The differential diagnosis of epithelial-type mesothelioma from adenocarcinoma and reactive mesothelial proliferation

Three monoclonal antibodies (mAbs) have been applied to 14 adenocarcinomas, eight mesotheliomas, and nine reactive mesothelial proliferations. One of these, AUA1, is a novel antibody in this context. It was found in 13/14 of the adenocarcinomas but not in benign or malignant mesothelial tissue, making it a potential substitute for carcinoembyronic antigen (CEA) in the differential diagnosis of mesotheliomas from adenocarcinomas. In addition, the lesions were stained using an argyrophil technique to identify nucleolar organizer regions. The results of counting these showed a small but significant overlap in their numbers between malignant and benign mesothelial proliferations. Although there was a difference overall in the numbers of nucleolar organizer regions in adenocarcinomas and mesotheliomas, on the one hand, and benign hyperplasias, on the other, this overlap considerably reduces their value in assessing individual difficult cases.     

Breast carcinoma kinetics. Argyrophilic nucleolar organizer region counts correlate with Ki67 scores

This study assessed the value of argyrophilic nucleolar organizer region (AgNOR) staining as a potential technique for the estimation of cell kinetics in conventional histology sections, in benign and malignant breast lesions. Using a silver staining technique and immunohistochemistry, the authors correlated the numbers of argyrophilic nucleolar organizer regions (AgNORs) and Ki67 scores in 70 breast carcinomas and 27 benign breast lesions. Epithelial cells in fibrocystic disease and fibroadenomas contained a mean of 2.65-6.8 small uniform AgNORs per cell, whereas malignant cells contained 4.6-26.9 frequently highly irregular AgNORs. In benign tissue, Ki67 scores ranged from 0 to 4%; in malignant tumors, Ki67 scores ranged from 3.0 to 98%. The correlation between AgNOR counts and Ki67 scores was highly significant (P less than 0.001). The authors concluded that AgNOR counts performed on routine formalin-fixed paraffin sections furnish significant kinetic information. Furthermore, the difference in AgNOR counts between benign and malignant tumors is such that they may be of diagnostic value.     

Nucleolar organizer regions in benign and malignant prostatic disease

A modified silver stain technique for visualizing nucleolar organizer regions (AgNOR counting) was applied to 24 benign and 23 malignant prostatic biopsies. Marked inter-observer variation was found, particularly in sections with high AgNOR counts. After averaging the AgNOR counts of both observers, there was no significant difference in counts between the benign and the malignant biopsies. The AgNOR count appeared to be increased in tumours up to Gleason histological grade 6, but not in tumours of Gleason histological grade 7 or more.     

The value of NOR numbers in neoplastic and non-neoplastic epithelium of the stomach

Using a silver staining technique, nucleolar organizer region-associated proteins (AgNORs) have been studied in paraffin sections of 15 benign gastric ulcers, seven early gastric cancers, 13 gastric adenocarcinomas and 10 control cases. A significant difference in the mean number of AgNORs per nucleus was found when control and benign groups were compared with the malignant group. However, there was an overlap between each category. Further studies are warranted to determine if this may be of value in differentiating regenerative epithelium from early malignancy.     

Nucleolar organizer regions in melanocytic dysplasia and melanoma

Using silver (Ag) staining to demonstrate nucleolar organizer region-associated proteins (AgNORs), pigmented naevi exhibiting features of melanocytic dysplasia have been examined and compared with benign intradermal and compound naevi and with malignant melanomas. A highly significant difference was found between the numbers of AgNORs demonstrated in benign naevus cells and atypical melanocytes and in malignant melanocytes, suggesting that this technique may have a role in differentiating between difficult melanocytic lesions.     

Studies an morphological typing of argyrophilic nucleolar organizer regions

Morphological typing of argyrophilic nucleolar organizer regions (AgNOR) in 300 caws of malignant tumors and 140 cams of benign lesions was analyzed and five morphological types of ApNOR were described in detail. In malignant tumors, the diffuse type (78%) was the most frequently seen, and in benign lesions, the nucleolar type (92.85%); the difference was thus highly significant (P < 0.001). The intranucleolar and aggregate types were not observed in benign lesions. There was no obvious difference in the proportion of the mixed type in benign and malignant lesions (P > 0.05). The relationship between grade of malignancy and morphological typing of AgNOR and its clinical significance are discussed.     

Diagnostic Value of Silver-Stained Interphasic Nucleolar Organizer Regions in Breast Tumors

Seventy-six specimens of normal breast tissue and benign and malignant breast lesions were studied to assess the mean area occupied by silver-stained proteins of the nucleolar organizer regions (MNORA) of the nucleolus. The assessment was performed with a computer-assisted image analyzer. The results indicate that only 30% of malignant lesions have a MNORA value greater than that of normal breast tissue or benign lesions. On the other hand, MNORA values of ductal carcinoma in situ were significantly greater than those of epitheliosis (papillomatosis). MNORA values were also significantly different in grade I and grade III invasive ductal carcinomas, the latter exhibiting the highest MNORA values of all the cases observed. Evaluation of MNORA values may therefore help in differentiating benign epithelial proliferations from ductal carcinomas in situ. Furthermore, because there is evidence that MNORA values are indicative of the cell duplication rate, MNORA values may ultimately be considered an objective prognostic parameter in addition to grading for invasive ductal carcinomas.     

Salivary gland tumours studied by means of the AgNOR technique

Difficulty is sometimes encountered in distinguishing between pleomorphic adenoma, adenoid cystic carcinoma and adenocarcinoma, especially in small biopsies from salivary glands. The argyrophil (AgNOR) staining technique for nucleolar organizer regions (NORs) has been applied to a series of benign and malignant salivary gland tumours. We studied 35 salivary gland tumours, 13 benign and 22 malignant. In all specimens clearly defined silver-stained intranuclear AgNOR dots were visible. The differences between the numbers of AgNORs in the benign and malignant groups, notably pleomorphic adenomas, adenoid cystic carcinoma and adenocarcinoma, were highly significant. In view of this difference we propose that the AgNOR staining technique is of diagnostic help in distinguishing between these salivary gland tumours.     

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 × 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. Diagn Cytopathol 1996;14:140–144. © 1996 Wiley-Liss, Inc.     

皮肤表皮良,恶性病变的核仁组成区定量研究

使用银染技术对皮肤乳头状瘤、表皮假癌状增生及高、中、低分化的鳞状细胞癌进行核仁组成区(AgNORs)定量观察。结果表明,皮肤乳头状瘤与表皮假癌状增生之间AgNORs无明显差异,鳞状细胞癌核内AgNORs颗粒的数目、大小及分布则与它们有明显差异(P<0.01)。3种不同分化程度的鳞状细胞癌,在平均每核AgNORs数目及周边型AgNORs颗粒等方面差异均非常显著(P<0.01)。这些结果提示,AgNORs定量观察不仅有助于良、恶性肿瘤的鉴别,而且还有助于恶性肿瘤的分级。     

Diagnostic significance of mean numbers of nucleolar organizer regions in benign and malignant transitional tumours of nose

On the basis of a silver colloid technique to identify nucleolar organizer region-associated protein (AgNOR) counts, transitional papillomas of the nose showing malignant change could easily be distinguished from their benign counterparts and both could be distinguished from invasive carcinomas.     

The value of nucleolar organizer region staining in the differential diagnosis of borderline melanocytic lesions

The technique of silver (Ag) staining of nucleolar organizer region-associated proteins (AgNORs) has been shown to be of value in differentiating between benign and malignant cells. We have studied 33 borderline melanocytic lesions, in which a diagnosis of melanoma had been seriously considered, in order to assess the value of this technique in a commonly encountered diagnostic situation. We found that benign naevus cells possessed single compact or granular AgNORs, whereas some malignant melanocytes possessed large, often loosely arranged groups of AgNORs. However, the pattern of AgNORs observed in melanocytes of some atypical but benign lesions was also seen in some melanomas. The differential diagnosis of borderline melanocytic lesions is not clarified by use of the AgNOR technique.     

Utility of morphometry and nucleolar organizer regions count in the differentiation of reactive and malignant mesothelial cells in pleural effusions

The authors have evaluated in eight reactive and eight malignant pleural effusions the number of intranucleolar dots representing the nucleolar associated proteins stained with silver colloid technique (interphase nucleolar organizer regions-AgNOR). The mean number per nucleus in benign reactive mesothelium was significantly lower than in mesothelioma effusions. Other morphometric measurements of nuclear diameters and areas were effected. The authors evaluate the variability of the AgNOR counts and morphology in reactive and mesothelioma cells of pleural fluids.     

Silver-stained nucleolar organizer regions in the differentiation of prostatic hyperplasia, intraepithelial neoplasia, and adenocarcinoma.

Nucleolar organizer regions (NORs) are loops of chromosomal DNA that ultimately direct the development of the nucleolus. These NORs are associated with argyrophilic acidic nonhistone proteins which have allowed the demonstration of NORs by a simple silver stain. This staining technique has been used to examine the number of silver-stained NORs (AgNORs) in malignant and benign conditions, and, in general, AgNOR numbers are increased in malignant tissues when compared with normal or benign conditions. More recently, this technique has been applied to premalignant lesions with varying results. We applied this silver stain to prostate lesions where nucleolar features are of diagnostic importance. The stain was applied to ten cases of prostatic hyperplasia, ten cases each of prostatic intraepithelial neoplasia (PIN) grades 1 through 3, and ten cases each of low grade, intermediate grade, and high grade adenocarcinoma. The counting was performed by image analysis. A significant mean difference did exist between low grade and the two higher grades of adenocarcinoma. There was no significant difference in AgNOR counts per nucleus in hyperplasia, PIN, or adenocarcinoma or between the three grades of PIN. The AgNOR silver stain is not useful in the differentiation of hyperplasia, the three grades of PIN, and adenocarcinoma. Also because of overlap among the three grades of adenocarcinoma, it is not useful in the differentiation of these lesions.     

Nucleolar organizer regions in normal,hyperplastic and neoplastic parathyroid glands

Summary Using a one-stage silver staining technique, nucleolar organizer regions (AgNORs) were studied in paraffin sections of parathyroid glands (and in two lymph node metastases) from patients operated upon because of hyperparathyroidism or thyroid disease. The parathyroids were microscopically differentiated into normal, hyperplastic, adenomatous and carcinomatous glands. AgNORs were observed as distinct black dots of varying size and somewhat varying configuration in the nuclei of all glands. The mean number of AgNORs in the hyperplastic and adenomatous glands was not significantly different from that in the normal glands, whereas the carcinomatous glands exhibited significantly increased mean AgNOR number. No evidence was obtained for a role of AgNOR counting in the differentiation between normal and hyperplastic or adenomatous parathyroids, but the results suggest a potential role of enumeration of AgNORs in the discrimination between benign and malignant parathyroid neoplasms.     

Standardized in situ AgNOR analysis in breast pathology: diagnostic and cell kinetic implications.

The aim of the present study was to assess the diagnostic value of the recently standardized morphometric analysis of silver-stained nucleolar organizer region-associated proteins (AgNORs) [30] in a variety of 155 routinely processed benign and malignant breast lesions. 5 normal breast samples, 21 adenoses, 20 ductal hyperplasias, 10 atypical ductal hyperplasias, 20 in situ and 43 invasive ductal carcinomas, 10 in situ and 26 invasive lobular carcinomas were investigated. A statistically highly significant difference was found between normal/ordinary hyperplastic and neoplastic breast lesions with all 4 consensus AgNOR parameters (mean area, mean number, CV of area, CV of number) evaluated. AgNOR quantity was significantly related to histological grade of both in situ and invasive carcinomas. However, variable overlap was found between AgNOR values in different diagnostic groups. We conclude that standardized AgNOR analysis is a prerequisite for objective and reproductible AgNOR assessment in archival tissues. Despite its limited diagnostic utility for individual breast lesions, standardized AgNOR analysis bears a significant potential for characterizing cell kinetic and metabolical activity of breast lesions. This may give insight into the biological background of breast carcinogenesis, differentiation and tumor progression and may also underlie the independent prognostic value of AgNORs in breast cancer.     

Evaluation of AgNOR count in distinguishing benign from malignant mesothelial cells in pleural fluids.

The authors have evaluated in eight reactive and eight malignant pleural effusions the number of intranuclear dots representing the nucleolar associated proteins stained with silver colloid technique (interphase nucleolar organizer regions-AgNORs). The mean number per nucleus in benign reactive effusions was 1.56 (SD 0.77) while in mesotheliomatous effusions it was 2.81 (SD 1.44). The statistical analysis of values, by Mann-Whitney U Wilcoxon Rank Sum W Test, revealed a significant difference of AgNOR counts in the two cytological samples. The variability of AgNOR areas and morphologies in reactive and mesotheliomatous nuclei in pleural fluids is evaluated applying automatic image analysis.     

Correlation of nucleolar organizer regions and glandular dysplasia of the stomach and esophagus

Forty-seven biopsies of gastric mucosa and Barrett esophagus from 32 patients were studied with the argyrophilic nucleolar organizer region method. Twenty-two biopsies were gastric and 25 esophageal. Four showed normal noninflamed mucosa, 14 reactive glandular changes, eight intestinal metaplasia without dysplasia, ten low grade dysplasia with intestinal metaplasia, and 11 high grade dysplasia. The mean number of nucleolar organizer regions was 14.9 for high grade dysplasia, 10.9 for low grade dysplasia, 8.5 for intestinal metaplasia without dysplasia, 6.7 for reactive changes, and 3.9 for normal mucosa. The difference between high grade dysplasia and the other groups was significant (P = 0.004). However, the difference between high and low grade dysplasia was not significant (P = 0.06), and there was an overlap between reactive and high grade dysplastic lesions. We conclude that although nucleolar organizer counts correlate with the degree of dysplasia, the technique is of limited practical use.     

PCNA表达及AgNOR检测对鉴别口腔良恶性病变的应用

目的探讨增殖细胞核抗原(PCNA)及核仁组成区嗜银蛋白计数在诊断口腔良恶性病变中的意义。方法采用免疫组化SP方法及银染技术对40例口腔恶性肿瘤、6例交界性肿瘤及44例良性病变进行检测。结果PCNA在恶性肿瘤组、交界性肿瘤(临界组)及良性病变组的阳性表达率分别为67.5%、16.7%及2.27%,AgNOR颗粒计数分别为3.95±0.32、2.75±0.25、1.42±0.26。恶性肿瘤中的PCNA强阳性表达率及AgNOR计数明显高于良性病变(P<0.05)。结论检测PCNA和AgNOR对口腔病变的良恶性鉴别诊断、恶性程度判定及预后评估有一定的临床应用价值。