CHORDOMAS - PATHOLOGICAL FEATURES - PLOIDY AND SILVER NUCLEOLAR ORGANIZING REGION ANALYSIS - A STUDY OF 36 CASES

Chordomas are slow growing malignant neoplasms with a prolonged clinic al course which do not usually metastasize. They are histologically be nign, locally invasive and often recur following resection. Survival h as been shown to vary widely and prognostic indicators have been diffi cult to identify. Cellularity, mitotic activity and cellular pleomorph ism have not been found to have prognostic significance. Thirty-six ca ses of clival, cervico-thoracic and sacral chordomas were evaluated ut ilizing four variables as possible predictors of survival: (1) silver nucleolar organizing region (AgNOR), (2) ploidy, (3) fibrosis , and (4 ) inflammatory response. AgNOR areas in approximately 200 cells per ca se were calculated and summed. DNA ploidy was obtained in 23 of the ca ses by analyzing deparaffinized Feulgen-stained tissue. Fibrosis and i nflammation were evaluated by hematoxylin and eosin and by trichrome s tains. Clinical follow-up was available in the 36 cases with survival ranging from 0.5 to 159 months. A statistical analysis employing the C ox-Proportional Hazards model disclosed no significant correlation bet ween AgNOR area and clinical outcome (P > 0.05). The variables, fibros is, and inflammation, did not demonstrate prognostic significance (P > 0.05). Ploidy demonstrated a statistical trend for prognostic signifi cance (P = 0.077). It is apparent that three of the four parameters st udied do not independently affect survival. Although AgNOR has proved useful in the study of other neoplasms such as those of breast, prosta te and bladder, it is not of significant importance in predicting the behaviour of chordomas. Ploidy, on the other hand, may be of value in predicting clinical outcome in chordomas and may be a useful marker in the evaluation of the aggressive biological behavior of these neoplas ms.