ASSESSMENT OF CELLULAR PROLIFERATION OF ECCRINE ACROSPIROMAS AND ECCRINE SWEAT GLAND CARCINOMAS BY AGNOR COUNTING AND IMMUNOHISTOCHEMICAL DEMONSTRATION OF PROLIFERATING CELL NUCLEAR ANTIGEN (PCNA) AND KI-67

Argyrophil nucleolar organizer regions (AgNORs) were counted and immun ostaining using antibodies raised against proliferating cell nuclear a ntigen (PCNA) and Ki-67 was carried out on eccrine acrospiroma and ecc rine sweat gland carcinoma, to determine the malignant potential and p rognosis of these tumours. Formalin-fixed and paraffin-embedded tissue specimens surgically excised from 25 patients with eccrine sweat glan d carcinoma (20 cases of eccrine porocarcinoma, four cases of ductal s weat gland carcinoma and one case of malignant clear cell hidradenoma) and 25 patients with eccrine acrospiroma (16 cases of eccrine poroma, four cases of poroid hidradenoma and five cases of clear cell hidrade noma) were used. PCNA and Ki-67 labelling indices were categorized sem iquantitatively into four grades. Significant differences were noted b etween eccrine sweat gland carcinoma and eccrine acrospiroma with thes e three methods (P < 0.01). When a cut-off of 5 was chosen, the AgNOR value distinguished eccrine sweat gland carcinoma from eccrine acrospi roma with high specificity and sensitivity. Moreover, we compared the results of these three methods between stages 1 or 2 (17 cases) and st age 3 (eight cases) eccrine sweat gland carcinomas, and no significant differences were observed. From these findings, these three methods a re useful in discriminating malignant from benign lesions of eccrine t umours, but have no value in estimating the aggressiveness of eccrine sweat gland carcinomas.