Assessment of cell proliferation in pathology--what next?

Vitamin E supplementation in chemical colorectal carcinogenesis: a two-edged knife

This work investigated the effects of Vitamin E (VE) on aberrant crypt foci (ACF) incidence, oxidative stress parameters (serum and hepatic VE concentration, and homocysteine, glutathione (GSH), and malondialdehyde (MDA) levels), and expression of both cyclooxygenase-2 (COX2) and proliferating cellular nuclear antigen (PCNA) in experimental colorectal carcinogenesis. Male Wistar rats received subcutaneous injections of 1,2-dimethylhydrazine (DMH) twice a week, for two weeks (40 mg/kg), except for the Control group. Animals were separated into groups that received different amounts of VE in the diet: 0 IU (0×), 75 IU (recommended daily intake, RDI), 225 IU (3× RDI), or 1500 IU (20× RDI), during (dDMH) or after (aDMH) administration of carcinogen. The 0×dDMH and 3×dDMH groups showed decreased serum VE levels. Hepatic VE concentration was higher in 3×aDMH as compared with the other groups. All the groups, except the Control and the 0×aDMH groups, had reduced GSH levels. The 0×dDMH, 0×aDMH, and 20×aDMH groups exhibited increased MDA levels. The aDMH groups had higher ACF incidence and PCNA expression. The 0×aDMH group presented higher ACF rate, followed by 20×aDMH. Moreover, the 3×aDMH group displayed reduced ACF incidence and COX2 expression. Multivariate analysis revealed that GSH modulated homocysteine levels and COX2. These results suggested that 1500 IU of VE is hazardous, whereas 225 IU of VE has beneficial effects on chemical colorectal carcinogenesis.

Expression and clinical significance of the proliferation marker minichromosome maintenance protein 2 (Mcm2) in diffuse astrocytomas WHO grade II

Background

The WHO classification system for astrocytomas is not considered optimal, mainly because of the subjective assessment of the histopathological features. Few prognostic variables have been found that stratify the risk of clinical progression in patients with grade II astrocytoma. For that reason there is a continuous search for biomarkers that can improve the histopathological diagnosis and prognostication of these tumours.

Aim

This study was designed to investigate the prognostic significance of the proliferative marker Mcm2 (minichromosome maintenance protein 2) in diffuse astrocytomas WHO grade II and correlate the findings with histopathology, mitoses, and Ki67/MIB-1 immunostaining.

Method

61 patients with histologically verified grade II astrocytoma (WHO 2007) were investigated. Paraffin sections were immunostained with anti-Mcm2, and the Mcm2 proliferative index (PI) was determined as the percentage of immunoreactive tumour cell nuclei.

Results

Mcm2 PI was not associated with any histopathological features but correlated significantly with mitotic count and Ki67/MIB-1 PI (p<0.05). In the survival analyses Mcm2 showed trends to poorer survival, however, statistical significance was not achieved in the univariate analyses (p>0.05).

Conclusions

In our hands Mcm2 immunostaining has no advantage over Ki67/MIB-1 in the evaluation of grade II astrocytomas. Larger studies are needed to fully clarify the prognostic role of this biomarker.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1715002791944037

Immunoexpression of angiogenesis, nitric oxide synthase, and proliferation markers in gingival samples of patients with aggressive and chronic periodontitis

BACKGROUND

In periodontal tissues, angiogenesis seems to be important for the maintenance of healthy tissues and in periodontal diseases. Angiogenesis is regulated through a complex interplay of molecular signals mediated by growth factors involving extracellular matrix remodeling, endothelial cell migration and proliferation, capillary differentiation and anastomosis. However, the influence of angiogenesis in the development, progression, and healing of periodontal lesions is currently under investigation. This immunohistochemical study evaluates the expression of vascular endothelial growth factor (VEGF), microvessel density (MVD), nitric oxide synthase (NOS) 1 and 3, and Ki-67 in gingival tissues of patients with aggressive and chronic periodontitis.

METHODS

Twenty-seven human gingival biopsies were taken from patients with chronic periodontitis (n = 14 patients), generalized aggressive periodontitis (n = 6 patients), and healthy periodontia (n = 7 patients). The specimens were immunohistochemically stained for VEGF, MVD, NOS 1 and 3, and Ki-67.

RESULTS

The levels of VEGF, MVD, NOS 1 and 3, and Ki-67 were found to be significantly different among groups (P >0.001). Patients with aggressive periodontitis had higher levels of these markers compared to those in patients with chronic periodontitis and healthy patients.

CONCLUSIONS

The analysis demonstrates a higher expression of all immunologic markers particularly in subjects with aggressive periodontitis. In summary, the data from this pilot investigation suggests that VEGF is an important factor in the pathogenesis of the aggressive and chronic forms of periodontitis.

The expression of the proliferation marker Ki-67 and oestrogen and progesterone receptors in the proximal and distal fallopian tube

Significant epithelial proliferation is identified more frequently in the fallopian tube in patients with ovarian tumours than in control patients. More extensive sampling of the fallopian tube is also associated with a more frequent identification of epithelial proliferation. We compared cellular proliferation at either end of the fallopian tube as detected with an antiserum to the Ki-67 protein. Variations in oestrogen and progesterone receptor proteins were also examined. Proliferative activity as expressed by the Ki-67 protein, and oestrogen receptor expression was greater in the proximal fallopian tube and progesterone receptor expression was greater in the distal fallopian tube. Only the difference in progesterone receptor expression was statistically significant (P =0.0431). This study indicates that variations in Ki-67, oestrogen and progesterone receptor protein expression occur at different sites in the fallopian tube. This should be taken into account when planning studies of epithelial cell proliferation in the fallopian tube in the future.

Evidence of increased cell proliferation in the hippocampus in children with Ammon's horn sclerosis

Previous studies of Ammon's horn sclerosis (AHS) suggest that AHS is both the result of and the cause of seizures, and support the idea that seizures cause alterations in cell numbers and location. To test the hypothesis that epilepsy induces neurogenesis/gliogenesis, hippocampal cell proliferation was assessed in AHS. Twelve and four resected hippocampi in patients with AHS and with tumor-related epilepsy (TRE), respectively, and 11 autopsy controls were immunostained for Ki-67. Total number of Ki-67-positive cells (KiPC) in each hippocampal area was counted. Selected cases were further studied with double immunohistochemical labeling. KiPC were observed in all three groups. Total numbers of KiPC were significantly higher in AHS cases than in controls, but were not significantly different between TRE cases and controls. Significant differences were observed in the dentate gyrus, the cornu ammonis (CA)-4 region, and the fissura hippocampi between the AHS and control groups. In double immunolabeling, nestin was positive in some KiPC. The existence of neurogenesis/gliogenesis was shown in the hippocampi of pediatric patients with AHS. Increased numbers of progenitor cells in the hippocampi with AHS appear not to be due to seizures per se, but to be more associated with the specific cause of epilepsy.

Proliferation and apoptosis of hippocampal granule cells require local oestrogen synthesis

Ovarian oestrogens have been demonstrated to influence neurogenesis in the dentate gyrus. As considerable amounts of oestrogens are synthesized in hippocampal neurones, we focused on the role of hippocampus-derived estradiol on proliferation and apoptosis of granule cells in vitro. We used hippocampal dispersion cultures, which allowed for cultivation of the cells under steroid- and serum-free conditions and monitoring of oestrogen synthesis. To address the influence of hippocampus-derived estradiol on neurogenesis, we inhibited oestrogen synthesis by treatment of hippocampal cell cultures with letrozole, a specific aromatase inhibitor. Alternatively, we used siRNA against steroidogenic acute regulatory protein (StAR). The number of proliferative cells decreased whereas the number of apoptotic cells increased dose-dependently, in response to reduced estradiol release into the medium after treatment with letrozole. This also held true for siRNA against StAR transfected cell cultures. Application of estradiol to the medium had no effect on proliferation and apoptosis whereas the anti-proliferative and pro-apoptotic effects of StAR knock-down and letrozole treatment were restored by treatment of the cultures with estradiol. Our findings suggest that neurogenesis and apoptosis in the hippocampus require a defined range of estradiol concentrations that is physiologically provided by hippocampal cells but not by gonads.

Immune processes in periodontal disease: a review

The inflammatory and immune processes in periodontitis are complex and, although a great deal of information is available, many questions remain. Variation in human susceptibility to periodontitis has long been accepted, but the pathological basis of this is poorly understood. Similarly, we know little of the differences, if any, between the pathology of chronic and aggressive periodontitis. Genetics and environmental influences play a role in the susceptibility process, but if and how that translates through the immune and inflammatory processes to produce the plasma cell-dominated lesions seen in periodontitis remain to be elucidated. This review will focus on immunological aspects of the inflammatory changes seen in gingivitis and periodontitis, addressing both humoral and cellular responses to the microbial insult from dental plaque. A tendency for an individual or site to form an extensive plasma cell infiltrate may indicate an inability to defend against periodontopathogens and thus a predisposition to periodontitis. The issues to be considered include: 1) homing of immune and inflammatory cells to target tissues; 2) their local proliferation and synthetic activity; 3) the cytokine profile of the leukocytes; 4) the immunoglobulin subclasses of locally produced antibodies; 5) mucosal and systemic immune characteristics of the response; 6) the humoral immune response in periodontal health and disease states; and 7) the antigenic target of the immune response in periodontal lesions.

Comparison between immunohistochemical expression of cyclin D1 and p21 and histological malignancy graduation of oral squamous cell carcinomas

The objective of the present study was to correlate the expression of cyclin D1 with the expression of p21 in 28 cases of oral squamous cell carcinoma (OSCC), as well as to compare the expression of both with a histological graduation of this neoplasm. Immunohistochemistry was used to obtain the expression of cyclin D1 and p21. The results of statistical analysis showed no correlation between the expression of cyclin D1 and p21. Also, there was no correlation between the mean numbers of cyclin D1 positive nuclei and p21 positive nuclei and the histological scores of malignancy. However, the marked expression of cyclin D1 in high-grade tumors supports its role in proliferative activity. In contrast, p21 seems unable to arrest tumor progression in OSCC.

Análise da imunoexpressão do PCNA e p53 em carcinoma de células escamosas oral: correlação com a gradação histológica de malignidade e características clínicas

OBJETIVO: Analisar a imunoexpressão das proteínas PCNA e p53 em carcinoma de células escamosas oral (CCEO) vislumbrando verificar uma possível correlação entre o escore de malignidade e os dados clínicos dos pacientes. MÉTODOS: Selecionou-se 14 casos de CCEO e classificando-os de acordo com uma adaptação do sistema de gradação histológica de malignidade proposto por Anneroth, Batsakis, Luna, enquadrando-se 7 casos como baixo escore de malignidade (Grupo I) e 7 casos como alto escore (Grupo II). As informações dos pacientes foram coletadas através de fichas clínicas e os dados tabulados. Realizou-se, então, o estudo imuno-histoquímico utilizando anticorpos monoclonais anti-PCNA e anti-p53, obtendo-se o índice de positividade (IP) em cada caso. RESULTADOS: Identificou-se um IP médio ao PCNA de 56,0% no Grupo I e 83,8% no Grupo II. Com relação à p53 o IP médio no Grupo I e no Grupo II correspondeu, respectivamente, a 41,2% e 41,4%. A análise estatística demonstrou correlação significativa entre o índice de células PCNA positivas e o escore de malignidade. Nenhuma outra correlação foi observada. CONCLUSÕES: O maior número de células PCNA positivas correlacionou-se com elevado escore de malignidade em CCEOs, sugerindo maior atividade proliferativa nestas lesões, entretanto, tal correlação não se estabeleceu quando da análise da imunoexpressão da p53.

Immunocytochemistry of myoepithelial cells in the salivary glands

MECs are distributed on the basal aspect of the intercalated duct and acinus of human and rat salivary glands. However, they do not occur in the acinus of rat parotid glands, and sometimes occur in the striated duct of human salivary glands. MECs, as the name implies, have structural features of both epithelial and smooth muscle cells. They contract by autonomic nervous stimulation, and are thought to assist the secretion by compressing and/or reinforcing the underlying parenchyma. MECs can be best observed by immunocytochemistry. There are three types of immunocytochemical markers of MECs in salivary glands. The first type includes smooth muscle protein markers such as alpha-SMA, SMMHC, h-caldesmon and basic calponin, and these are expressed by MECs and the mesenchymal vasculature. The second type is expressed by MECs and the duct cells and includes keratins 14, 5 and 17, alpha 1 beta 1 integrin, and metallothionein. Vimentin is the third type and, in addition to MECs, is expressed by the mesenchymal cells and some duct cells. The same three types of markers are used for studying the developing gland. Development of MECs starts after the establishment of an extensively branched system of cellular cords each of which terminates as a spherical cell mass, a terminal bud. The pluripotent stem cell generates the acinar progenitor in the terminal bud and the ductal progenitor in the cellular cord. The acinar progenitor differentiates into MECs, acinar cells and intercalated duct cells, whereas the ductal progenitor differentiates into the striated and excretory duct cells. Both in the terminal bud and in the cellular cord, the immediate precursors of all types of the epithelial cells appear to express vimentin. The first identifiable MECs are seen at the periphery of the terminal bud or the immature acinus (the direct progeny of the terminal bud) as somewhat flattened cells with a single cilium projecting toward them. They express vimentin and later alpha-SMA and basic calponin. At the next developmental stage, MECs acquire cytoplasmic microfilaments and plasmalemmal caveolae but not as much as in the mature cell. They express SMMHC and, inconsistently, K14. This protein is consistently expressed in the mature cell. K14 is expressed by duct cells, and vimentin is expressed by both mesenchymal and epithelial cells. After development, the acinar progenitor and the ductal progenitor appear to reside in the acinus/intercalated duct and the larger ducts, respectively, and to contribute to the tissue homeostasis. Under unusual conditions such as massive parenchymal destruction, the acinar progenitor contributes to the maintenance of the larger ducts that result in the occurrence of striated ducts with MECs. The acinar progenitor is the origin of salivary gland tumors containing MECs. MECs in salivary gland tumors are best identified by immunocytochemistry for alpha-SMA. There are significant numbers of cells related to luminal tumor cells in the non-luminal tumor cells that have been believed to be neoplastic MECs.

Ki-67 labeling is correlated with the time to recurrence in primary glioblastomas

The Ki-67 labeling index (LI) was shown in many cut-off studies to be significantly correlated to the postoperative survival probability in gliomas in univariate and multivariate analyses. However, a direct relationship of the Ki-67 LI and the growth fraction, respectively, to clinical growth parameters was not demonstrated in a single tumor type of this group until now. We compared the Ki-67 LI of 20 primary glioblastomas and their recurrent tumors with the time to reoperation for recurrence. Regression analyses showed (1) a high reproducibility of the LIs at the second versus the first operation corresponding to an inherent growth potential of a given individual tumor and (2) a strong inverse correlation of LI to time to recurrence (TR) (r = -0.92). Additionally to a lower LI (corresponding to a smaller growth fraction), a longer cycle time could be derived in slowly growing as compared to rapidly growing tumors. A direct relationship of the Ki-67 LI to a clinical time parameter (the TR) was obtained, and a predictive significance of individual LIs in glioblastomas could be defined.

Prognostic comparative study of S-phase fraction and Ki-67 index in breast carcinoma

AIMS

To investigate the prognostic value of recently proposed flow cytometric S-phase fraction (SPF) variables (average SPF and SPF tertiles) compared with conventional SPF, and to compare the one with the best predictive value with the immunohistochemical Ki-67 index in breast carcinoma.

METHODS

A short term follow up study (median, 39.6 months) of a large series of patients (n = 306) was conducted. DNA ploidy was analysed on fresh/frozen tumour samples by flow cytometry, and the SPF was calculated from the DNA histogram using an algorithm. The Ki-67 index was assessed on paraffin wax embedded material by immunohistochemistry (cut off point, 10%). The two methods were compared by means of kappa statistics, and the prognostic significance of both in relation to disease free survival (DFS) and overall survival (OS) was determined.

RESULTS

SPF and Ki-67 analysis was performed on 234 (76.5%) and 295 (96.4%) tumours, respectively. The two assessments were simultaneously available in 230 cases. All SPF variables analysed in the whole series significantly correlated with disease evolution, with the conventional median SPF (cut off point, 6.1%) showing the highest predictive value in relation to both DFS (p = 0.0001) and OS (p = 0.0003). SPF tertiles and median SPF evaluated according to DNA ploidy status had no prognostic significance. The Ki-67 index showed a trend in relation to DFS (p = 0.086) that did not reach significance, and no correlation with OS was found (p = 0.264). The comparative analysis of SPF and Ki-67 revealed some agreement between the two methods (agreement, 69.13%; kappa statistic, 0.3844; p < 0.001), especially in the subgroup of diploid tumours.

CONCLUSIONS

Flow cytometric SPF is a better prognosticator than the Ki-67 index, but only SPF variables applied in the whole series show potential clinical usefulness.

Clinical, pathological and immunological aspects of periodontal disease

The inflammatory and immune responses during the development and progression of periodontitis are reviewed. Susceptibility to periodontitis may be related to whether plasma cells predominate in the tissues of an individual, or a site, in response to the microbial insult from dental plaque. The tendency for an individual or site to form an extensive plasma cell infiltrate may indicate an inability to defend against periodontopathogenic bacteria and thus a predisposition to periodontitis. Selected pertinent areas of current interest in cellular and humoral immunology are considered within the periodontal context. These topical issues include (a) homing of immune and inflammatory cells to target tissues; (b) the local proliferation and synthetic activity of immune and inflammatory cells; (c) the cytokine profile of the inflammatory and immune cells; and (d) the immunoglobulin subclasses of locally produced antibodies.

Apoptosis in cervical squamous carcinoma: predictive value for survival following radiotherapy

BACKGROUND

Apoptosis, or programmed cell death, can be induced by radiotherapy. The extent of apoptosis in a tumour before treatment may have important implications for response to radiotherapy and long term survival.

AIM

To examine the extent of apoptosis in tumour tissue from patients with squamous carcinoma of the cervix before radiotherapy, and to correlate this with response to treatment and prognosis.

METHODS

The percentage of apoptotic cells was assessed in 146 carcinomas of the cervix from patients scheduled to receive radiotherapy. The CAS 200 static image analysis system was used to count the number of tumour nuclei per high power field, while the numbers of apoptotic cells in the same field were visualised simultaneously on the image analyser and recorded manually.

RESULTS

The median apoptotic level was 0.73%. Patients were divided into two groups around the median. There was no statistically significant difference in outcome between the two groups as determined by long term survival following radiotherapy.

CONCLUSIONS

The CAS 200 static image analyser system can be used to assist in the rapid semiautomated assessment of apoptosis in conventionally prepared tissue. The results suggest that the apoptotic state of a tumour before treatment is of no value in predicting response to radiotherapy and subsequent prognosis. Tumour stage, size, and BrdU labelling index, as a measure of proliferation rate, remain the most important prognostic factors in terms of predicting local tumour control.

Cell synthesis, proliferation and apoptosis in human dental periapical lesions analysed by in situ hybridisation and immunohistochemistry

OBJECTIVE

The role of structural and host defensive cells in periapical lesions has been assessed previously by morphometric and immunohistochemical studies. The aim of this study was to investigate the function of peri- apical cells by employing molecular techniques to estimate the cell synthetic activity, proliferation and apoptosis in these lesions. We specifically sought answers to the following questions. Which cells of the periapical lesions are quiescent or actively synthesising proteins? Do immune cells proliferate in this region in the same way as epithelial cells proliferate? Furthermore do cells in peri- apical lesions undergo apoptosis, and if so which cells exhibit this programmed cell death?

MATERIALS

Twenty-five periapical tissue samples (15 granulomas and 10 radicular cysts) were assessed. Poly-adenosine (poly (A)) RNA and ribosomal RNA (rRNA) bearing cells in formalin-fixed/paraffin-embedded peri- apical tissues were analysed by in situ hybridization (ISH) using digoxigenin-labelled oligo d (T) and 28S rRNA probes respectively in order to estimate cell synthetic activity. Furthermore, S-phase proliferating and cycling cells were examined by ISH using a histone probe and Ki-67 immunostaining so as to assess cellular proliferation. Mononuclear cells were further differentiated by immunohistochemistry (IHC) as T cells, B cells and macrophages. Apoptotic cells were determined by in situ end-labelling methodology for detecting fragmented DNA.

RESULTS

Poly (A) RNA (mostly messenger RNA) and 28S rRNA-expressing cells were detected in all samples. Plasma cells exhibited strongest staining for the two probes, with slight to moderate staining found in the epithelium, fibroblasts, macrophages, endothelial cells and lymphocytes, whereas almost all polymorphonuclear leucocytes (PMN) were negative for these probes. A few histone mRNA-expressing cells were detected in basal and suprabasal epithelial cells and mononuclear cells in 15/25 cases but their reactivity was weak. Ki-67 positive cells were found in all samples and their numbers were generally higher than histone mRNA positive cells. Apo- ptotic cells were detected in 23/25 cases and the majority of apoptotic cells were PMN which were engulfed by large cytophagocytic macrophages.

CONCLUSION

This study indicates that in dental periapical lesions, apoptosis occurs predominantly in PMN. It is evident that most cells apart from PMN are exhibiting synthetic activity but only epithelial cells undergo proliferation which implies that immune cells must proliferate at distant lymph nodes and travel to the periapical lesion rather than proliferating within the lesion. These results suggest considerable advantages in estimating gene expression within cells in addition to the immunohistochemical detection of cells to determine cell activity at inflamed sites. Clearly, functional cell synthetic activity, resolution and clearance systems operate in peri- apical cystic and granuloma lesions.

Ki-67, oestrogen receptor, and progesterone receptor proteins in the human rete ovarii and in endometriosis

AIM

To examine proliferative activity using the Ki-67 protein, oestrogen receptor protein, and progesterone receptor protein expression in the rete ovarii, and to make comparisons with their expression in endometriosis.

METHODS

Immunohistochemistry was used to study the rete ovarii in 24 cases and endometriosis in seven cases, using antibodies to Ki-67 protein (growth fraction (GF) quantified using a point score method) and oestrogen receptor and progesterone receptor (quantified using the H score method).

RESULTS

There was no evidence of a significant difference in the Ki-67 protein, oestrogen receptor, and progesterone receptor in the rete ovarii in different phases of the menstrual cycle (proliferative phase: GF = 1.052, oestrogen receptor H score = 13.4, progesterone receptor H score = 15.32; secretory phase: GF = 0.736, oestrogen receptor H score = 7.5, progesterone receptor H score = 1.84). The expression of all three proteins was greater in the foci of endometriosis (GF = 6.99, oestrogen receptor H score = 152.02, progesterone receptor H score = 127.36) than in the rete ovarii (p < 0.0005-0.0008, Mann-Whitney U test).

CONCLUSIONS

There is a low rate of cellular proliferation in the rete ovarii and this structure shows less responsiveness to hormone stimulation than foci of endometriosis. These differences may provide a useful tool to distinguish the rete ovarii from endometriosis in cases of diagnostic difficulty.

Proliferative status of cells in adult human dentate gyrus

Experiments in rodents and marmoset monkeys indicate that granule neurons of the dentate gyrus may be renewable throughout the entire life of the animal. Whether this occurs in larger primates remains a matter of contention. However, a recent study of brain samples from five adult humans who had been injected with the thymidine analog bromodeoxyuridine indicates that new neurons might indeed be produced in the dentate gyrus. In this study, hippocampus specimens removed from 18 adult humans for treatment of epilepsy were examined. The cell cycle marker Ki67, which is expressed from late G1 to M phase, was demonstrated by immunohistochemistry, and H2b/H3/H4 histone mRNAs, which are expressed during S phase, were demonstrated by in situ hybridization. Only 0.17% of cells in the subgranular layer, the site of neuronal progenitor cells, were Ki67 immunoreactive but the identity of these could not be proven. Although the histone in situ hybridization technique was shown to work in human fetal brain, no M phase cells could be demonstrated in the hippocampus. The generation of new granule neurons in the human hippocampus must occur at a very slow rate. The approaches used in this study are likely unsuitable for studying cell populations with low turnover rate. Further work is needed to determine the fate of newly generated cells in the dentate gyrus. This information is of importance to our understanding of the mechanisms of learning and memory.

Apoptotic index as a prognostic factor in Hodgkin's disease

Hodgkin's disease (HD) is an unusual malignant neoplasm, mainly because of the rarity of tumor cells in the diseased tissues, but also due to a relatively favorable response to treatment. In a previous study, we have shown a variable degree of apoptosis in lymph nodes from HD patients. We now looked for clinicopathological correlations of apoptosis with special emphasis on the prognosis in this disease. A retrospective study of 92 patients was carried out, using in situ end labelling of DNA fragments and an apoptosis detection kit. An apoptotic index (Al) was calculated in each case, as the percentage of apoptotic Hodgkin-Reed-Sternberg cells out of the total number of tumor cells in 10 selected high power fields. An association between a high Al and advanced stages was noted. A Kaplan-Meier analysis showed a negative correlation between Al and survival (p=0.05). In a multivariable analysis adjusting for Ann Arbor stage, a high Al carried a 3.27 fold risk of dying of HD (OR=3.27; Cl=0.89-11.94). However, in our limited cohort of HD patients, Al was not an independent prognostic factor. The results of this study confirm the important role played by apoptosis in HD and suggest that the apoptotic index is probably a negative prognostic marker in this disease. Its assessment in patients with HD may provide a new, important clinical tool.

Dynamics of parenchymal cell division, differentiation, and apoptosis in the young adult female mouse submandibular gland

The submandibular salivary gland of the young adult female mouse has two secretory cell types, acinar and granular duct, which are separated by intercalated ducts. Based on the occurrence of autologous cell division in these cells, they have been traditionally classified as expanding populations. However, differentiation from stem or progenitor cells in the intercalated ducts, usually associated with renewing populations, has also been detected. The question of renewing or expanding populations is resolved by quantitating and integrating the rates of autologous cell division, differentiation, and apoptosis for each cell type. The integrated data shows that both acinar and granular duct cell populations exhibit a substantial positive growth index, whereas the growth index for the intercalated duct cells is moderately negative. On balance, it suggests that the submandibular gland of the young adult female mouse is still growing. Comparison of young female mice with older females suggests that, although overall parenchymal growth slows with age, there is no longer a net loss of intercalated duct cells. Comparison with young adult male submandibular glands indicates that gender differences exist in the rates and mechanisms used for maintaining the different cell populations. The acinar and granular duct cell populations in young adult female mouse submandibular glands are expanding at the expense of the intercalated duct cell population, which appears to be contracting.

Perspective: defects in cell cycle control and cancer

The past several years have witnessed a dramatic accumulation of experimental and clinical evidence supporting the notion that the cell cycle machinery is commonly targeted on oncogenesis. While numerous cell cycle regulators qualify as proto-oncogenes or tumour suppressors and their aberrations may provide direct proliferative advantage to cancer cells, defects in checkpoint mechanisms act more indirectly yet affect both tumour progression and response to anticancer therapy. In this review, the ways that cell cycle defects contribute to oncogenesis are briefly illustrated and the emerging benefits of the newly gained insights into the cell cycle clock for clinical oncology are critically considered. Given the many reviews on the subject, emphasis is put on concepts rather than comprehensive treatment of the selected topics, with particular attention given to controversial issues, unorthodox phenomena, and the challenge facing the 'cell cycle and cancer field' at the transition to the next millennium.

p53, PCNA and Ki-67 expression in oral squamous cell carcinomas: the vagaries of fixation and microwave enhancement of immunocytochemistry

Proliferation markers are widely used as indicators of tumour progression and aggression. Fixation and antigen retrieval methods may enhance the immunocytochemical sensitivity of these markers but may also lead to loss of specificity. As these methods are often used quantitatively, standardisation of internal and external methodology is paramount. This study aimed to compare the effects of alcohol and formalin fixation and of microwaving on the immunocytochemical demonstration of p53, PCNA and Ki-67 in oral squamous cell carcinoma using duplicate tissue blocks from 24 cases. Both qualitative and quantitative differences in antigen expression were revealed. Whilst alcohol fixation alone at least maintained and usually increased the strength of positive staining, microwaving alcohol-fixed sections often gave rise to non-specific staining. p53 staining following microwave enhancement of alcohol-fixed tissue showed a significant incidence of conversion of negative results to positive and of positive staining in unexpected tissue components. Alcohol fixation increased the sensitivity of PCNA detection with a far less dramatic loss of specificity. The results emphasise the need for careful standardisation of immunocytochemical methods, particularly when used quantitatively and for inter-laboratory comparisons.

p53 expression in skin carcinogenesis and its relationship to cell proliferation and tumour growth

The immunoreactivity of p53 protein was studied in relation to tumour development, histopathological characteristics, cell proliferation, and basement membrane organisation following the induction of skin carcinogenesis in tumour-sensitive and -resistant mouse strains by ultraviolet (UV) irradiation or 7,12-dimethylbenz(a)anthracene (DMBA). In non-neoplastic skin exposed to UV irradiation or DMBA, p53 immunoreactivity was observed in nearly 50% of the basal layer cells. These cells were morphologically and histochemically indistinguishable from the p53-negative cells, occurring similarly in the tumour-producing and the tumour-negative mouse strains and regardless of subsequent tumour formation. In induced epidermal hyperplasia and in benign tumours, p53-positive and proliferating cells constituted 40-50% of all cells in the basal layer, while superficial cells were p53 negative. In dysplastic epidermis, p53-positive cells and proliferating cells were seen in all cell layers. In the case of squamous cell carcinomas, p53-positive proliferating cells in differentiated neoplasms were localised close to the basement membrane and, more frequently, in border areas showing invasion and basement membrane destruction. In horn cysts, centrally located cells were non-proliferating and p53 negative. In moderately differentiated neoplasms, proliferating cells were located closer to the basement membrane, while p53-positive cells were distributed diffusely in the neoplasm. In poorly differentiated neoplasms, p53-positive cells were more common than proliferating cells and were arranged in a diffuse pattern. The results showed that the number and location of p53-positive cells depended upon histology, with a close relationship to tumour type and degree of malignancy, but not on the mode of induction, nor on the animal strain or the relationship to subsequent tumour formation.

Cellular kinetic differences between Hodgkin's and anaplastic large cell lymphomas: relation to the expression of p34cdc2 and cyclin B-1

Our study was designed to compare cellular kinetic parameters of classical Hodgkin's disease (HD) with those of anaplastic large cell lymphomas (ALCL-C, common type; and ALCL-HL, Hodgkin's like), with a particular focus on the G2/M transition. These disorders share some phenotypic properties, e.g., CD30 positivity of putative neoplastic cells. The percentages of cells expressing p34cdc2 (p34) and cyclin B-1 (cyclin-B), which form a complex (maturation/mitosis promoting factor, MPF) regulating the G2-M phases of the cell cycle, were also registered. Highly significant differences between HD and ALCL-C were recognized: a) in HD, evidence for abortive mitosis (i.e., difficulty to proceed beyond the metaphase stage) and consequent multinucleation and/or deletion of CD30+ cells was prominent, in contrast to ALCL-C. This was associated with a markedly lower fraction of large atypical cells (LAC) expressing cyclin-B in the cytoplasm and the nucleus (C + N) in HD than in ALCL-C; b) the extent of multinucleation of CD30+ cells in HD, but not in ALCL-C, was correlated with the %p34+ LAC; c) the proportions of LAC expressing p34 and/or cyclin-B (C) were positively related to the percentages of cyclin-B (C + N)+ LAC in ALCL-C but not in HD; d) in HD, in contrast to ALCL-C, the size of the fraction of cyclin-B (C + N)+ LAC did not correlate with the ana/telophase indices (ATI, reflecting successful completion of mitosis) and the magnitude of cell loss; e) in ALCL-C, the percentages of p34+ LAC were positively correlated with ATI or the degree of CD30+ cell deletion, but inversely in HD. With regard to all parameters mentioned above, ALCL-HL tended to take an intermediate position between HD and ALCL-C, but sided more with the latter. In conclusion, our present results suggest a derangement of MPF kinetics and functions that is more profound in HD than in ALCL-C.

Correlations between mitotic and apoptotic indices, number of interphase NORs, and histological grading in squamous cell lung cancer

Proliferative activity of tumors is strongly associated with prognosis and response to therapy. The reason for faster and uncontrolled growth rate of tumors compared with normal tissue may be caused by the greater proliferation of cells, the smaller rate of cell death, or both. Cell production vs. cell loss rates, and their correlation with a grade of tumor cell differentiation (G) was estimated in 45 cases of squamous cell lung cancers (SCLC) by the use of mitotic indices (MI), number of interphase NORs, and apoptotic indices (AI) as parameters. The mitotic figures as well as apoptotic cells were observed on paraffin sections (4-microm thick) stained with haematoxylin and eosin, and with Feulgen reaction with Schiff-type reagent containing 0.5% Toluidine Blue. According to our results, all three parameters distinguish significantly (P < 0.05) between well and moderately or poorly differentiated groups, but not between the first two groups, and clearly discriminate between low- and high-grade malignancy. These results suggest classification of squamous cell lung cancers into two groups, a group of low and a group of high proliferative activity, despite their morphological appearance. Regression analysis revealed a significant (P < 0.0005) correlation between MI and AgNOR counts per cell nucleus as proliferative markers and AI as a marker of cell loss. The number of mitoses and apoptoses, especially when they are expressed as a percentage of the total number of tumor cells, are markers of tumor proliferation rate. They both can be used in biofunctional staging, based on cell kinetics, to provide more prognostic information about lung cancers than clinicopathological staging.

Pretreatment pathologic prognostic factors in head and neck squamous cell carcinoma

Squamous carcinomas of the head and neck region are a common problem for the otolaryngologist; surgeons are obliged to draw together disparate lines of evidence-from physical examination, pathology, and radiology-to plan optimal therapy for their patients. This article explores some of the ways in which pathologic analysis of a biopsy specimen in the past (determination of extent of invasion and degree of differentiation), present (including an analysis of the pattern of infiltration and the tumor' s DNA content), and, perhaps, the future (possibilities including cytogenetics and analysis of discrete steps in the cell cycle) plays a role in this process.

Proliferating cell nuclear antigen as a marker of cell kinetics in aberrant crypt foci, hyperplastic polyps, adenomas, and adenocarcinomas of the human colon

BACKGROUND

One of the first steps in multistage colonic carcinogenesis is increased cell proliferation and an upward shift of the proliferation zone of colonic crypts. In the present study, progression in cell kinetics was followed up at all sequential stages of colonic carcinogenesis, starting with aberrant crypt foci (ACF), the earliest putative preneoplastic lesions, hyperplastic and dysplastic polyps, and invasive carcinomas.

MATERIALS AND METHODS

Colonic tissue and tumor specimens were prospectively obtained from 65 patients treated at our hospital for adenocarcinoma or malignant polyps. For identification of ACFs, dissected mucosal strips obtained from patients with colorectal cancer were stained with 0.1% methylene blue and scanned under dissecting microscope. Paraffin-embedded ACFs and macroscopic lesions were serially sectioned, deparaffinized, and stained with a monoclonal antiproliferating cell nuclear antigen (PCNA) antibody. The PCNA-labelling index (PCNA-LI), expressed as a ratio of positively stained nuclei to total nuclei counted, was calculated separately for basal, middle, and upper colonic crypt compartments. A comparison of the PCNA-LI was made for each compartment in normal mucosa, and hyperplastic and dysplastic lesions.

RESULTS

A stepwise increase in the PCNA-LI was observed during neoplastic progression of colonic lesions. The two most important variables of increased cell proliferation, expressed as PCNA-LI per crypt compartment, were the presence of dysplasia and the size of dysplastic lesions.

CONCLUSIONS

In colorectal carcinogenesis, hyperproliferation with upward expansion of proliferative compartment is a characteristic feature at all stages of malignant progression.

Apoptosis in colorectal carcinoma occurring in patients aged 45 years and under: relationship to prognosis, mitosis, and immunohistochemical demonstration of p53, c-myc and bcl-2 protein products

The aim of this study was to ascertain whether apoptotic counts have prognostic significance in colorectal cancer and if such counts are related to the expression of proteins implicated in cell cycle regulation. Material from a cohort of patients aged 45 years or less with colorectal carcinoma was re-examined to determine apoptotic and mitotic counts by light microscopy, in addition to assessing p53, c-myc, and bcl-2 protein status by immunohistochemistry. The apoptotic index in the 74 patients who were alive or who had died of colorectal carcinoma ranged from 1.2 per cent to 12.3 per cent and exhibited independent prognostic significance, with high counts predicting better survival (P = 0.02). Mitotic counts were not related to survival, despite a close correlation with apoptosis (r = 0.85). Tumours regarded as not staining with the CM1 antibody for p53 protein demonstrated higher apoptotic counts, compared with those that stained (medians 5.2 and 4.0 per cent, respectively; P = 0.03), but p53 expression was found not to be related to survival. The 68 tumours which stained for c-myc appeared to exhibit higher mitotic counts than those that did not. bcl-2 was detected in only four tumours. The latter two proteins exhibited no apparent relationship to the apoptotic index or survival. Although these results indicate a potential role for apoptotic counting in prognostic prediction in colorectal tumours, this is an uncommon group of patients who exhibited some atypical features. The likelihood of a proportion of cases arising within hereditary non-polyposis colorectal cancer syndrome may limit the application of the findings to a more general population with cancer of the colon and rectum. Further work is required, including critical measurement of reproducibility and assessment of the relative impact of this parameter compared with 'traditional' prognostic markers.

A high apoptotic index occurs in subtypes of endometrial adenocarcinoma associated with a poor prognosis

A study was carried out to determine the apoptotic index (AI) in cases of endometrial adenocarcinoma that are usually associated with a poor prognosis, and to identify in the AI in these cases differs from the AI's in grade I and II endometrial adenocarcinoma. The apoptotic index (defined as the percentage of morphologically identified apoptotic cells and apoptotic bodies in counting 3000 tumor cells) was calculated for five grade III endometrial adenocarcinomas of no specific type (NST), five clear cell adenocarcinomas (CCC), three high grade uterine papillary serous carcinomas (UPSC) and one undifferentiated carcinoma of the endometrium. Overall a higher mean AI (6.3%) was identified in these poor prognosis neoplasms than in 13 grade I and II endometrial adenocarcinomas (mean AI 2.7% p < 0.0001). The apoptotic index was highest in the undifferentiated carcinoma (AI = 9.7%). The mean AI for the cases of UPSC, CCC and grade III endometrioid (NST) adenocarcinomas were 7.4%, 5.9% and 5.2% respectively. There was no evidence of a statistically significant difference in the AI in these poor prognosis groups (Kruskall Wallis test p = 0.45). Although the results show that a high AI is a feature of poor prognosis endometrial carcinoma, no distinction in AI was demonstrated in the subtypes examined.

Apoptosis in atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma

Explanations for the disparate behavior of atypical fibroxanthoma (AFX) as compared with pleomorphic malignant fibrous histiocytoma (MFH) have included the proposition that the former is a pseudosarcoma. Nonetheless, these tumors are now widely regarded as the same process, but with AFX behaving benignly by virtue of its superficial location. However, a neoplasm's metastastatic potential has been proposed to be related to apoptosis. Therefore, the aim of the present study was to examine apoptotic counts, in conjunction with two important regulators of apoptosis: p53 and bcl-2, to determine if a distinction exists that may account for the different outcomes of these lesions. There was no significant statistical difference between eight AFX and nine pleomorphic MFH in terms of apoptotic behavior, proliferative indexes, p53 protein expression, or presence of bcl-2 product. Therefore, our results further support the contention that AFX should be regarded as a form of pleomorphic MFH, which demonstrates low malignant potential by virtue of its location in readily accessible sites.

Structure, growth and cell proliferation of human osteosarcoma and malignant fibrous histiocytoma xenografts in serial transplantation in nude mice

Tumour specimens from one patient with osteosarcoma and one with malignant fibrous histiocytoma were transplanted in serial passages in nude mice. Structure, growth and cell kinetics of the xenografts were studied in order to assess the validity of the two tumour models. Cell proliferation was analysed using in vivo labelling with the thymidine analogue iododeoxyuridine (IdUrd) and the IdUrd labelling index (LI) was determined by immunohistochemistry. The DNA index (DI) was examined by flow cytometry. The c-myc oncoprotein expression was studied by immunohistochemistry. More intense proliferation was observed in the peripheral parts of the tumours. There was no correlation between tumour growth and cell proliferation in the two tumour groups. Stability of the tumour models was indicated by low intrapassage and interpassage variations of DI, LI, and volume doubling time, and also by retained histopathological characteristics and c-myc staining patterns of donor patients' tumours during serial transplantation.

Nuclear autoantigen p330d/CENP-F: a marker for cell proliferation in human malignancies

p330d, also known as CENP-F, is a newly characterized cell cycle specific nuclear autoantigen which is associated both with the centromeres and the nuclear matrix. It is expressed in low amounts in G0/G1-cells and accumulates in the nuclear matrix during S-phase with a maximum expression in G2/M-cells. In the present study we have investigated if p330d/CENP-F could be used as a marker for proliferation in different human malignancies. A flow cytometric method was developed by which p330d/CENP-F expression and DNA-content could be assessed on hematopoietic and solid tumors. Twenty-four different human hematopoietic malignancies, 12 breast cancers, and several cell lines were analyzed and the number of p330d/CENP-F positive cells and the S-phase fraction were determined. The percentage of p330d/CENP-F positive cells correlated with the fraction of S-phase cells in all human malignancies tested. Various cell lines revealed a similar cell cycle specific distribution. The association of p330d/CENP-F with the nuclear matrix facilitated the flow cytometric analysis of this protein due to its resistance to different preparation and fixation procedures. In summary, p330d/CENP-F seems to be a potentially valuable proliferation marker which can be applied to different tumors.

In situ localization of cell synthesis and proliferation in periodontitis gingiva and tonsillar tissue

OBJECTIVE

Previous work indicates that large numbers of B and T cells accumulate in the periodontal soft tissues although we know little about cellular synthetic activity and proliferation in this site. The aim of this study was to examine lymphocytic cell synthetic activity and proliferation in periodontitis gingiva and compare this to a known site of leucocyte proliferation, namely the oropharyngeal tonsils.

MATERIALS AND METHODS

Messenger RNA (mRNA) and 28S ribosomal (28S rRNA) expressing cells in formalin-fixed/paraffin-embedded gingival and tonsillar tissue sections were detected by in situ hybridisation (ISH) using poly-deoxyribothymidine and 28S probes respectively. In addition S-phase proliferating and cycling cells were also detected by ISH with histone probes and by Ki-67 immunohistochemistry. Ten gingival biopsy samples were obtained from adult periodontitis patients and five tonsillar biopsies from tonsillectomy patients.

RESULTS

Both mRNA and 28S rRNA-expressing cells were detected in all the samples tested. Plasma cells showed the strongest signal for the two probes and slight to moderate staining could be seen in epithelium, fibroblasts and endothelial cells. In contrast, gingival lymphocytes were either weakly stained or were unstained for these probes of synthetic activity. In tonsils, most lymphocytes in germinal centres showed moderate staining and mantol zone cells were much more weakly stained. In gingival samples, histone mRNA-expressing and cycling (Ki-67) cells were detected in 4/10, 10/10 cases respectively. These positive cells were mainly basal and suprabasal epithelial cells and a few mononuclear cells, whereas most germinal centre lymphocytes (B cells) were positive for this probe. The number of Ki67 positive cells was greater than histone mRNA bearing cells both in gingiva and tonsillar tissue. In contrast, mantol zone cells (mainly T cells) were sparsely stained by probes of cell proliferation.

CONCLUSION

These results indicate that local proliferation of B cells does not occur in periodontitis gingiva in contrast with tonsillar tissue, although plasma cells showed strong synthetic activity in both tissues. T cells did not appear to proliferate greatly nor undergo active synthesis in either of these tissues. These findings substantiate previous hypotheses that specific leucocytes predominate in the gingival tissue through selective homing rather than by local proliferation.

Ki-67 expression in early prostate cancer and associated pathological lesions

AIM

To assess cell proliferation in early prostate cancer and associated pathological lesions.

METHODS

Using the Ki-67 antibody, the cell proliferation index was measured in early stage prostatic carcinoma in 37 incidental tumours diagnosed at transurethral prostatectomy (TURP) and in 20 low volume cancers treated by radical prostatectomy. Proliferation indexes have also been measured in areas of normal peripheral zone, transition zone hyperplasia, atrophic appearing lobules, and high grade prostatic intraepithelial neoplasia in the radical prostatectomy cases.

RESULTS

In the TURP series the proliferation index correlated with grade and stage. Logistic regression analysis, however, showed that Gleason grade was the most reliable predictor of biopsy proven residual disease and clinical progression. In the radical series transition zone carcinoma the proliferation index was half that of peripheral zone carcinoma. The atrophic lobules also showed a high proliferation index of the same order as seen in the peripheral zone carcinoma. Normal peripheral zone showed the lowest proliferation index and in hyperplastic transition zone it was also less than the other areas.

CONCLUSIONS

There is only limited support for the correlation of proliferation index with grade in early stage prostatic carcinoma. The findings do not suggest that proliferation index adds to the prognostic information given by grade and stage in pT1 disease. The significant difference in proliferation index in transition zone and peripheral zone carcinomas supports the morphological distinction of these tumour types and is consistent with differences in biological behaviour. The high proliferation index in lobules considered morphologically atrophic is reminiscent of previous observations in which carcinoma was spatially associated with atrophy.

Cyclin D1 in astrocytic tumours: an immunohistochemical study

Forty-eight astrocytic tumours were stained immunohistochemically with antibodies to the cell cycle-regulating protein, cyclin D1, and to the proliferation marker MIB1 (Ki-67) using formalin fixed paraffin embedded tissue and a microwave antigen retrieval system. Cases were classified by the WHO system (1993). The labelling indices (LI) for both antibodies were compared with each other and with the tumour type. The mean labelling indices for both antibodies increased with the degree of malignancy, and a significant difference was seen between the pilocytic astrocytoma and diffuse astrocytoma together vs anaplastic astrocytoma and glioblastoma together. However, within each tumour type there was considerable variation in the labelling indices and a clear cut off value could not be demonstrated. There was a strong positive correlation between labelling indices for cyclin D1 and MIB1 in diffuse astrocytoma, but this correlation broke down increasingly in anaplastic astrocytoma and glioblastoma. There was poor correlation between cyclin D1 and MIB1 in pilocytic astrocytoma, a feature which appeared to separate them from the diffuse astrocytoma. Average labelling indices for cyclin D1 were higher than those of MIB1, which suggests that cyclin D1 positive cells represent a pool of cells from which proliferation and hence MIB1 expression can take place. In conclusion, cyclin D1 is overexpressed in astrocytic tumours, more so with increasing grade of malignancy and in a way which approximately correlates with MIB1 expression.

Comparative evaluation of p53-protein expression and the PCNA and Ki-67 proliferating cell indices in human astrocytomas

Mutations of the p53 gene are one of the most frequent genomic alterations of human tumours of astrocytic lineage. Because the physiological role of this gene is a suppression of cellular proliferation and growth, the overexpression of p53-protein may correlate with the expression of PCNA or Ki-67, established markers of cell proliferation. Paraffin-embedded surgical specimens from 60 human astrocytomas (9 pilocytic tumours, 12 WHO grade II, 9 anaplastic astrocytomas [WHO grade III] and 30 glioblastomas [WHO grade IV]) were stained with anti-PCNA (PC10), anti-p53(DO-7) and anti-Ki-67 antibodies (DAKO). Approximately 40% of all the cases were p53-protein immunopositive (53.3% glioblastomas, 33.3% anaplastic, 41.7% low grade astrocytomas but no pilocytic tumor). Statistical analysis did not reveal statistically significant correlation between p53-immunopositivity and PCNA or Ki-67 labeling indices. The Ki-67- and PCNA LI-s were statistically correlated, and the former better discriminated groups of different grades of malignancy.

Identification of the antigen recognized by the monoclonal antibody BU31 as lamins A and C

The murine monoclonal antibody BU31 binds to the nuclear membrane of many cell types. The expression of the BU31 antigen has previously been shown to have an inverse correlation with the proliferative index in lung tumours, defined by Ki67 staining. The distribution of BU31-positive cells is now shown to parallel the distribution of non-dividing cells in a range of normal human and rat tissues, although neuroendocrine cells and germ cells in the testis show no reactivity. Cells grown in culture and induced to undergo growth arrest show a higher level of labelling with BU31 than their proliferating counterparts. Confocal laser scanning microscopy reveals that the BU31 antigen is distributed predominantly along the nuclear lamina, with occasional internal foci. This distribution is very similar to that of the nuclear membrane proteins lamin A and lamin C, suggesting that the BU31 antigen and lamins A and C could be one and the same. Immunoblotting using recombinant lamin proteins confirmed this proposal. Moreover, a monoclonal antibody to the non-proliferation-associated antigen, statin, also recognizes lamins A and C. These data indicate that the demonstration of lamins A and C can be used to provide information on the proliferative activity of normal and neoplastic tissues. These data also suggest a role for nuclear lamins A and C during cellular quiescence, possibly through the reorganization and maintenance of nuclear structure, or more directly through interactions with the retinoblastoma gene product or related proteins.

The Pathology of Medullary Carcinoma of the Thyroid: Review of the Literature and Personal Experience on 62 Cases

The aim of the present review is to analyze the numerous pathological patterns of medullary carcinoma of the thyroid (MCT) and discuss the problems of differential diagnosis with other thyroid and nonthyroid tumors. In addition, morphological parameters and phenotypic features were related to the clinical outcome. The recent literature was reviewed and compared with the features of 62 MCTs observed at our institution. The most common patterns of growth are trabecular, alveolar and spindle cells, but MCT can mimic virtually all other primary thyroid tumors and some nonthyroid neoplasms. This heterogeneity has no proven implications for prognosis, but is of relevance for diagnostic purposes, as the differential diagnosis of MCT can be difficult in nonclassical cases. In agreement also with the literature data, no relationship between histopathological parameters and outcome was found in our series, although clinically aggressive tumors had a more advanced stage at presentation. Immunocytochemica demonstration of calcitonin is apparently the only valid criterion for a correct typing of MCT. Chromogranin A is an additional sensitive marker of MCT and parallels calcitonin expression in the majority of cases.

Association between the apoptotic index and established prognostic parameters in endometrial adenocarcinoma

The aim of this study was to determine if the apoptotic index can be readily determined for endometrial carcinoma in hysterectomy specimens and to establish if any association exists between the apoptotic index and tumour grade and stage. The apoptotic index, defined as the percentage of morphologically identified apoptotic cells and apoptotic bodies in 3000 tumour cells, was calculated for 15 adenocarcinomas of the endometrium. An association between apoptotic index and tumour grade and stage was sought. Two grade 3 adenocarcinomas of endometrium had a higher apoptotic index (5.15% to 6.43%) than 13 grade 1 and 2 lesions (1.18% to 3.8%) and formed a distinct group in this series. No association between apoptotic index and tumour stage was demonstrable. Apoptotic index can be readily estimated in routine hysterectomy specimens for endometrial adenocarcinoma. A high apoptotic index shows an association with features normally correlated with a poor clinical outcome although its value as an independent prognostic index has yet to be established.