Expression of interphasic nucleolar organizer regions in normal, dysplastic and neoplastic colorectal mucosa

The use of epithelial membrane antigen and silver-stained nucleolar organizer regions testing in the differential diagnosis of mesothelioma from benign reactive mesothelioses

BACKGROUND

The accurate diagnosis of pleural lesions obtained from small closed biopsy is difficult. As yet there is no single reliable test to distinguish between malignant and benign mesothelial tissue.

METHODS

Immunostaining of epithelial membrane antigen (EMA) and the quantitation of silver stained nucleolar organizer regions (AgNORs) each were applied to benign and malignant histologic sections of pleural and peritoneal biopsies. The usefulness of these stains was tested both individually and in combination in the diagnosis of epithelial malignant mesothelioma.

RESULTS

One hundred and three of the 141 malignant lesions (73%) were immunoreactive for EMA but only 3 of the 73 benign lesions (4%) reacted equivocally, and none positively. The average count of AgNORs/cell in malignant lesions (n = 80) was elevated compared with benign cases (n = 26), but a significant overlap was exhibited in the AgNOR count and this form of analysis was considered to be of little value in distinguishing benign from malignant mesothelial processes. Much less overlap was observed when the average AgNOR area was measured. By using the maximum benign AgNOR area of 0.6677 microm2 as the upper threshold, 51 cases (63.8%) were identified as malignant; the test demonstrated 100% specificity and 63.8% sensitivity. By combining the EMA and AgNOR results, 76 of 80 of the malignant mesothelioma cases (95%) tested positive for at least 1 of the tests with no false-positive results identified.

CONCLUSIONS

This study confirms the usefulness of EMA in diagnosing malignant and benign mesothelial lesions, and demonstrates the enhanced diagnostic value of combining EMA immunoreaction with the average area of AgNOR per cell, thereby increasing sensitivity in the diagnosis of epithelial malignant mesothelioma.

Significance of the expression of proliferation-associated nucleolar antigen p120 in human colorectal tumors

Nucleolar protein p120 is considered to be associated with cell proliferation and has also been detected in a broad range of human malignant cells and tissues, but not in either normal resting tissue or most benign tumors. To clarify the significance of the expression of p120 in colorectal tumors or to evaluate the contribution of p120 in the development of colorectal carcinoma, the authors developed a monoclonal antibody against p120 and then examined its expression in adenoma, carcinoma, and normal mucosa. In adenomas, p120 expression was shown in none of 13 cases of mild dysplasia (0%), 2 of 15 of moderate dysplasia (13.3%), and in 2 cases of severe dysplasia (100%). p120-positive adenomas of moderate dysplasia tended to be larger and had higher Ki-67 indexes than the negative ones (adenomas of moderate dysplasia). All 27 carcinomas were positive for p120. p120 immunostaining was found in the nuclei and corresponded closely to the prominent nucleoli of tumor cells. In contrast, either weak or the occasional expression of p120 was traced in only one of the nine normal mucosae (11.1%). Three of the transitional mucosae of the carcinoma were also positive for p120. The percentage of p120-positive tumor cells (p120 index) ranged from 3.2% to 86.6%, and the mean p120 indexes of the four adenomas and all carcinomas were 21.3% and 41.5%, respectively. The p120 index was significantly related to the Ki-67 index (P < .001) in the p120-positive tumors, whereas the p120 index of the carcinoma did not significantly correlate to the known prognostic markers, such as tumor size, stage, or the degree of differentiation. These results thus suggest that the expression of p120 serves as a marker for cells with a high proliferative potential and is linked to the late events of colorectal tumor progression.

Diagnostic value of AgNOR method in thyroid cytopathology: correlation with morphometric measurements

A silver staining technique was applied to 51 thyroid smears. The numbers of silver-stained nucleolar organizer regions (AgNORs) were counted, and the mean AgNOR and nuclear area per cell were determined with an image analyzer. The mean AgNOR count per cell was significantly higher in malignant than in benign lesions, but there was a considerable overlap. The mean AgNOR area and the mean SD of the AgNOR area per cell were significantly higher in carcinomas than in benign lesions (P = 10-9 and P = 5 x 10-10, respectively) and there were only two and one benign cases, respectively, of overlap. A strong correlation was observed between the mean AgNOR area and the mean nuclear area (r = 0.88), the former being a better discriminator between benign and malignant lesions. The AgNOR technique may contribute to routine thyroid cytopathology.

Nucleolar organizer regions in adenoid cystic carcinoma of the salivary glands

In this study of proliferative activity of adenoid cystic carcinomas (ACCs) with different histological patterns, the argyrophilic staining method of nucleolar organizer regions (AgNORs) was applied to paraffin sections from 25 tumors. Sixteen of the neoplasms showed a mixture of different histological patterns in the same section. The AgNOR numbers in the different histological pattern areas in the same tissue sections of all 16 tumors were lowest in the cribriform, intermediate in the trabecular, and highest in the solid pattern areas. The mean AgNOR number was highest in the solid pattern (3.33 +/- 0.52), and lowest in the cribriform pattern (2.12 +/- 0.43). The results show the order of proliferative activity in the different histological pattern areas of ACC, and explain the previous clinical finding that the prognosis of ACC is poorest in solid pattern ACCs. AgNOR staining appears to be a useful technique for evaluation of the proliferative activity of each histological pattern area of ACC, especially when there are different histological pattern areas in the same tissue section.

Argyrophilic nucleolar organizer regions may help the differential diagnostic distinction between chronic pancreatitis and pancreatic ductal adenocarcinoma

BACKGROUND

The aim of this study was to determine whether the number of argyrophilic nucleolar organizer regions (AgNORs) could be of diagnostic significance in differentiating between chronic pancreatitis and pancreatic ductal adenocarcinoma.

METHODS

The number of AgNORs was enumerated in biopsy specimens of normal pancreas, chronic pancreatitis, and pancreatic ductal adenocarcinoma.

RESULTS

The number of AgNORs was lower in patients with normal pancreas than in patients with chronic pancreatitis or pancreatic adenocarcinoma. In addition, the number of AgNORs was significantly lower in chronic pancreatitis than in pancreatic ductal adenocarcinoma (p < 0.001).

CONCLUSIONS

The diagnosis of pancreatic adenocarcinoma is usually clear. Difficulties can be encountered, however, in cases of chronic pancreatitis, specially when biopsy material is small. Our results suggest that the number of AgNORs may help in distinguishing between chronic pancreatitis and pancreatic ductal adenocarcinoma, especially in diagnostically difficult specimens.

The value of the AgNOR staining method in identifying carcinoma in situ testis

An early and reliable diagnosis is necessary in order to have the chance of a curative therapy of Carcinoma in situ testis (Cis). Forty-six testicular biopsies were investigated to assess the value of the AgNOR staining method in comparison to placental alkaline phosphatase (PLAP) immunostaining. Both methods provided corresponding results and identical tumor cells were recognized in serial sections. The mean AgNOR counts per nucleus were 26.86 (19-52, SD: 2.68) for CIS cells, 8.18 (5-14, SD: 2.20) for spermatogonia and 12.96 (9-18, SD: 2.44) for Sertoli cells, without the counts overlapping within these three groups. Even single CIS cells are easily and reliably recognizable by their typical AgNOR pattern and their high AgNOR count per nucleus. The independent estimation of 9 testicular biopsies with the AgNOR staining method and the PLAP immunostaining correspondingly revealed 7 biopsies with CIS. Two biopsies lacked tumor cells. The AgNOR staining method can be recommended as an additional diagnostic tool in identifying CIS, because of the short and convenient staining procedure, low costs and the applicability on formalin-fixed and paraffin-embedded material.

Image analysis of Ag-NOR proteins in transitional cell bladder cancer

Nuclear organizer regions (Ag-NORs) were visualized using the standard silver-staining technique in biopsy specimens from 112 bladder carcinomas. The area of individual Ag-NOR dots and the area of Ag-NOR protein/nucleus were measured using a Quantimet 570 image analyser and the results were then correlated with clinical, histological, and quantitative prognostic factors, and survival. The mean area of Ag-NOR dots was not significantly related to any of the features analysed. The mean area of Ag-NOR protein/nucleus was related to WHO grade (P = 0.0004), papillary status (P = 0.004), DNA ploidy (P = 0.02), S-phase fraction (P = 0.02), mitotic frequency/mm2 of enoplastic epithelium (P = 0.005), mean nuclear area (P = 0.001), and SD of nuclear area (P = 0.001). In the entire cohort, the mean area of Ag-NOR protein/nucleus was related to progression with a borderline significance (P = 0.09), while in survival analysis only Ag-NOR count/nucleus had prognostic value (P = 0.010). In Ta-T1 tumours, Ag-NOR protein area/nucleus predicted progression (T-category) (P = 0.016) and survival (P = 0.014) significantly. Also, the mean area of individual Ag-NOR dots (P = 0.026) and Ag-NOR count/nucleus (P = 0.014) were related to prognosis in Ta-T1 tumours.

Comparing flow cytometric analysis and nucleolar organizer region enumeration in archival oral premalignant lesions

Flow cytometric analysis (FCA) and silver colloidal nucleolar organizer region-associated protein staining (AgNOR) have been used individually in assessing the histopathologic nature of various human tumors. However, few researchers have investigated the relationship between the two techniques in a single series. In a retrospective study, we examined 36 premalignant lesions of the oral cavity by FCA and AgNOR on formalin-fixed, paraffin-embedded tissue submitted to the University of Tennessee, Memphis, oral pathology laboratory. Three categories of epithelial dysplasia were represented (9 mild, 9 moderate, 6 severe), as well as four epithelial hyperplasias without dysplasia, three squamous cell carcinomas, and five fibrous nodules as controls. Parameters recorded for each case included age, race, gender, site, light microscopic diagnosis (LMD), DNA index (DI), total proliferative index (TPI), S-phase (S), range of nucleolar organizer regions (RNOR), and mean number of nucleolar organizer regions (MNOR). The average maximum nucleolar organizer region count (AMXNOR) for each LMD category was also calculated. The objective of the study was to determine if FCA or AgNOR aided in the subjective LMD of oral premalignant lesions and if the parameters recorded for the specimens exhibited any positive correlation. The FCA results indicated an abnormal DI in 6 of the 24 dysplastic lesions. A positive partial correlation was seen between DI and MNOR (r = 0.434; P < 0.012) and TPI and S (r = 0.774; P < 0.0001), holding gender and race constant. Additionally, the AMXNOR exhibited a slight tendency to increase for each increasing grade of dysplasia but this could not be confirmed statistically.(ABSTRACT TRUNCATED AT 250 WORDS)