Role of the argyrophilic nucleolar organizer regions in tumor detection and prognosis.

The expression of the argyrophilic nucleolar organizer regions (AgNORs) has been analyzed in renal, bladder, and pharyngeal carcinomas, multiple myeloma (MM), and skin melanocytic lesions to clarify their role in tumor detection and prognosis. Sections from formalin-fixed, paraffin-embedded biopsies were stained with the method of Ploton; the mean AgNOR number per nucleus (AgNOR count) and their distribution (configuration) were assessed examining 100 neoplastic cells. AgNOR counts and histologic grade were highly associated in bladder urotheliomas (6.01 for grade 1 [G1], 7.69 for G2, 13.35 for G3; p < 0.00001) and MM (3.18 for G1, 4.36 for G2, 6.13 for G3; p < 0.0001); they were not associated in renal cell carcinomas (5.35 for G1, 5.92 for G2, 7.99 for G3; p = 0.132) and pharyngeal carcinomas (11.1 for G2, 10.27 for G3; p = 0.08). AgNOR number was also related to the degree of malignancy in melanocytic lesions (2.93 for common blue nevus, 2.89 for benign nevus [BN], 3.69 for cellular blue nevus [CBN], 7.71 for malignant melanoma, and 8.33 for malignant cellular blue nevus [MCBN]; p < 0.00001). Association between AgNOR counts and pathologic stage was found in bladder carcinomas (6.43 for pTa, 10.19 for pT1, 12.57 for pT2-4; p < 0.00001) and MM (3.06 for cases with percentage of bone marrow plasma cells [BMPC%] < or = 20, 4.28 for BMPC% 21 to 50, 5.14 for BMPC% > 50; p < 0.0001]; no correlation was found in pharyngeal (11.18 for T1, 10.08 for T2, 10.68 for T3, 11.47 for T4; p = 0.18) or renal cell carcinomas (6.06 for pT2, 6.31 for pT3; p = 0.78). Few, large and grouped AgNORs were found in well-differentiated bladder carcinomas, MM, and benign melanocytic lesions; numerous, small and dispersed AgNORs were seen in poorly differentiated bladder, renal and pharyngeal carcinomas, MM and malignant melanocytic lesions. Significant association with prognosis was found in pharyngeal carcinomas (5-year survival: 68% for cases with < or = 10.31 AgNOR/cell, 20% for cases with > 10.31 AgNORs) and MM (5-year survival: 46% for cases with < or = 4.62 AgNOR/cell, 7% for cases with > 4.62 AgNORs; in MM the configuration too was related to prognosis: median of survival 72 months for tightly grouped, 16 for partially grouped, and 11 for dispersed AgNORs). Our results indicate that AgNOR number and configuration are useful in detection and prognosis of some neoplasias. They permit a rapid evaluation of morphology and tumor cell kinetics even on small biopsies.(ABSTRACT TRUNCATED AT 400 WORDS)