Chordoma: cytologic and immunocytochemical study of four cases

We present the cytologic features and the immunocytochemical profile of four cases of chordoma on fine-needle aspiration biopsies. The physaliferous cells in signet-ring, pearl-like formations and the trabecular arrangement with rounded contours are distinctive. Other cell types and cellular arrangements are also described. The negative immunoreactivity of carcinoembryonic antigen (CEA) and the positive staining pattern for neuron-specific enolase (NSE), S-100 protein, epithelial membrane antigen (EMA), and keratin provide a profile that, in the appropriate clinical setting, can be useful in the differential diagnosis of chordoma from similar-appearing neoplasms in small biopsies and fine-needle aspirates.