Argyrophilic Nucleolar Organizer Regions in Recurrent Lipomatous Tumors

Abstract

To analyze the proliferation rate in liposarcomas, we studied two silver staining nucleo lar organizing region (AgNOR) counts in a series of 18 patients with multiple recur rences. In a retrospective analysis of corresponding primary and recurrent tumors, cell nuclear characteristics were assessed by the mean number of AgNORs and the percent age of nuclei with more than five AgNORs per nucleus. The computer-assisted analysis of AgNORs compared with clinicopathologic data showed that two AgNOR counts varied considerably in primary lipomatous tumors and in subsequent recurrences along the course of disease. In most patients, proliferative activity of recurrent tumors varied randomly, without any consistent pattern, except in some liposarcomas that showed transformation to a more aggressive histologic picture. In individual patients, decrease in both AgNOR counts paralleled the prolongation of the recurrence-free interval and vice versa. In this limited series, the AgNOR counts did not prove to be an independent prognostic factor in patients with liposarcoma. Int J Surg Pathol 1 (4) :245-252, 1994