Abstract
There have been only a few reports concerning the cytology of epithelioid sarcoma. We describe a typical case of a 29-year-old male. He had the primary tumor in the subcutaneous tissue of the left forearm eight years previously, and thereafter, multifocally in the extremities and body. Histologically, tumor cells contained atypical nuclei and abundant eosinophilic cytoplasm, and proliferated in a sheet or trabecular pattern with a central necrotic focus and surrounding intense fibrosis. Ultrastructurally, tumor cells contained euchromatin-rich irregular-shaped nuclei with prominent nucleoli, and many intermediate filaments running irregularly throughout the cytoplasm. A few microvilli and pinocytotic vesicles were present, but neither obvious basal laminae nor junctional complexes were detected.
In the imprint cytology, tumor cells were round or polygonal in shape, containing round nuclei with a somewhat delicate nuclear margin, granular chromatin and one or two conspicuous nucleolei, and possessed broad clear or deeply stained cytoplasm. Mitotic figures were occasionally found.Tumor cells were positive for keratin, vimentin and EMA, and negative for S-100 protein. Therefore, it is considered possible to distinguish the epithelioid sarcoma from other tumors based on the above characteristics.
