DECISIVE ROLE OF IMMUNOCYTOCHEMISTRY IN ASPIRATION CYTOLOGY OF CHORDOMA OF THE CLIVUS - A CASE-REPORT WITH REVIEW OF THE LITERATURE

Immunocytochemistry (ICC) proved to be an essential adjunct in the fin e-needle aspiration (FNA) cytological diagnosis of chordoma of the cli vus in a 62-year-old woman. The cytological picture in routinely stain ed smears was not entirely diagnostic for chordoma due to the paucity of typical 'physalipherous' cells. To exclude other primary or metasta tic neoplasms of the skull base possibly sharing the same cytological picture, additional direct smears were immunostained with antibodies s pecific for cytokeratin (CK), vimentin (VIM), S100 protein (S100P), ca rcinoembrionic antigen (CEA), epithelial membrane antigen (EMA), glial fibrillary acidic protein (GFAP), CD68 antigen (KPI) and with the 'pa nepithelial' antibodies B72.3 and Ber-EP4. Chordoma cells showed the f ollowing immunoprofile: VIM+/S100P+/CEA-/EMA+/GFAP-/B72.3-/Ber-EP4-/CD 68+. The pattern of immunoreactivity for CK, S100P and CEA confirms pr eviously reported data, while the B72.3-/Ber-EP4-/CD68+ staining profi le represents a novel observation. The detection of a CK/S100+/CEA-/B7 2.3-/Ber-EP4- immunocytological profile of chordoma cells in aspirates is a basic requirement to exclude pertinent diagnostic differentials, such as metastatic carcinoma, ependymoma and sarcoma, and permits a r eliable pre-operative diagnosis of the tumour by aspiration cytology.