p53 and Ki-67 immunoreactivity and nuclear morphometry of 'carcinoma-in-adenoma' and adenoma of the gall-bladder

Twenty Intramucosal tumors of ‘carclnoma-ln-adenoma’ and 43 adenomas (39 pylorlc gland type, 4 Intestinal type) of the gall-bladder were studied to establish more precise hlsto-loglcal criteria of carcinoma or adenoma in cases of ‘carcinoma in pylorlc gland type adenoma’, to compare carcinoma in adenoma with pure, that is, without adenomatous components, carcinoma, and to confirm the benign nature of spindle cell foci in the adenomas. Ki-67 and p53 immunostaining and nuclear morphometry were used. Eight pure intramucosal cancers were used as controls. The formalin-fixed, paraffin-embedded sections were stained with p53 and Ki-67 antibodies. Spindle cell foci were observed only in the adenoma area of the pylorlc gland type, with a frequency of 23% in 39 adenomas, and of 45% in 20 tumors of carclnoma-Jn-adenoma. Ki-67 staining was negative in 129 of 130 spin-die cell foci examined, regardless of their size, and positive in only one focus (550 μm in size, Ki-67 index 0.2%). All of the spindle cell foci were negative for p53 stain. The Ki-67 positive index was 36.6 ±5.6% in the 8 pure carcinomas, and 12.5 ±1.9% in the carcinoma area of 16 tumors with carci-noma-in-adenoma, while it was 7.9± 1.7% and in the adenoma areas of 16 tumors with carcinoma-in-adenoma and 4.9 ± 0.5% in the 32 pure pyloric gland adenomas. The p53-protein overexpression was found in seven of eight pure intramucosal cancers, and in one of 16 cancer components of carcinoma-in-adenoma. However, it was not found in any of 16 adenoma components of carcinoma-in-adenoma, and 35 adenomas. Cells of the cancer tissue of carcinoma-in-adenoma showed a significantly larger nuclear area and a larger nuclear minor axis than those of the pyloric gland type adenomas, as well as other architectural and cytologic abnormalities differing from the features of adenomas. These results suggest that clustered spindle cells do not indicate a malignant transformation of adenoma cells and that carcinomas in carcinoma-in-adenoma are different from pyloric gland type adenomas in terms of morphology and proliferative activity. Moreover, the results of the present study indicate that carcinomas in carcinoma-in-adenoma are lower in malignancy than pure carcinomas, and that their genetic abnormality may differ from that of pure carcinomas.     

p53 and Ki-67 immunoreactivity and nuclear morphometry of 'carcinoma-in-adenoma' and adenoma of the gall-bladder

Twenty lntramucosal tumors of ‘carclnomaln-adenoma’ and 43 ademas (39 pylorlc gland type, 4 Intestinal type) of the gall-bladder were studied to establish more precise histo-logical criteria of carcinoma or adenoma In cases of ‘carcinoma In pyforic gland type adenoma’, to compare carcinoma In adenoma with pure, that Is, without adenomatous components, carcinoma, and to confirm the benign nature of spin-dle cell fd in the adenomas. Ki-67 and p53 immunostaining and nuclear morphomety were used. Eight pure intramucessl cancers were used as controls. The formalin-fixed, paraffln+mbedded sections were stained with p53 and Ki-67 antibodies. Splndle cell foci were observed only In the adenoma area of the pyloric gland type, wlth a frequency of 23% In 39 adenomas, and of 45% in 20 tumors of carclnoma-lrradenoma. Ki-67 staining was negative in 129 of 130 spin-die cell foci examlned, regardless of their size, and positive in only one focus (550 pm in size, Ki-67 Index 0.2%). All of the spindle cell foci were negative for p53 stain. The Ki-67 positive index was 36.6 ± 5.6% In the 8 pure carcinomas, and 12.5 ± 1.9% in the cancer areas of 16 tumors with carcinoma-in-adenoma, while it was 7.9 ± 1.7% in the adenoma areas of 16 tumors with carcinoma-in-adenoma and 4.9 ± 0.5% in the 32 pure pyloric gland adenomas. The p53-protein over-expression was found in seven of eight pure intramucosal cancers, and in one of 16 cancer components of carclnoma-in-adenoma. However, it was not found in any of 16 adenoma components of carcinoma-in-adenoma, and 35 adenomas. Cells of the cancer tissue of carcinoma-In-adenoma showed a significantly larger nuclear area and a larger nuclear minor axis than those of the pyloric gland type adenomas, as well as other architectural and cytologic abnormalities differing from the features of adenomas. These results suggest that clustered spindle cells do not indmte a malignant transformation of adenoma cells and that carcinomas in carcinoma-in-adenoma are dtfferent from pylorlc gland type adenomas In terms of morphology and proliferative activity. Moreover, the results of the present study indicate that carcinomas In carcinoma-ln-adenoma are lower In malignancy than pure carcinomas, and that their genetic abnormaltty may differ from that of pure carcinomas.     

Parathyroid neoplasms: clinical,histopathological, and tissue microarray-based molecular analysis

We studied 45 patients with typical and 8 with atypical parathyroid adenomas as well as 20 with parathyroid carcinomas. Clinical, pathological, and molecular analyses were conducted on all adenomas. Clinical data were analyzed for 20, histopathologic slides for 16, and tissue specimens for 8 patients with carcinoma. Molecular expression profiles were investigated by immunohistochemistry (IHC) for Ki-67, p53, mdm2, p21, Bcl-2, cyclin D1, and p27 on paraffin-embedded tissues arrayed on tissue microarrays. Trabecular growth and vascular, capsular, and soft-tissue invasion were characteristic of parathyroid carcinomas but not of typical adenomas. No adenomas recurred. Seventy-four percent of carcinomas recurred, most in the neck. Seventy-nine percent of patients with such illness died of disease after an indolent, multiply recurrent course responsive to repeated resections; the 5-year survival rate was 50%. High Ki-67 proliferative index was seen in 2% of adenomas and 25% of carcinomas, whereas p27 expression was present in 80% of adenomas and 18% of carcinomas. The molecular phenotype, p27(+)Bcl-2(+)Ki-67(-)mdm2(+), was observed in 76%, 29%, and 0% of typical and atypical adenomas and carcinomas, respectively. The complexity of molecular phenotypes increased with tumor aggressiveness. Parathyroid carcinoma is an aggressive disease with a propensity for multiple recurrences. It is characterized by capsular, vascular, and soft-tissue invasion. Recurrence portends poor outcome. Molecular markers, Ki-67 and p27, may distinguish parathyroid carcinoma from adenoma. The molecular phenotype, p27(+)Bcl-2(+)Ki-67(-)mdm2(+), appears to be unique to nonmalignant parathyroid tumors, and multimarker phenotypes are more complex in carcinomas.     

Aberrant p27kip1 expression in endocrine and other tumors.

The p27kip1 (p27) gene encodes an inhibitor of cyclin-dependent kinase activity. The expression of p27 protein in normal and neoplastic tissues was investigated by immunoblotting and immunohistochemistry. Immunoblotting studies detected a 27-kd protein band that was decreased in neoplastic pituitary tissues compared with normal pituitary. Immunostaining of 177 tissues showed abundant expression of p27 protein in normal tissues with decreased numbers of immunoreactive cells in adenomas and carcinomas in both endocrine and nonendocrine tissues. p27 expression was inversely related to the proliferation marker Ki-67 antigen detected with monoclonal antibody MIB-1. Parathyroid adenomas and hyperplasias had similar Ki-67 labeling indices; however, hyperplasias had threefold more p27-positive cells than parathyroid adenomas, suggesting that p27 immunostaining may be useful in distinguishing between these two conditions. These results indicate that there is widespread aberrant p27 expression in hyperplastic tissues and in benign and malignant neoplasms compared with normal tissues. Immunohistochemical analysis of p27 along with Ki-67 may be used to assess the biological behavior of various neoplasms, to classify hyperplastic and neoplastic tissues, and to study cell cycle regulation during tumor progression.     

Different expression of Bcl-2 protein in gastric adenomas and carcinomas

In order to cast light on the possible role of bcl-2 protein (Bcl-2) expression In gastric tumorigenesis, 33 cases of gastric adenomas and carcinomas originating from the same stomachs were immunohistocnemically investigated for Bcl-2 protein (Bcl-2) expression, accumulation of p53 protein and cell proliferation as determined by the KI-67 labeling index (LI). Bcl-2 expression was detected in 24/33 (72.7%) adenomas and in 6/33 (18.2%) carcinomas, the difference being statistically significant (P=0.0O01). Only 4 of 33 (12.1%) cases exhibited expression in both adenoma and carcinoma lesions in the same stomachs. ImmunoreactMty was decreased in areas of cellular and structural atypia in adenoma lesions ( P <0.008), and appeared to be positively linked to the tumor progression and the degree of differentatlon in carcinomas, although It did not reach statistical significance. Accumulation of p53 protein was rare In the adenomas but was found in 15/33 (45.5%) of carcinoma lesions, with a significant dissociation from Bcl-2 immunoreactivity. No apparent relation between Ki-67 U and either adenoma grading or carcinoma typing was noted, although average KI-67 LI of the highest labeling areas in carcinomas was statistically higher than in adenomas ( P =0.0001). These results indicate that the regulation of Bcl-2 expression may differ between gastric adenomas and carcinomas, may be correlated with tumor dlfferentiathre features. In addition, p53 accumulation may play an Important role in the onset of malignancy.     

Proliferation Markers and EGF in ACTH-Secreting Adenomas and Carcinomas of the Pituitary

Pituitary carcinomas are only defined by their metastatic growth, which may be intracranial or systemic. To establish further morphological and immunohistochemical differences between pituitary carcinomas and adenomas, 19 ACTH-secreting adenomas (10 non invasive and 9 invasive) and 2 ACTH-secreting carcinomas with their metastases were studied for expression of the intermediate filaments keratin and vimentin and the tumor-associated antigens Ki67, proliferating cell nuclear antigen (PCNA), epidermal growth factor (EGF), cathepsin D, p53, and carcinoembryonic antigen (CEA). Immunohistochemistry was performed using avidin-biotin techniques on formalin-fixed, paraffin-embedded tissue. With the exception of one noninvasive pituitary adenoma, one carcinoma, and the metastases, all tumors contained keratin; none contained vimentin. All tumors stained negative for CEA and p53. Eleven (58.5%) adenomas and both pituitary carcinomas contained Ki67-positive nuclei; 14 (74%) adenomas and one carcinoma revealed PCNA. No correlation was found between the two markers. Seven (38%) adenomas showed a labeling index <1 % for cathepsin D, whereas none of the carcinomas or metastases did so. EGF was found in 7 (38%) adenomas and in both carcinomas. A tendency to a higher rate of EGF positivity in the invasive adenomas was observed. The metastases showed a higher labeling index, and far more intense staining results for Ki67, PCNA, and EGF than the primary tumor. The metastases also had a higher proliferation rate and growth factor content than the carcinoma itself.     

Expression of MUC1 and MUC2 mucins and relationship with cell proliferative activity in human colorectal neoplasia

Our previous studies on MUC1 and MUC2 mucin expression in various human neoplasms have found that MUC1 expression is related with a poor outcome whereas MUC2 expression is related with a favorable outcome. In the present study, we examined the alteration of MUC1 and MUC2 antigens on malignant transformation of colorectal mucosa, and also its relationship with cell proliferative activity (Ki-67 labeling index) of neoplastic epithelial cells in 200 adenomas and 58 carcinomas. In the 200 adenomas, we analyzed a total of 400 adenomatous lesions (mild dysplasia, 200 lesions; moderate dysplasia, 153 lesions; severe dysplasia, 47 lesions). MUC1 was expressed in carcinomas (24%) and adenomas with severe dysplasia (4%), but was not expressed in adenomas with mild or moderate dysplasia. MUC2 was expressed in a significantly greater number of adenomas with mild dysplasia (72%) than in adenomas with moderate dysplasia (45%) or severe dysplasia (47%), as well as in the carcinomas (38%; P < 0.0001). The Ki-67 labeling index was significantly lower in the MUC2-positive cases than in the MUC2-negative cases in the adenomas with mild dysplasia (13.6 vs 24.2%; P < 0.0001) or moderate dysplasia (25.7 vs 44.4%; P < 0.0001), and in the carcinomas (32.5 vs 48.4%; P < 0.05). In conclusion, the data from our study indicate that increased MUC1 expression and reduced MUC2 expression may be related to malignant transformation of colorectal neoplasia. We also demonstrated that decreased MUC2 expression, which is correlated with increased Ki-67 labeling, may play an important role in the progression of colorectal adenomatous change.     

Galectin-3 and Ki-67 expression in multiglandular parathyroid lesions

Hyperplastic and neoplastic parathyroid lesions may present overlapping morphologic features, and several markers have been proposed to distinguish benign from malignant growths. Recently, it was reported that galectin-3 is a useful marker of malignancy in uniglandular parathyroid diseases. To investigate galectin-3 and Ki-67 immunoexpression in parathyroid hyperplastic disease, 63 multiglandular lesions (13 primary, 40 secondary, and 10 tertiary hyperplasia cases) were analyzed and compared with 45 control cases of parathyroid adenomas and 24 carcinomas. Our data showed that hyperplastic lesions responsible for primary nonfamilial or tertiary hyperparathyroidism, as well as parathyroid adenomas, were negative for galectin-3, as opposed to carcinomas. In addition, secondary and familial primary hyperplasia cases were surprisingly positive for galectin-3 in approximately two thirds of cases. All hyperplastic lesions (positive or negative for galectin-3) had a low Ki-67 index. Based on these findings, secondary hyperplasia has a low proliferative potential but an unexplained galectin-3 reactivity, which reduces its diagnostic role in differentiating benign from malignant nodules in the context of multiglandular parathyroid diseases.     

Proliferation and apoptosis in proliferative lesions of the colon and rectum

 Classically, neoplasia has been considered to be primarily a disturbance in the regulation of proliferation, but it is now clear that programmed cell death is dysregulated as well as proliferation. The genes that are implicated in the regulation of these processes, such as p53, c-myc and bcl-2, are often also altered in neoplasms. We have studied proliferation and programmed cell death in hyperplastic polyps, adenomas, carcinomas in adenomas and adenocarcinomas of the colorectum, using the MIB-1 antibody which recognizes the Ki-67 proliferation related antigen, and an in situ nick-end labelling procedure for histochemical labelling of proliferating and apoptotic cells. In addition, immunohistochemistry was used to study the expression of the p53, c-myc and bcl-2 proteins. The material studied consisted of 12 samples of normal mucosa, 8 hyperplastic polyps, 39 adenomas with different degrees of dysplasia and including 3 that carried a carcinoma, and 10 adenocarcinomas, all formalin fixed and paraffin embedded. The Ki-67 index indicated that proliferation increased progressively in hyperplasia, through different degrees of dysplasia in adenoma, to reach the highest level (Ki-67 index of 50%) in adenocarcinoma. Apoptosis also increased in hyperplastic polyps and in adenomas, but decreased significantly in adenocarcinomas. p53 Labelling was seen in 77% of the carcinomas but in only 3% of the adenomas. Expression of c-myc increased in adenomas and carcinomas. Furthermore, a shift from predominantly nuclear to predominantly cytoplasmic expression was seen in progressive neoplasms. Expression of bcl-2 was increased in an occasional hyperplastic polyp, but was increased markedly in almost all adenomas. Strikingly, in the adenomas with a carcinoma, the carcinoma showed weaker bcl-2 expression than the adenoma. In 20% of the carcinomas some bcl-2 staining was seen but this was less extensive than in the adenomas. Our findings indicate that in the progression from adenoma to carcinoma both increased proliferation and decreased apoptosis occur. This is paralleled by an increased expression of p53 and an increased and predominantly cytoplasmic expression of c-myc, but a decreased expression of bcl-2. This decreased bcl-2 expression does not lead to an increase in apoptotic activity. Received: 16 January 1997 / Accepted: 10 March 1997     

Assessment of Mitotic Activity in Pituitary Adenomas and Carcinomas

Assessment of mitotic activity represents one of the oldest and most routinely used histopathologic methods of evaluating the biological aggressiveness of human tumors. In the case of pituitary tumors, however, the relevance of this approach as a means of gaging tumor behavior remains ill-defined. In this article, the relationship between the mitotic index and biological aggressiveness of pituitary tumors was evaluated in a series of 54 pituitary adenomas and 6 primary pituitary carcinomas. All tumors were fully classified by immunohistochemistry and electron microscopy; adenomas were further stratified on the basis of their invasion status, the latter being defined as gross, operatively, or radiologically apparent infiltration of dura or bone. Mitotic figures were present in 11 tumors, 10 being either invasive adenomas or pituitary carcinomas. A significant association between the presence of mitotic figures and tumor behavior was noted, as evidenced by progressive increments in the proportion of cases expressing mitotic figures in the categories of noninvasive adenoma, invasive adenoma, and pituitary carcinoma (3.9, 21.4, and 66.7%, respectively; Fisher’s exact test, two-tailed,p<0.001). The mitotic index, however, appeared to be a less informative parameter, being extremely low in all cases (mean=0.016%±0.005 [±SEM]). Although the mean mitotic index in pituitary carcinomas (0.09%±0.035) was significantly higher than the mean mitotic index of either noninvasive adenomas (0.002%±0.002) or invasive adenomas (0.013%±0.005), no practical threshold value capable of distinguishing these three groups was evident. Comparison of the mitotic index with Ki-67 derived growth fractions in these tumors revealed a significant but weak linear correlation (r=0.41,p<0.01). These data suggest that when, mitotic figures are present, they do provide some indication of the behavior and invasive potential of pituitary tumors. For routine diagnostic purposes, however, the discriminating power of this parameter is somewhat limited, being superseded by alternative and more informative methods of growth fraction determination such as that provided by the Ki-67 immunolabeling.     

Usefulness of endoscopic biopsy using immunostaining of p53 and Ki-67 in tumors of the ampulla of Vater

We investigated the diagnostic and prognostic value of p53 expression and proliferative activity, as indicated by the Ki-67, in endoscopic biopsy specimens. Specimens were immunologically stained with p53 and MIB-1 (Ki-67), and the MIB-1/Ki-67 labeling index (LI) was calculated. Classification of adenomas was based on findings of H&E-stained preparations into those with low- or high-grade atypia. Well-differentiated tubular and papillary adenocarcinomas were classified as carcinomas with low- or high-grade atypia. There were significant differences among the control and adenoma patients in MIB-1/Ki-67 LI (P < 0.05). No significant difference was identified between adenomas with high grade atypia and carcinomas with low grade atypia. The p53 expression was negative in all adenomas, but it was positive in 68.2% of carcinomas. The current study demonstrated that p53 protein expression in endoscopic biopsy specimens was of preoperative diagnostic value for carcinoma of the ampulla of Vater. The p53 protein positive tumors had a relatively higher malignant potential than p53 protein negative ones. The MIB-1/Ki-67 LI was useful in differentiating non-tumorous lesions from adenomas and adenomas with low- or high-grade atypia. The MIB-1/Ki-67 LI had a prognostic value because clinicopathological factors of carcinoma of ampulla of Vater correlated with MIB-1/Ki-67 LI.     

Pathologic features, proliferative activity, and cyclin D1 expression in Hurthle cell neoplasms of the thyroid.

Making a histologic distinction between Hurthle cell adenomas and carcinomas sometimes may be difficult. We analyzed a series of Hurthle cell lesions to determine whether specific histologic features and expression of Ki67 and cyclin D1 could be useful in distinguishing Hurthle cell adenomas from carcinomas. Formalin-fixed, paraffin-embedded tissues from 128 Hurthle cell neoplasms, including 59 adenomas; 55 carcinomas; and 14 tumors classified as neoplasms of uncertain malignant behavior (UMB), which had equivocal capsular invasion but no vascular invasion, were analyzed for expression of Ki67 and cyclin D1 by immunostaining. The distribution of immunoreactivity for Ki67 with antibody MIB-1 was analyzed by quantifying the percentage of positive nuclei that was expressed as the labeling index. None of the patients with adenomas or UMB tumors developed recurrent or metastatic disease after a mean follow-up of 7.8 and 7.9 years, respectively. Of the 55 patients with Hurthle cell carcinoma, 19 were associated with metastatic disease, 13 of whom died with disease. No patient with a Hurthle cell carcinoma without vascular invasion developed metastatic disease. The mean tumor size for Hurthle cell carcinomas (4.8 cm) was significantly larger than that of Hurthle cell adenomas (3.1 cm) or UMB tumors (3.7 cm). No patient with a Hurthle cell tumor smaller than 3.5 cm developed metastatic disease, even when vascular invasion was present. The Ki67 labeling index in Hurthle cell carcinomas (10.0 +/- 1.2) was 3-fold higher than in Hurthle cell adenomas (3.2 +/- 0.3). The Ki67 labeling index in the UMB group was 5.0 +/- 0.7. Cyclin D1 showed diffuse nuclear staining in 1 of the 59 (1.7%) Hurthle cell adenomas, in 10 of the 55 (18%) Hurthle cell carcinomas, and in none of the UMB tumors. In summary, analyses of the cell cycle proteins Ki67 and cyclin D1 in Hurthle cell thyroid neoplasms indicate that these markers may assist in distinguishing some Hurthle cell carcinomas from adenomas. Among the Hurthle cell carcinomas, large tumor size and vascular invasion are associated with clinically aggressive tumors. Our study also suggests that Hurthle cell neoplasms with only equivocal capsular invasion and no vascular invasion should behave in a benign manner.     

Immunohistochemical analysis of cell kinetic parameters in colonic adenocarcinomas, adenomas, and normal mucosa

The monoclonal antibody Ki-67 identifies a nuclear antigen that is expressed in proliferating cells in G1, G2, S, and M phases of the cell cycle. An immunoperoxidase method and this antibody were used to identify proliferating cells in sections of colorectal tissues--normal colon (n = 10), colorectal polyps (n = 20), and adenocarcinoma (n = 28). Colorectal adenomas showed a uniform distribution of positive nuclear staining throughout the sections, including the cells of the adenoma surface, while staining in the normal mucosa was confined to the middle third and lower third of the crypts. Areas of polyps with numerous Ki-67-positive epithelial cells invariably showed immature or dysplastic histology and, conversely, glands that lacked such histologic features had low Ki-67 staining frequency or were negative. In adenomas, nuclei located toward the luminal surface of glands were more likely to be Ki-67-positive than those located basally in the cells. The mean Ki-67 score (a measure of positive staining nuclei) for adenomas was 45.5 compared to a mean score of 66.3 for adenocarcinomas in the carcinomas studied (P less than .001). Ki-67 score did not correlate with histologic grade or Duke's stage. Ki-67 staining can be used to characterize the proliferative characteristics of normal colonic mucosa, adenomas, and carcinomas.     

Immunohistochemical detection of proliferating cells in colorectal carcinomas and adenomas with the monoclonal antibody Ki-67. Preliminary data

Summary Twenty one cases of colorectal adenocarcinoma and six of adenoma have been studied using the monoclonal antibody Ki-67 which recognizes a nuclear antigen expressed by proliferating cells (PC). The quantitative evaluation of the stained nuclei showed that PC were more numerous in carcinomas than in adenomas although the difference did not reach a significant level. In each tumour, heterogeneity was noted. Furthermore, the superficial areas of both carcinomas and adenomas contained a greater number of PC than the deep. No difference was noticed in the various types and grades of differentiation for carcinomas. This preliminary report, compared with the only previous study of Shepherd et al. (1988) outlines the interest of the monoclonal antibody Ki-67 in the evaluation of growth fractions in colorectal tumours.     

The Incidence of Apoptosis During Colorectal Tumorigenesis

Epithelial homeostasis in colorectal tumorigenesis is dependent not only on the rate of cell production but also on the rate of apoptosis, a genetically programmed process of autonomous cell death. Ideally, an analysis of cell kinetics should be carried out for both cell proliferation and death. We investigated the incidence of apoptosis in 35 colorectal neoplasms (15 adenomas and 20 carcinomas) using the DNA nick end labeling method (TUNEL). The expression of Ki-67 as a marker of proliferating activity and some kinds of oncogene products were analyzed immunohistochemically. When the TUNEL labeling index (TI) and the Ki-67 labeling index (KI) were determined, TI was found to be significantly higher in adenomas with high-grade dysplasia (TI: 2.5%) than in adenomas with low-grade dysplasia (TI: 0.6%) or carcinomas (TI: 1.4%). In contrast, KI increased with the progression of colorectal tumorigenesis. Moreover, TI of the carcinomas was significantly higher in c-Myc-positive cases than in c-Myc-negative cases (p<0.05). The results indicate that apoptosis plays an important role in the early stage of the adenoma-carcinoma sequence, permitting us to speculate that the increased tumor cell proliferation is negated by increased apoptosis at the stage of adenoma with high-grade dysplasia (or intramucosal carcinoma), while cell proliferation overwhelms cell death at the stage of invasive carcinoma. Int J Surg Pathol 8(2):123-132, 2000     

Differential expression of the calcium sensing receptor and combined loss of chromosomes 1q and 11q in parathyroid carcinoma

Malignant transformation of parathyroid tumours is rare. Nevertheless, this small subset of malignant tumours often creates diagnostic and therapeutic problems. In this work, the morphological characteristics of 26 primary parathyroid carcinomas and seven metastases have been studied. Furthermore, immunohistochemical expression profiles for the calcium sensing receptor (CASR), cyclin D1 (CCND1), and Ki-67 were determined for parathyroid carcinomas and compared with adenomas and hyperplasias using a tissue microarray. Loss of heterozygosity (LOH) of the chromosome 1q region containing the HRPT2 gene and chromosome 11q (MEN1) was determined in the carcinomas. In contrast to the adenomas and hyperplasias, 31% of carcinomas demonstrated down-regulation of CASR. A significant correlation was found between CASR expression and the Ki-67 proliferation index. Chromosome 1q and chromosome 11q LOH were found in 12 of 22 (55%) and 11 of 22 (50%) carcinomas tested, respectively. Combined 1q and 11q LOH was seen in 8 of 22 (36%) carcinomas, in contrast to the low percentage of LOH reported in both regions in adenomas. In conclusion, this study demonstrates that combined 1q and 11q LOH in parathyroid tumours is suggestive of malignant behaviour. Strong down-regulation of the CASR protein is seen in a proportion of parathyroid carcinomas with a high proliferation index.     

Flow cytometric DNA analysis of parathyroid glands. Relationship between nuclear DNA and pathologic classifications

Nuclear DNA contents of 95 paraffin-embedded parathyroid glands (2 carcinomas, 56 adenomas, 10 primary and 17 secondary chief cell hyperplasias, and 10 normal glands) were determined by flow cytometric analysis. All normal parathyroid glands and secondary hyperplasias, 80% of the primary hyperplasias, and 73% of the adenomas had diploid DNA patterns, with 15% or less tetraploid cells. Twenty-one percent of the adenomas, 29% of the primary hyperplasias, and all carcinomas had diploid and tetraploid DNA distribution patterns, with greater than 15% of the cells in the tetraploid region. One of the carcinomas (Figure 4B, Case 2) had an additional near-triploid aneuploid peak. Three of the adenomas (5.4%) had near-triploid aneuploid patterns. One of the patients with carcinoma (Figure 4A, Case 1) died, 32 months after initial diagnosis, of disease-related causes. The remaining patient with carcinoma (Case 2) had a 47-month disease-free interval. All of the patients with hyperplastic and adenomatous glands are free of disease, after a mean follow-up interval of 25 months. This study indicated that flow cytometric analysis of nuclear DNA content does not complement conventional pathologic methods in distinguishing between parathyroid gland chief cell hyperplasia, adenoma, or carcinoma; however, it did suggest the possibility that parathyroid adenomas and primary chief cell hyperplasias may contain a subset of tumors that could manifest biologic malignancy if allowed to progress untreated.     

A classification tree approach for pituitary adenomas

It is difficult to evaluate the recurrence and progression potential of pituitary adenomas at presentation. The World Health Organization classification of endocrine tumors suggests that invasion of the surrounding structures, size at presentation, an elevated mitotic index, a Ki-67 labeling index higher than 3%, and extensive p53 expression are indicators of aggressive behavior. Nevertheless, Ki-67 and p53 labeling index evaluation is subject to interobserver variability, and their cutoff values are controversial. In the present study, the prognostic value of Ki-67 and p53 protein labeling indices and their correlation with clinical and radiologic parameters were evaluated using digital image analysis in a series of 166 pituitary adenomas in patients having undergone a follow-up of at least 6 years to evaluate the impact on the recurrence and progression potential of pituitary adenomas. The data were analyzed using the receiver operating characteristic curve and classification and regression tree analysis. The results showed that, in the unstratified data set, the commonly used threshold of the Ki-67 index of 3% has a high specificity (89.5%) but a low sensitivity (53.8%). Unsatisfactory performance results were obtained by performing receiver operating characteristic curve analysis on the p53 labeling index. On the contrary, the classification and regression tree analysis-derived tree demonstrated that each pituitary adenoma subtype has specific prognostic factors. Specifically, the Ki-67 labeling index is a useful prognostic factor in nonfunctioning, adrenocorticotropin, and prolactin adenomas, but with different thresholds. In conclusion, our study emphasizes that the term pituitary adenomas includes different types of tumors, each one having specific prognostic factors.     

Low levels of apoptosis and proliferative activity in colorectal villous tumors: Comparison with tubular tumors

In order to clarlfy the cell kinetics of colorectal villous tumors (VT), 21 villous adenomatous areas and 12 carcinomatous areas within villous adenomas were investigated for proliferative activity and apoptosis and compared with a series of 41 tubular tumors (TT), demonstrating elements of intramucosal carcinomas as well as tubular adenomas (so-called carcinoma in tubular adenoma). Proliferation was estimated in terms of KI-67 labeling indices and mitotic indices, and apoptosis was assessed by DNA nick-end labeling to give apoptotic Indices. Apoptotic indices of villous adenomatous and carcinomatous regions were significantly lower than the values for their tubular counterparts. Kl-67 labeling indices were also significantly lower for adenoma components. Apoptotic indices, Ki-67 labeling indices and mitotic Indices increased with atypia raised in tubular adenoma components. Correlations of mitotic indices with apoptotic indices, Ki-67 labeling Indices with apoptotic indices and mitotic Indices with Ki-67 labeling indices were found for each villous tumor group and tubular tumor group, and the apoptosis and proliferation ratios for villous tumors were relatively low, suggesting a tendency for greater growth due to less cell deletion. Although this is only one of the biological features of villous tumor groups, it might play a major role in generation of malignancy.     

Immunohistochemical characteristics of duodenal adenomas in familial adenomatous polyposis with special reference to cell kinetics

The duodenum is the second most frequent site of cancer in patients with familial adenomatous polyposis (FAP). The main objective of this study was to evaluate the cell kinetics in duodenal and ampullary adenomas in FAP. The endoscopic and biopsy findings of duodenal adenomas in 22 FAP subjects and 18 non-FAP subjects were compared. Adenomas in FAP included 15 ampullary adenomas and 17 nonampullary adenomas. The cell kinetics was evaluated by immunohistochemistry for Ki-67, p53, bcl-2, and cyclooxygenase 2 (COX2), and the apoptotic index (AI) as determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method. Any correlations between the indices for cell kinetics and the endoscopic findings were identified. All 50 adenomas were histologically verified to be tubular adenoma with low-grade dysplasia. Neither the expression of Ki-67, p53, bcl-2, and COX2 nor the AI differed substantially between FAP and non-FAP subjects. In patients with FAP, duodenal adenoma tended to have a higher Ki-67-labeling index than the ampullary adenoma (54.3 +/- 11.3 versus 46.8 +/- 12.7; .05 < P < .1). In addition, the Ki-67-labeling index in endoscopically normal or slightly enlarged ampullary adenoma was significantly higher than that in markedly enlarged ampullary adenoma (51.8 +/- 11.4 versus 39.4 +/- 11.3; P < .05). Duodenal adenoma in FAP subjects was not found to have a higher proliferative activity or a smaller degree of apoptosis compared with those in non-FAP subjects. The smaller proliferative activity in larger ampullary adenoma may thus be related to the static nature of ampullary adenoma in FAP.