Includes bibliographical references (leaves 40-44). / The aims of this study were to determine the age at presentation and the racial distribution of prostatic adenocarcinoma in the Western Cape region and correlate this with histological grade; to correlate the expression of androgen receptor, bcl-2, p53 and Cox-2 with the Gleason grade of disease and patient demographic data and to establish a method to determine androgen receptor (AR) gene amplification in formalin fixed prostatic carcinoma tissue.

Includes abstract. Includes bibliographical references.

Introduction: Anal cancer is a rare disease which accounts for 1.5% of gastrointestinal tract malignancies. The majority of these carcinomas are squamous cell carcinomas and are associated with high risk-HPV infection. HIV infection appears to interact synergistically with high risk-HPV in the development of squamous cell carcinoma at this site. Aims and objectives: To review the pathology of anal carcinomas and anal intraepithelial neoplasia (AIN) diagnosed between 2003 and 2012. To investigate the frequency of high risk-HPV infection and HIV infection in premalignant and malignant epithelial anal lesions using immunohistochemistry and to investigate the effect of these infections on Langerhans cell density. To investigate the role of cell cycle and WNT signalling pathway markers in the pathogenesis of these lesions. Materials and methods: This was a retrospective study and 51 cases of anal carcinoma and precursor lesions were identified during the study period. Where possible, blocks which contained normal and dysplastic tissue and invasive carcinoma were selected. Ten immunohistochemical stains (p24, p16, pRb, E-cadherin, CD1a, Langerin, Bcl-2, Ki-67, HPV L1 capsid protein and β-catenin) were performed and scored in normal, dysplastic and carcinomatous tissue. Data were analysed to determine if there were statistically significant differences in the expression of markers in different subtypes of carcinomas, grades of differentiation of carcinomas and in the range from normal to carcinoma. Results: The patients' ages ranged from 24 to 81 years. There were 26 females and 24 males; one patient did not have age or sex information available. Twenty-one cases did not have information available on HIV status. Eleven cases demonstrated squamous cell dysplasia only and 40 cases demonstrated invasive carcinoma, 36 of these being squamous cell carcinomas. p24 was positive in only two known HIVpositive cases. p16 demonstrated block positive staining in 35 out of 36 squamous cell carcinomas and 14 out of 18 high grade squamous intraepithelial lesions. There was a significant decrease in the proportion of pRb-positive cells from well to poorly differentiated squamous cell carcinomas (p=0.03). HIV status did not influence the expression of markers. The subtype of carcinoma did not have a significant effect on the proportion of pRb-positive cells. Differentiation of squamous cell carcinoma had a significant effect on the E-cadherin expression score (the more well differentiated a carcinoma, the higher the E-cadherin score; p=0.04). There was a significant difference in E-cadherin expression between normal tissue and squamous cell carcinoma, and dysplastic tissue and squamous cell carcinoma (p=0.002 and p=0.004, respectively). Differentiation, subtype of squamous cell carcinoma and HIV status did not influence the density of CD1a/Langerin-positive Langerhans cells. No significant difference in the density of CD1a/Langerin-positive cells was demonstrated amongst normal, dysplastic and squamous cell carcinoma tissue, regardless of HIV status. The differentiation, subtype of squamous cell carcinoma and HIV status, did not have a significant effect on the Bcl-2 expression. There was a significant difference in Bcl-2 expression among normal, dysplastic and cancerous tissue (p=0.02). There was no significant difference in the Ki-67 proliferation index amongst the different subtypes of squamous cell carcinoma and the degrees of differentiation. HPV L1 capsid IHC only stained two squamous cell carcinomas and nine cases with dysplastic squamous epithelium (AIN I and AIN II). There was no case which showed abnormal localisation of β-catenin. Conclusion: Less than 20% of HIV-positive cases showed positive p24 staining. p24 does not appear to be a useful stain to determine HIV status in non-lymphoid tissues. p16 is known to be a surrogate marker for high risk-HPV infection, and the fact that 35 out of 36 squamous cell carcinomas showed block positive staining suggests that the majority of squamous cell carcinomas in this study were associated with high risk-HPV infection. The mean density of CD1a- and Langerin-positive cells was increased in HIVpositive patients. HPV L1 capsid IHC showed a low sensitivity of detecting AIN and invasive SCC of the anus. Including vaccinations against high risk-HPV in the South African Expanded Programme on Immunisation may reduce the burden of anal dysplastic lesions and invasive squamous cell carcinoma in future.

Background: Castleman disease (CD) is a lymphoproliferative disorder with four subtypes, some of which are aetiologically linked to Human Herpes virus 8 (HHV-8) which is known to cause diseases preferentially occurring in HIV-infected individuals. There has been a notable increase in the number of patients with HIV/HHV-8 associated CD diagnosed in the Groote Schuur hospital complex. Aims: The aim of the study was to determine the role of DC-SIGN, DC-SIGNR, p24 and HHV-8 (LANA-1) in Castleman disease. Our objectives were to identify the presence of DC-SIGN and DC-SIGNR in HHV-8 infected cells, determine whether HHV-8 and p24 (HIV) co-infection occurs in the same cells and to determine whether HHV-8 infects B and/or T cells. This study not only represents the largest and first immunophenotypic investigative evaluation of CD but also signifies the first double staining immunohistochemical analysis of CD diagnosed at Groote Schuur hospital. Methods: This was both a retrospective descriptive as well as an analytic cross-sectional immunohistochemistry study. Fifty cases of CD diagnosed at the Division of Anatomical Pathology, National Health Laboratory Service, Groote Schuur hospital over a ten and half year period were included in the study. Double immunohistochemistry was used to characterise HHV-8 infected cells using LANA-1 antibody, in conjunction with DC-SIGN, DC-SIGNR, p24, CD20 and CD3. Immunophenotypic analysis was then performed to assess 1) the number of infected HHV-8 cells and 2) number and distribution of cells co-expressing HHV-8 and DC-SIGN, DC-SIGNR, p24, CD20 and CD3. The immunophenotypic profiles were then compared to the CD morphologic subtypes. Results: The study cohort included 26 male and 24 female patients (M: F = 1.08:1), mean age 37.7 years. There were 16 hyaline vascular CD (HV-CD), 16 plasmablastic CD (Pb-CD). Nine plasma cell CD and 9 mixed-CD subtypes. There was a statistically significant association between HIV (n=45) and HHV-8 (n=40) positivity (p < 0.0002). CD4 counts and HAART enrolment were not predictive of CD development (p = 0.6120). Concurrent Kaposi sarcoma was seen in 16% (n=8) of the cohort. When comparing Pb-CD and HV-CD, there were statistically significant differences in density of LANA-1 infected cells (p<0.0002), LANA-1/DC-SIGN co-expressing cells (p <0.0072) and LANA-1/p24 co-expressing cells (p<0.0001). Conclusions: The findings of this study suggest that DC-SIGN may have a role in HHV-8 entry into cells. Furthermore, there is evidence that HIV and HHV-8 co-infection may function synergistically in CD. It is possible that DC-SIGN and DC-SIGNR facilitate dual viral entry into cells and influence viral replication and persistent infection.

Introduction: It has been reported that HNPCC colorectal carcinomas demonstrate a better prognosis compared to sporadic carcinoma, however the exact mechanism for this is still uncertain. It is possible that tumour morphology, location and cell cycle markers may be indicators of the underlying molecular mechanism. In a resource limited setting these factors may help to stratify which cases need further molecular testing and genetic counselling. Aims and objectives: To characterise the macroscopic and microscopic pathology in three cohorts of patients. The cohorts include (1) patients with CRCs that are < 50 years and mutation negative, (2) < 50 years and DNA mismatch repair gene mutation positive and (3) more than 50 years (sporadic). To investigate the immunoexpression of the cell cycle regulators (p21, p27, p53, c-myc, cyclin D1 and cyclin E) and MMP-7 in each cohort. To compare the immunoexpression of each marker between cohort s. To correlate the immunoexpression of each marker with tumour type, stage and grade. Materials and methods: In total, 17 mutation negative, 15 mutation positive and 28 sporadic adenocarcinoma resection cases were available for study. The histopathological features of all cases were reviewed. The cases were stained with antibodies against p21, p27, cyclin D1, cyclin E, p53, c- myc MMP -7, MLH1, MSH2 and MSH6. Results were considered statistically significant if P < 0.05, and P <0.017 if 3 pairs of medians were compared. Results: The mutation positive tumours were more frequently right sided tumours and showed mucinous differentiation, tumour infiltrating lymphocytes and an expanding border. The sporadic and mutation negative cohort s showed similar morphology. In the sporadic cohort, the five tumours that were MLH1 negative demonstrated morphological features of MSI-H tumours. MLH1 mutations were the commonest. MLH1 immuno expression was lost in the mutation positive tumours and was statistically significant when compared to the other two cohorts. There was no statistical significance among the three cohorts for MSH2 and MSH6 immunoexpression. There was no statistically significant difference in immunoexpression for p21, p27, p53 and MMP-7 among the three cohorts. Furthermore, there was no association with tumour type and stage. Cyclin D1 expression was increased in the mutation positive cohort and was statistically significant when compared to the mutation negative cohort only. Cyclin E expression was also increased in the mutation positive cohort and was statistically significant when compared to the sporadic cohort only. Conclusion: The morphological features of colorectal carcinomas can be helpful in identifying MS I-H tumours and cases requiring further molecular studies. The cell cycle marker expression s did not explain the expected differences in patient outcome and prognosis. The mutation negative cohort in our population continues to remain enigmatic and further testing at the molecular level is required, that may reveal another novel pathway of colorectal carcinogenesis or other novel mutations in mismatch repair genes.

Includes bibliographical references (leaves 67-72). / Liver dysfunction is common, often unrecognised and likely to increase in incidence in the population in parallel with the obesity and attendant type 2 diabetes mellitus epidemics. Liver fibrosis is a significant finding in liver pathology as it imparts important clinical staging and prognostic information, is a risk marker of adverse clinical outcome yet, even if advanced, is capable of reversal. Histological examination of liver biopsy material is the reference standard in the assessment of liver fibrosis, but it is impractical to biopsy all patients suspected of having liver disease. Serumprolidase is among novel biomarkers that have been described in diagnosing and/or staging liver fibrosis. This study evaluated the measurement and the diagnostic accuracy of serumprolidase in determining the potential presence and degree of liver fibrosis compared with liver biopsy.

Includes bibliographical references (leaves 52-65). / Gastric remnant carcinoma (GRC) is a gastric cancer that develops in gastric remnant more than five years after resection for benign disease. GRC comprises 1 %-9% of all gastric cancers. Partial gastrectomy for peptic ulcer is thought to be a risk factor for GRC. Pancreato-duodenal and bile reflux may play an important part in the aetiology of GRC. Primary gastric carcinoma (pGC) is a gastric cancer that arises in un-operated stomach and chronic gastritis is a well-known risk factor. Consequently there appear to be differences in the aetiology of GRC and PGC. According to many studies, surgical treatment of early GRC (Stage I or II) resulted in the same or better prognosis with similar stage PGC. However if diagnosed late, GRC has a worse prognosis than PGC at the same stage. In this study haematoxylin and eosin, alcian blue pH 2.5, periodic acid Schiff, high iron diamine and Giemsa stains as well as immunohistochemical methods (eight antibodies against MUCI to MUC6) were used to determine the type of mucin and the pattern of staining in twenty cases of GRC and twenty PGC (ten cases of intestinal type PGC, ten diffuse type PGC) and ten normal gastric mucosal biopsies. The aim of the study was to describe the morphology of GRC and the adjacent gastric mucosa, as well as to determine the histochemical and immunohistochemical mucin profile of GRC and to compare this with that of PGC and normal mucosa.

Includes abstract. / Includes bibliographical references (leaves 80-93). / The study aimed to contribute a South African perspective by correlating the HIV status and prognosis of DLBCL and PBL with differentiation profiles assessed by immunophenotyping.

Background Weighing of organs is a necessary part of every autopsy and provides objective evidence of pathology, especially in forensic cases where histology is not always taken. Reference ranges must be locally applicable, accurate, and regularly defined. Aims The primary aim was generation of post-mortem organ weight reference ranges for use in South African mortuaries. Secondary aims were analysing factors influencing organ weights, and comparison of data to those from international populations. Methods A retrospective study was conducted using autopsy reports from the Salt River medico-legal mortuary in Cape Town, South Africa between 2013 and 2016. Disproportionate randomized stratified sampling was used to obtain sufficient cases from males and females; White, Coloured, and African racial groups; and decedents both older and younger than 50 years. Observations from 1262 decedents >18 years old dying traumatic on-scene deaths were recorded, excluding organs with macroscopic evidence of disease or destructive injury. The organs considered were the brain, heart, both lungs, liver, spleen, and both kidneys, and the variables collected were sex, race, age, height and body weight. This study was approved by the University of Cape Town Human Research Ethics Committee. Results Sampled decedents are described and excluded organs accounted for. Descriptive statistics are presented for each of the stratified subsamples. After assumption testing, multiple linear regression models are built, including interaction terms. Factors influencing organ weights are discussed and results compared to selected studies. Ideal organ weight reference ranges are proposed, based on 95% inclusion data from decedents aged 18-35 years with normal body mass indices. A smartphone application is offered, which calculates prediction intervals for individual decedents based on the multiple linear regression models. Conclusion This is the first study on post-mortem organ weights in South Africa, and despite limitations it provides useful locally derived population estimates.

Includes bibliographical references (leaves 163-176). / The term "Nonalcoholic steatohepatitis" (NASH) describes a form of liver disease indistinguishable from alcoholic liver disease, but present in persons who consume insignificant amounts of alcohol. The spectrum of non-alcoholic liver disease ranges from non-progressive steatosis, through to NASH and sometimes to cirrhosis. Risk factors predisposing to NASH include obesity, diabetes mellitus, hypertriglyceridermia and procedures leading to rapid and profound weight loss such as gastric bypass and bulimia. Given the high incidence of type II diabetes, obesity and various types of hyperlipidaemia in the Western Cape, NASH has become one of the most commonly encountered liver diseases in the Liver Clinic, Groote Schuur Hospital. Statistics also suggest nonalcoholic fatty liver disease underlies most cases of elevated liver enzymes in many other parts of the world. The exact pathogenic mechanisms involved are not well understood, and no effective treatment options are currently available. However, animal models of NASH now provide unique opportunities for study of this disease in the laboratory setting. This thesis employs a dietary animal model, which restricts methionine and choline intake, to replicate aspects of the injurious process in human NASH. Two lines of inquiry are pursued. The first involves an assessment of the effect of alcohol consumption on fatty liver of non- alcoholic aetiology. Elevated liver enzymes, altered levels of lipid peroxides, and increased cytochrome P450 activity recorded in this study, suggest alcohol may exacerbate nonalcoholic fatty liver disease. The second line of inquiry is an exploration of the role of Tumor Necrosis Factor alpha (TNFα, a cytokine implicated in pathogenesis of alcoholic liver disease and thought to be pivotal in NASH pathogenesis. The role of TNFα in the dietary model of NASH is investigated using mice lacking functional TNFα genes, as well as wild type mice in which expression of this cytokine is induced by endotoxin challenge. Endotoxin challenge does elicit a marked inflammatory response and enhanced generation of lipid peroxides in the fatty liver, both of which may contribute to injury. However, as knockout mice still develop experimental NASH, TNFα cannot be considered the sole driving force required for the development of NASH. This strength of the project lies in the use of a variety of techniques (in the fields of Pathology, Immunology and Lipid Biochemistry) to investigate a range of aspects of NASH. The results of the alcohol study may provide the first empirical evidence supporting the need to restrict alcohol intake in patients with NASH, while the data on TNFα is vital for illuminating the complex, (potentially) counter-intuitive role of this cytokine in NASH. Where definitive conclusions cannot be drawn from the data, the questions posited may constitute the basis for future research.