cells.