USEFULNESS OF ARGYROPHILIC NUCLEOLAR ORGANIZER STAINING FOR HISTOLOGIC GRADING OF SOFT-TISSUE SARCOMAS

Accurate histologic grading is essential for making a proper therapy d ecision in soft-tissue sarcomas (STS). The usefulness of the argyrophi lic stain for nucleolar organizer region (AgNOR) in assessing the hist ologic grade of STS has been examined. One hundred and forty-two patie nts with STS confined to the extremity and trunk were selected. Tumors were classified based on the criteria of Enzinger and Weiss [''Soft-T issue Tumors.'' St. Louis: C.V. Mosby, 1983]. In addition, non-specifi c classification was made based on the shape of proliferating cells oc cupying more than 50% of the field in the sections such as pleomorphic cell, small round cell, spindle cell, epithelioid cell, myxoid, and u nclassified tumors. The mean number of AgNOR dots per nucleus of tumor cells was calculated in 200 cells (AgNOR count). Each category of non -specific classification was divided into a high-count group (<8 AgNOR count) and a low-count group (>8 NOR). The low-count group showed a s ignificantly better prognosis than the high-count group in small round cell and spindle cell tumors (P<0.007 and P<0.0005, respectively). Si milar results were obtained in pleomorphic cell tumors, though they we re statistically not significant because of the relatively small numbe r of examined cases. Most patients with epithelioid cell and myxoid tu mors were in the low-count group. These findings suggest that the asse ssment of histologic grading of STS could be made effectively by the n on-specific classification and the aid of AgNOR staining. (C) 1993 Wil ey-Liss, Inc.