Silver-stained nucleolar organizer regions in the uterine myomatous tumors

Prognostic Value of Microvessel Density in Tumor and Peritumoral Area as Evaluated by CD31 Protein Expression and Argyrophilic Nucleolar Organizer Region Count in Endothelial Cells in Uterine Leiomyosarcoma

The objective of this study was to investigate the prognostic value of microvessel density (MVD) in uterine leiomyosarcoma (LMS) and peritumoral area (PA) as evaluated by CD31 expression and argyrophilic nucleolar organizer region (AgNOR) count in endothelial cells. Tissue specimens from 66 patients with uterine LMS were examined. There were no significant differences in the mean MVD between tumor itself and the PA (P = 0.9); moreover, the MVD in the PA often exceeded that in the tumor. No correlation or significant differences were also found in the MVD between different grades of malignancy of LMS (r = 0.1; P = 0.07). The number of AgNORs in tumor endothelial cells was significantly higher in tumor vessels than in the peritumoral area (P < 0.005) and increased with the tumor grade. Analysis of the prognostic value of MVD in uterine LMS and PA showed that the density of tumor vessels was not an independent criterion, while the MVD in the PA affected 10-year survival to a significantly greater extent (χ² = 27.5; P = 0.0003). The number of AgNORs also had an important effect on survival of LMS patients: when the threshold of 11.6 granules was exceeded, prognosis was significantly more unfavorable than that prior to exceeding the threshold.

A new scoring system using multiple immunohistochemical markers for diagnosis of uterine smooth muscle tumors

The diagnosis of uterine smooth muscle neoplasms by light microscopy is difficult. Multiple classification schemes have been proposed based on mitotic rate, nuclear atypia, and the presence or absence of necrosis. None of these classification systems has been entirely successful. This study was undertaken to evaluate the use of selected immunohistochemical and histochemical markers in differentiating these tumors, in addition to accepted morphologic criteria. Ten cases of each of the following: leiomyosarcomas (LMS), atypical leiomyomas (AL), cellular leiomyomas (CL) and usual leiomyomas (UL), were classically evaluated for histological diagnosis and were stained for Ki-67 (MIB-1), bcl-2 and p53 using monoclonal antibodies and the avidin-biotin peroxidase method, and argyrophilic nucleolar organizer region (AgNORs). The number of stained cells was counted in the most positively stained region in a 4 mm² square cover glass mounted on each slide. The mean value was calculated for each group of tumors. The data for Ki-67 (MIB-1), bcl-2, p53 and AgNOR staining respectively, were significantly higher in LMS by comparison to UL, CL or AL. Because many singular cases had superimposed data being difficult to diagnose, a new scoring system for pathological evaluation was created. The results obtained by this scoring system suggest that immunohistochemical markers Ki-67 (MIB-1), bcl-2, p53 together with the AgNOR staining could be useful, by the scoring system, as an adjunct to the current accepted morphologic criteria in differentiating smooth muscle tumors of the uterus.

Evaluation of nucleolar organizer region (NOR) parameters in the uterine leiomyoma

Nucleolar organizer regions (NORs) were assessed in 27 women affected by uterine leiomyoma. Tissue samples obtained during surgery were silver-stained according to the method of Ploton et al. The assessed parameters were as follows: the number of argyrophylic nucleolar organizer regions (AgNORs) per nucleus, single AgNOR area, AgNOR intranuclear distribution, and AgNOR coefficient. The parameters were assessed quantitatively. It was found that the AgNOR coefficient was higher in uterine leiomyoma compared to the normal smooth muscle cells. The development of leiomyoma is associated with a marked decrease in myocyte nucleolar area, which accounts for 30% of the nucleus in the normal myometrium. With the comparable AgNOR number in the single nucleus, there were no differences in the single AgNOR granule area (1.21 microm2 +/- 0.047 and 1.11 microm2 +/- 0.025 in normal myometrium and in leiomyoma, respectively). In the normal myometrium, there was a positive correlation between nuclear area and the single AgNOR granule area, as well as between the AgNOR coefficient and the single AgNOR granule area. There was also a negative correlation between the number of granules per nucleus and their central and peripheral intranuclear distribution. The development of leiomyoma was associated with loss of all correlations observed in the control group.