Association between cyclooxygenase-2-expressing macrophages, ulceration and microvessel density in colorectal cancer.

AIM: In colorectal carcinomas, cyclooxygenase-2 (COX-2) is expressed predominantly by epithelial cells and is implicated in tumour progression. Tumour-associated macrophages may influence tumour growth, proliferative rate and angiogenesis and also express COX-2 when activated. Thus they may play an important stromal-epithelial role in carcinogenesis. Tauhe aim of this study was to define the relationship between microvessel density (MVD), tumour COX-2 and macrophage COX-2 expression. METHODS AND RESULTS: Sixty-five cases of formalin-fixed paraffin-embedded colorectal cancer were included in the study. Tissues were immunostained for COX-2, CD68 (macrophage marker) and CD34 (endothelial marker to assess MVD). Thirty-six cases were grossly ulcerated cancers and 29 cases showed focal/microscopic ulceration. Macrophages were in high concentration at the base of ulcerated areas, and were also diffusely dispersed within tumoral stroma. However, the pattern of macrophage COX-2 expression revealed two populations of macrophages--those deep within the tumour (negative for COX-2) and those at the base of ulcers (positive for COX-2). In all cases, the tumour epithelial cells expressed COX-2. MVD was higher at the base of ulcers, adjacent to COX-2+ macrophages, and was lower deep within the tumour. CONCLUSIONS: In colorectal cancers, macrophages may have a dual role. Those concentrated at the base of the ulcers, where there is an associated high MVD, may induce angiogenesis, but their function may be in a healing/repair process. The lack of COX-2+ macrophages and lower MVD deep within the tumour suggests that it may be the epithelial COX-2 component that is important in tumour progression.

Recurrent aneurysmal fibrous histiocytoma.

Aneurysmal fibrous histiocytoma is a rare variant of cutaneous fibrous histiocytoma that results from blood vessel proliferation and haemorrhage into a fibrous histiocytoma. The resulting lesion has a very different clinical appearance, hence the potential confusion with other skin lesions. This report describes the case of a 48 year old woman with a recurrent fibrous histiocytoma with prominent vasculature, which over a three year period recurred on two occasions, showing more progressive features of the aneurysmal variant. In addition, squamous lined cysts were present within this tumour, a finding that has not been described previously. The histological features of this rare lesion and the importance of the differential diagnosis from other similar appearing malignant lesions will be discussed.

CD44V6 in gastric carcinoma: a marker of tumor progression.

CD44 is a group of cell surface molecules involved in cell-cell and cell-matrix interactions. CD44 spliced variants (CD44V) have been found to enhance the metastatic potential of rat tumors. Tumors from the breast, colon, and thyroid express many alternatively spliced products; nonneoplastic tissues do not. Some authors suggest that CD44V5 and V6 may play a role in gastric carcinoma. The aim of the current study was to investigate the role of CD44V6 as a prognostic marker and predictor of metastatic potential in gastric carcinomas. One hundred fifty-five cases of gastric adenocarcinomas were studied: 36 cases of early (EGC), 19 cases of intermediate (MGC), and 100 cases of advanced gastric adenocarcinomas (AGC). A monoclonal antibody against CD44V6 (R&D) was used. CD44V6 expression was positively correlated with advanced stage (P = 0.05). Strong positivity was only detected in those cases of AGC with metastases. Patients with CD44V6 positive tumors revealed a lower 3- and 5-year survival rate (P = 0.0002). Immunohistochemical detection of CD44V6 could now be used as an indicator of tumor progression in biopsies of patients with gastric carcinoma.

Poor agreement in recognition of abnormal mitoses: requirement for standardized and robust definitions.

AIMS: The finding of abnormal mitoses is a helpful feature in differentiating between benign and malignant neoplasia and has prognostic significance for some tumours. As the use of a histopathological variable is limited by the reproducibility of its recognition, we tested the interobserver agreement in the classification of abnormal mitoses among histopathologists. METHODS adn RESULTS: Ten practising histopathologists were shown 30 potential mitotic figures and were asked to classify these as 'normal mitoses', 'abnormal mitoses' or 'not mitoses' according to the criteria each pathologist used in their routine practice. The results were analysed using kappa statistics. Overall agreement was only fair with a combined kappa of 0.31 and there was unanimous categorization of only four of 30 test items, none of which was called abnormal. The poorest result was obtained for the category 'abnormal mitosis' with only slight agreement (kappa 0.19). Agreement for the other categories varied from moderate (kappa = 0.45) for 'not a mitosis' to fair (kappa = 0.26) for 'normal mitosis'. Comparison of the results for observer pairs showed that for 12 out of the 45 possible pairings, there was no more agreement than might be expected by chance alone. CONCLUSION: Agreement is poor among practising histopathologists in the recognition of abnormal mitoses. A standardized and robust definition is needed if diagnostic and prognostic significance is accorded to the finding of an abnormal mitosis in the context of neoplasia.

Deletion of the FHIT gene in neoplastic and invasive cervical lesions is related to high-risk HPV infection but is independent of histopathological features.

The fragile histidine triad (FHIT) gene encompasses the common chromosomal fragile site FRA3B. Human papilloma virus (HPV), which is the main aetiological agent in cervical cancers, has been found to be able to integrate its genes into the chromosome 3 fragile site of cultured cells, deleting a piece of DNA which includes the FHIT gene. Eighty-six microdissected archival cervical LLETZ biopsies comprising cases of cervical intraepithelial neoplasia (CIN) 1 (n=27), CIN3 (n=30) and microinvasive carcinoma (n=29) were evaluated for HPV infection and FHIT gene loss of heterozygosity (LOH). FHIT gene LOH was detected by polymerase chain reaction (PCR) using fluorescently labelled intragenic microsatellite markers D3S1300 and D3S4103. PCR products were analysed on a semi-automated DNA sequencer using Fragment Manager(trade mark) software to determine allele loss. The HPV status of the lesions was determined by PCR using generic and type-specific primers in conjunction with restriction endonuclease digestion. The results were analysed using Epi-Info and SPSS-PC statistical analysis software. Haematoxylin and eosin-stained sections from the 86 cases were profiled for six histopathological features, some of which have been previously shown to be associated with microinvasive cancer. FHIT gene LOH was found in 36% of CIN1 cases, 52% of CIN3 cases and 73% of microinvasive cases (p=0.029). HPV 16 DNA was found in 68% of CIN3 cases and 93% of microinvasive cases (p<0.001). The second most prevalent HPV type found was HPV 31, which was present in only four lesions, three of which had FHIT gene LOH. When FHIT gene LOH was evaluated versus HPV 16 and 31 infection using the chi-square test, a statistically significant relationship was found (p=0.014). FHIT gene LOH was found to be independent of the histopathological features evaluated. The finding of a statistically significant relationship between FHIT gene LOH and oncogenic HPV infection suggests a link between the integration of viral DNA and subsequent gene deletion in the progression of cervical cancer. FHIT gene anomalies may prove to be excellent markers of progression in early uterine cervical cancers.

Immunohistochemical expression of nm23 in primary invasive malignant melanoma is predictive of survival outcome.

The objective of this study was to determine the utility of nm23 as an immunohistochemical indicator of prognosis in a large series (157 cases) of malignant melanoma and also in two subsets within this group: stage 1 tumours, whether in radial or vertical growth phase (140 cases); and stage 1 tumours in which a vertical growth phase component was positively identified (123 cases). A secondary objective was to explore the relationship between the immunohistochemical expression of nm23 and established clinical and histological indicators of prognosis in each of these three groups. In all groups it was found that strong immunoreactivity correlated positively with survival and inversely with indicators of poor prognosis, in keeping with transfection and mRNA studies and also with many immunohistochemical studies of other tumour types. That these findings are at variance with earlier reported immunohistochemical studies of melanoma highlights the importance of large case numbers of primary invasive tumours in studies which set out to explore the relationship between immunoreactivity and survival.

Catecholamine secretion and ploidy in phaeochromocytoma.

The aim was to evaluate 24 hr urine catecholamine, HMMA and HVA excretion in relation to ploidy in phaeochromocytoma. Data from five diploid and nine tetraploid tumours showed a significant reduction in urine noradrenaline (p = 0.02) and HMMA (p = 0.03) in diploid tumours but no difference in adrenaline, dopamine and HVA excretion using the Mann-Whitney U test. None of the patients showed recurrence after a mean of 5.7 years of follow up. A review of published ploidy studies in phaeochromocytoma shows that malignancy is more than six times more common in non-diploid tumours but diploidy does not equate with benignity. No biochemical marker is a reliable index of malignancy. All patients should undergo lifetime review for recurrence.

Identification of vertical growth phase in malignant melanoma. A study of interobserver agreement.

Ninety-four H & E-stained slides of malignant melanoma were circulated to 6 pathologists in 2 university departments. For each slide, the growth phase of the lesion, Breslow thickness, and Clark level were determined by each observer. The aims of the study were to evaluate agreement between nonspecialist pathologists in identifying the vertical growth phase in malignant melanoma and to compare agreement for the growth phase with agreement for Breslow thickness and the Clark level. Our results show that although overall agreement for the growth phase is moderate, agreement between experienced observers is good. In fact agreement for the growth phase among this group was equal to the agreement for Breslow thickness. Overall agreement for Breslow thickness also was good but for the Clark level was only fair. These findings suggest that if the predictive value of the vertical growth phase proves to be robust, it will be used with an acceptable level of accuracy in routine diagnostic practice.

Altered expression of the p53-regulated proteins, p21Waf1/Cip1, MDM2, and Bax in ultraviolet-irradiated human skin.

The distribution of p21WAf1/CiP1, MDM2, and Bax/Bcl-2 proteins in ultraviolet (UV)-irradiated and nonirradiated human skin was examined immunohistochemically and compared with p53 protein levels. Sun-protected buttock skin from three volunteers was exposed to solar simulated irradiation, and biopsies were performed 0.5, 1, 2, 4, and 24 hours after irradiation as well as control unirradiated skin from the opposite buttock. A similar staining pattern was observed in each of the three volunteers. P53 protein was detectable in all skin samples examined. P21Waf1/CiP1 protein was visible in the nuclei of cells at 4 hours, and staining intensity increased at 24 hours. MDM2 protein expression was noted in isolated nuclei in the epidermis at 24 hours. Bax cytoplasmic staining was evident in the basal layer of the epidermis of all samples, and this staining appeared to increase in intensity in the 4- and 24-hour specimens. There was no Bcl-2 immunohistochemical staining in any sample. These results suggest that p53 and genes/proteins under the control of p53 are altered/ activated in normal human skin in response to UV exposure.

Mild abnormalities in liver histology associated with chronic hepatitis: distinction from normal liver histology.

BACKGROUND: Chronic hepatitis C virus infection associated with contaminated anti-D immunoglobulin has become an issue of recent concern. The clinical course of chronic hepatitis C infection is unpredictable and histological assessment is felt to be the most reliable means of assessing disease status. Semiquantitative scoring systems have been devised, which assess degree of necroinflammatory disease activity (grade) and extent of disease progression with fibrosis (stage) in chronic hepatitis. Often, using these systems, biopsies of anti-D associated chronic hepatitis C cases show mild changes only, with low scores. The significance of these low scores is uncertain. AIMS: To evaluate the significance of low scores in chronic hepatitis. METHODS: Liver biopsies were assessed from two groups of patients in whom liver histology would be expected to be normal: 30 cases of Gilbert's syndrome and 13 necropsy cases of young people (< 45 years) with no history or risk factors for liver disease. These biopsies were scored using the histological activity index of Knodell et al and its recent modification (separation of scores for grade and stage) by Ishak et al. RESULTS: Twenty of 30 cases of Gilbert's syndrome and 11 of the 13 necropsy cases had chronic hepatitis scores of 1 or 2, whereas only eight cases of Gilbert's and two necropsy cases had scores of 0. The remaining two Gilbert's cases had scores of 3 and 5. Similar results were found using both the histological activity index of Knodell et al and the method of Ishak et al. CONCLUSION: The finding of low but positive scores using these systems in people with normal liver histology questions the reliability and significance of finding such scores in patients with chronic hepatitis and is of particular concern in the evaluation of chronic hepatitis C infection.

Evaluation of p53 protein expression in renal cell carcinoma: comparison of two antibodies.

The aims of this study were to establish a profile for the expression of p53 in primary renal cell carcinoma using the polyclonal antibody NCL-CB1 and the monoclonal antibody D07, and to compare the results of staining with both antibodies. Ninety-six cases were studied using formalin-fixed paraffin-embedded tissue. Positive nuclear staining ranged from 5% (D07) to 12% (NCL-CM1). Positive cytoplasmic staining ranged from 7% (D07) to 25% (NCL-CM1) of cases. Interobserver agreement was excellent. The findings suggest that such a low level of immunohistochemical positivity reduces any potential prognostic value for p53 in this tumour type.

Inter-observer variation of p53 immunohistochemistry--an assessment of a practical problem and comparison with other studies.

The aims of this study were to analyse the expression of p53 by immunohistochemistry in a range of malignant and pre-malignant conditions and to assess the degree of inter-observer variability in interpretation of p53 immunostaining. Formalin-fixed paraffin-embedded sections from 28 colorectal carcinomas (CRC), 40 cervical intraepithelial neoplasia lesions (CIN), 22 transitional cell carcinomas of the bladder (TCC), 10 invasive squamous carcinomas of uterine cervix and 21 squamous cell carcinomas of skin were examined. A polyclonal antibody was used in 90 cases. A monoclonal antibody was used in the remainder. Ten cases were stained with both. Aberrant expression of p53 protein was documented in 48% of squamous cell carcinomas of skin, 29% of CRC, 22% of CIN and 23% of TCC. All cases of squamous cell carcinoma of uterine cervix were negative. Inter-observer variation occurred in 7% of cases examined. This was confined to two tumour groups, TCC and CIN. Our results showed that p53 oncoprotein expression by immunohistochemistry was identified in 26% of cases but the range was wide (0-48%) and appeared to be tumour specific. Inter-observer variability in the interpretation of immunohistochemical staining was low (7%) and was restricted to two tumour groups.

The pathology of cervical cancer.

The significant changes over the last decade in the CIN/cervical carcinoma area have involved the increasing recognition of many cervical carcinomas as adenocarcinomas, rather than squamous cell type, and their propensity for arising in young women. Another area of interest is the deployment of new molecular techniques that are unveiling the role of oncogene co-factors (e.g. HPV, p53) in the biologic evolution of CIN and hopefully glandular dysplasia.

Infantile fibromatosis with involvement of the mandible.

Two unusual cases of infantile fibromatosis involving the mandible occurring in 2-year-old children are described. These tumours, though initially highly aggressive, underwent spontaneous regression in the absence of definitive treatment.