Colorectal cancer in Tanzania: the current status and future directions.

Introduction: Globally, colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer death. By 2030, the incidence is expected to increase to reach 2.2 million cases and 1.1 million deaths. In Sub-Saharan Africa, accurate cancer incidence data is limited, but anecdotally, clinicians note a significant rise in the incidence of CRC in the past decade. To educate clinicians on the growing burden of CRC, the Tanzanian Surgical Association hosted a 4-day CRC symposium from 3rd to 6th October 2022. Following the meeting, a group of multidisciplinary stakeholders created a working group whose first task was to assess the epidemiology, presentation and available resources for CRC care in Tanzania. The findings of that assessment are described in this article. Findings: The true incidence of CRC in Tanzania is currently unknown. However, individual high-volume centres have noted a dramatic rise in cases of colon and rectal cancer on their wards. A review of the published data on CRC in Tanzania showed that most patients present with CRC late and the limited availability of endoscopic and diagnostic services poses a challenge for accurately staging these patients prior to treatment. Multidisciplinary care, including surgery, chemotherapy and radiation, is available for the treatment of CRC in Tanzania, although the capacity and quality of these services vary throughout the country. Conclusion: There is a substantial burden of CRC in Tanzania that appears to be increasing. While there is capacity in the country to provide all aspects of multidisciplinary care, late presentation, limited access to diagnostic and treatment services and poor coordination continue to be significant barriers to providing optimal treatment to these patients.

Gestational trophoblastic disease and associated factors among women experiencing first trimester pregnancy loss at a regional referral hospital in central Tanzania: a cross-sectional study.

BACKGROUND: Gestational trophoblastic diseases (GTDs) may follow any form of pregnancy or a pregnancy loss. Early detection of GTDs is important, as some benign forms of the disease may progress into a chemoresistant and metastatic disease. This study aimed at determining the frequency of GTDs among women experiencing first trimester pregnancy loss and the associated patients' characteristics. METHODS: This was a cross-sectional study that included 200 conveniently sampled women who experienced first trimester pregnancy loss from January to December 2019 at a Regional Referral Hospital in central Tanzania. The specimen obtained from products of conception were collected, formalin-fixed and paraffin-embedded and submitted for histopathological evaluation, for which haematoxylin and eosin stain was used. Data were analysed using SPSS version 23.0. The χ2 test was used to determine the association between categorical variables. p-Values ˂0.05 were considered statistically significant. RESULTS: Among 200 study participants, the overall frequency of GTDs was 42 (21%). Among those with GTDs, the most common histopathological diagnosis was partial hydatidiform mole (18 [42.9%]), followed by complete hydatidiform mole (17 [40.5%]) and choriocarcinoma (7 [16.5%]). In the studied participants, only increased human chorionic gonadotropin hormone levels were found to be statistically significantly associated with GTDs (p=0.000). CONCLUSIONS: Results from this study suggest that routine histopathological evaluation of the products of conception is recommended in order to allow early detection of GTDs, including choriocarcinoma, which usually carries a poor prognosis. The histopathological reporting of choriocarcinoma among first trimester products of conception from Tanzania is novel.

Histopathological evaluation of chronic rheumatic mitral valve stenosis: the association with clinical presentation, pathogenesis, and management at a National Cardiac Institute, Tanzania.

AIMS: The histopathology of mitral valve (MV) tissues have been reported in necropsy and retrospective studies. We prospectively studied the histopathological changes in rheumatic mitral stenosis using advanced techniques and corroborated these with clinical presentation, pathogenesis, and management. METHODS: From January 2020 to February 2021, surgically excised rheumatic stenotic MV from 54 Tanzanian patients were studied. These were examined using hematoxylin-eosin, von Kossa staining, and immunohistochemistry. RESULTS: The median (range) age of patients was 39 (14-57) years with 34 (63%) females. Secondary prophylaxis was given to 7 (13%) patients and 2 (3.7%) had evidence of rheumatic fever (RF). With hematoxylin-eosin, 37 (68.5%) specimens showed fibrinoid degeneration (FD), 44 (81.5%) leucocytic infiltrates, 6 (11.1%) Aschoff nodules, 30 (55.6%) calcification, and 39 (72.2%) fibrosis. Thirty-five (64.8%) specimens were positive to von Kossa. The proportion of specimens positive for CD3, CD20, CD68, and CD8 were 46 (85.2%), 35 (64.8%), 39 (72.2%), and 8 (14.8%) respectively. Valvular calcium was high among older patients, males and with a higher trans-MV gradient. The degree of inflammatory cellular infiltration was associated with valvular calcification, FD with ARF, leucocytic infiltrates with disease duration of <10 years, and fibrosis with the absence of atrial fibrillation. C-reactive protein and anti-streptolysin titres were high in CD20 and CD8 staining cells. CONCLUSION: This study confirms that high MV calcium are found in patients who are old, male, and with severe mitral stenosis. The association between clinical parameters with histopathological-immunohistochemical studies observed in our study provides new insight to disease presentation. We found a low rate of secondary prophylaxis and two patients with ARF. Our findings are comparable with those from other countries suggesting similar pathogenesis and thus intervention modalities. This is the first study on mitral valve histopathology to be reported from Africa.

Histologic detection of Helicobacter pylori by the immunohistochemical method using anti-Helicobacter pylori polyclonal antibody: A cross-sectional study of patients with gastric pathologies at the Muhimbili National Hospital in Dar-es-salaam, Tanzania.

BACKGROUND AND STUDY AIM: Immunohistochemistry is one of the superior methods and is regarded as the gold standard for the detection of Helicobacter pylori. We aimed to detect the presence of Helicobacter pylori in gastric biopsies among patients at the Muhimbili National Hospital from January 2012 to December 2016. Also, we determined the predictors of Helicobacter pylori infection. PATIENTS AND METHODS: Retrospectively, we retrieved the tissue blocks of gastric biopsies at the Central Pathology Laboratory of the patients with different gastric pathologies at the Muhimbili National Hospital from January 2012 to December 2016. Helicobacter pylori were detected using anti-Helicobacter pylori polyclonal antibodies. Binary logistic regression analysis was done to determine the predictors of Helicobacter pylori infection. A two-tailed p < 0.05 was considered significant. RESULTS: The prevalence of detection of Helicobacter pylori was 37.1% (63/170) using immunohistochemistry compared to 32.4% (55/170) using histology. Peptic ulcer disease, the absence of gastric cancer, and chronic gastritis were the predictors of Helicobacter pylori infection in our study (AOR = 0.2, 95% CI = 0.06-0.70, p = 0.011, AOR = 3.23, 95% CI = 1.02-10.29, p = 0.047, AOR = 0.32, 95% CI = 0.12-0.87, p = 0.025, respectively). CONCLUSION: In this study, Helicobacter pylori infection was associated with the presence of peptic ulcer disease, chronic gastritis, and the absence of gastric cancer. The rate of detection of Helicobacter pylori infection was higher in tissue blocks of elderly patients than in those of young patients. Also, gastric cancer was more prevalent in old female patients.

Epstein-Barr Virus Latent Membrane Protein-1 Expression in Nasopharyngeal Carcinoma.

PURPOSE: Nasopharyngeal carcinoma (NPC), a malignant neoplasm of the epithelium covering the nasopharynx, is a rare disease in most parts of the world. Epstein-Barr virus (EBV), the most potent oncogenic virus, coupled with environmental and genetic factors has been identified to play a role in the development of NPC. An array of methods for detecting the virus do exist, from serologic detection of antibodies to DNA amplification. There is paucity of local data on the status of EBV infection in relation to NPC within the region, and this study attempts to shed more light on the subject. METHODS: This was a retrospective cross-sectional laboratory-based study on histologically confirmed, archived tissues from July 2015 to June 2019. Immunohistochemistry expression of latent membrane protein-1 (LMP-1) was used to detect EBV infection in the tissues. RESULTS: A total of 71 cases were enrolled in this study. The mean age was 47.87 years ± 16.84 years with a male-to-female ratio of 1.5:1. There was a unimodal distribution of EBV detection, with the peak (26.8%) at 36-45 years. About 45.1% of the 71 samples tested positive for LMP-1, all of which were nonkeratinizing carcinoma. Nonkeratinizing carcinoma was the most common histopathologic subtype (n = 67; 94.4%), with the majority (38 of 67; 56.7%) being undifferentiated and 29 of 67 (43.3%) differentiated. Keratinizing and basaloid subtypes had two cases each, representing 2.8%. CONCLUSION: A significant proportion of NPC, particularly nonkeratinizing histologic subtype, seems to show LMP-1 positivity by immunohistochemistry, which may be adopted in resource-constrained settings to detect EBV infection in these tissue biopsies.

Expression of Progesterone Receptor and Its Association with Clinicopathological Characteristics in Meningiomas: A Cross-Sectional Study.

BACKGROUND: Meningiomas that are progesterone receptor positive have a low recurrence rate and good prognosis compared to those that are progesterone receptor negative. This study aimed to determine the prevalence of expression of progesterone in meningiomas and its association with clinicopathological characteristics. MATERIALS AND METHODS: This was a cross-sectional laboratory-based study that was conducted at Muhimbili National Hospital. The study included 112 formalin-fixed paraffin-embedded tissue blocks of patients who were confirmed to have meningiomas on histological basis from January 2010 to December 2014. Immunohistochemical expression of progesterone receptor was tested using a primary monoclonal progesterone receptor antibody ready to use (IR 068 Dako). The χ2 test was used to determine the association between clinicopathological characteristics and progesterone receptor expression. A 2-tailed P < 0.05 was considered significant. RESULTS: The mean age of the patients was 45.5 ± 3.601 years, and majority (66.1%, n = 74) were in the age group between 31 and 60 years. Also, majority of the patients (60%, n = 67) in this study were females. Over one-third of the cases (34.8%, n = 39) comprised of meningotheliomatous subtype, and majority of the cases (89.3%, n = 100) were of grade I. The prevalence of progesterone expression was 54.5% (n = 61), and only age was associated with progesterone receptor expression (P = 0.043). CONCLUSION: The finding of high expression of the progesterone receptor for grade I cases in this study indicates that progesterone receptor expression in meningiomas is of prognostic value and may be considered when evaluating patients for management. Lack of expression of progesterone receptor in all the malignant cases is intriguing and needs further studies that can investigate its prognostic role.

Evaluating Estrogen Receptor Immunohistochemistry on Cell Blocks From Breast Cancer Patients in a Low-Resource Setting.

CONTEXT.­: Breast cancer biomarker assessment is critical in determining treatment and prognosis. In Tanzania, immunohistochemistry (IHC) is limited to surgical specimens and core biopsies. However, performing IHC on fine-needle aspiration biopsy cell blocks would offer numerous advantages. OBJECTIVE.­: To compare the performance between estrogen receptor (ER) IHC performed at Muhimbili National Hospital (MNH) in Tanzania and ER IHC performed at University of California, San Francisco (UCSF), to demonstrate feasibility of performing IHC using cell blocks in Tanzania. DESIGN.­: Patients with breast masses were recruited prospectively from the fine-needle aspiration biopsy clinic at MNH. Estrogen receptor IHC results on cell blocks, performed at both MNH and UCSF, and corresponding tissue blocks, performed at MNH, were compared to determine concordance. RESULTS.­: Eighty-six cell blocks were evaluated by ER IHC at MNH, with 41 of 86 (47.7%) positive and 45 of 86 (52.3%) negative. Among 65 UCSF and MNH cell block pairs, overall ER IHC concordance was 93.8% (61 of 65) and positive concordance was 93.5% (29 of 31) (κ = 0.88, P > .99). Among 43 paired UCSF cell blocks and MNH tissue blocks, overall ER IHC concordance was 88.3% (38 of 43) and positive concordance was 90.5% (19 of 21) (κ = 0.77, P > .99). We compared 62 MNH cell block and tissue block pairs. Overall ER IHC concordance was 90.3% and positive concordance was 87.9% (κ = 0.81, P = .69). CONCLUSIONS.­: Pairwise comparisons between ER IHC at MNH, on cell blocks and tissue blocks, with ER IHC at UCSF on cell blocks showed excellent concordance. We demonstrate that ER IHC on fine-needle aspiration biopsy specimens can be implemented in resource-constrained settings.

The Role of a Minimum Immunohistochemical Antibody Panel in Confirming Undifferentiated Nasopharyngeal Carcinoma: A Cross-Sectional Study at the Muhimbili National Hospital, Dar-es-Salaam, Tanzania.

INTRODUCTION: Nasopharyngeal carcinoma (NPC) is a malignant epithelial neoplasm arising in the nasopharyngeal mucosa that shows light microscopic and/or ultrastructural evidence of squamous differentiation. Immunohistochemistry (IHC) can be used to reliably distinguish undifferentiated NPC from other malignant tumors, and the technique may be a necessary tool toward the arrival of a definitive diagnosis, particularly when dealing with challenging cases. MATERIALS AND METHODS: This was a cross-sectional hospital-based study which was conducted at Muhimbili National Hospital. The study involved 120 patients with NPC who were diagnosed on histopathological basis between 2009 and 2013. RESULTS: The sensitivity and specificity of hematoxylin and eosin (H and E) stain in diagnosing NPC were 99% and 30.4%, respectively. The accuracy of H and E stain to diagnose NPC and lymphoma was 94.2% and 30.4%, respectively. CD45 antibody helped to confirm 16 cases which were diagnosed as NPC on H and E stain to be lymphoma. Further, AE1/AE3 antibody helped to confirm one case who was diagnosed as rhabdomyosarcoma on H and E stain to be NPC. CONCLUSIONS: The sensitivity and accuracy of H and E stains to diagnose NPC were very high whereas the specificity was very low. A significant proportion of previously diagnosed NPC cases by routine H and E stains were confirmed not to be so by a minimal IHC antibody panel of pan-cytokeratin cocktail (AE1/AE3) and leukocyte common antigen (CD45). This highlights the paramount importance of a minimum IHC panel in assisting to obtain a definitive diagnosis in challenging cases of NPC.

Characterization of hormonal receptors and human epidermal growth factor receptor-2 in tissues of women with breast cancer at Muhimbili National Hospital, Dar es salaam, Tanzania.

BACKGROUND: Breast cancer is a leading cause of morbidity and deaths among women worldwide. In Tanzania there is no published data on human epidermal growth receptor-2 (HER2/neu) expression in breast carcinoma. Hormonal receptors and HER2/neu status reportedly influence post-mastectomy adjuvant therapy and predict treatment outcome and prognosis. Here we evaluate hormonal receptors and HER-2 status in biopsies of women with breast cancer at Muhimbili National Hospital (MNH). METHODS: A cross-sectional study of female breast post-modified radical mastectomy (MRM)/incisional biopsies confirmed to be carcinoma at the Histopathology Unit (January-December 2013). Tissue blocks having poor morphology, without tumor, secondary tumors, cases outside the study period and male patients were excluded. Routine staining was done followed by immunohistochemistry for estrogen (ER), and progesterone (PgR) receptors and HER2. Data analyzed using Statistical Package for Social Sciences (SPSS). RESULTS: A total of 218 cases were confirmed to be carcinoma including 70 meeting inclusion criteria. Age at diagnosis ranged 18-75 years and mean age was 48.36 years. Majority (64.3%) were in the 36-55 years age-group. Histologically, most (88.6%) women had invasive ductal carcinoma including 43.1% of intermediate grade. A great majority (78%) were stage three. Due to logistical constrains, 75.7% (n = 53/70) cases where immunostained for hormones including 43.4% (ER+), 26.4% (PgR+), and 28% (ER+/PgR+). Furthermore, 65.7% (n = 46/70) cases were immunostained for HER-2 and 15.2% (n = 7/46) were positive, 45.6% were triple negative (ER-,PgR-,HER2-), 23.9% (ER+,PgR+,HER2-) or luminal B, 2.2% (ER+,PgR-,HER2+),13% (ER-,PgR-,HER2+) and 15% (ER+,PgR-,HER2-) with none being triple positive. CONCLUSIONS: Hormonal receptors and HER2 expression at MNH appears to be comparable to previous Africans/African Americans reports but not with studies among Caucasians and the current proportion of triple negative breast carcinomas (TNBC) is higher than in a previous Tanzanian report and majority are luminal. HER2 over-expression is relatively common. It is strongly recommended that receptor status assessment be made routine for breast cancer patients at MNH.

The Doctor of Medicine curriculum review at the School of Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania: a tracer study report from 2009.

BACKGROUND: The School of Medicine (SoM) is one among five at Muhimbili University of Health and Allied Sciences (MUHAS). It currently houses eight undergraduate and many post-graduate programmes. The Doctor of Medicine (MD) programme reported herein is the oldest having ten semesters (5 years) followed by a 1 year compulsory rotatory internship at a hospital approved by the Medical Council of Tanganyika (MCT). However, this training was largely knowledge-based and thus the need to shift towards competency-based education (CBE) and full modularization necessitated this study. METHODS: A cross-sectional tracer study of MUHAS MD graduates from SoM who completed training between 2006 and 2008 was conducted using quantitative (structured interviewer-administered questionnaires) as well as qualitative methods [In-depth questionnaire (IDI) and Focus group discussions (FGDs)]. RESULTS: A total of 147 MD graduates were traced and interviewed, representing 29 % of the 510 students who graduated from the SoM between 2006 and 2008. Majority (70.1 %, n = 103/147) were males. About 70 % graduated in 2008 and majority (68 %, n = 100/147) were doing internship. Majority (60.5 % n = 89/147) were based in/near Dar es Salaam at district, regional or referral hospitals. With reasonable concordance, most competencies ranked low except on four aspects. Teaching, System-based Practice and Good Practice had the lowest. Seminars/Tutorials, Laboratory Skills/Practicals, Theatre Skills, Outpatients clinics, Family Case Studies, Visits/Excursions and Self Reflection were rated less useful teaching methods compared to Lectures, Teaching Ward Rounds, Elective Studies, Field Work, Presentations, Continuous Assessments Tests, Final Examinations, Short Answers, Clinical/Practical Examinations. ICT and Library facilities were not considered to meet the students learning needs and Clinical Logbooks also ranked low. Teachers were generally ranked less favorably including in professional role-modelling and accessibility outside scheduled teaching sessions. CONCLUSIONS: This tracer study results allowed subsequent curriculum review and the introduction of full modularization and competency-based learning at MUHAS. It is envisioned that these tracer study findings will improve teaching, learning and inform next curriculum review at MUHAS leading to increased output of appropriately trained health professionals to fill the big gap in human resources for health (HRH) in Tanzania. The revised curricula are also being processed through TCU for accreditation as required.

The pattern of prognostic and risk indicators among women with breast cancer undergoing modified radical mastectomy in Dar es Salaam, Tanzania.

BACKGROUND: Breast cancer is the commonest female malignancy globally and the second (after uterine cervix) in sub-Saharan Africa including Tanzania. Prognostic indicators reportedly influence post-mastectomy adjuvant therapy by predicting risks on survival and recurrence although in Tanzania this data is lacking. Here, we evaluate the pattern of prognostic and risk indicators among women with breast cancer undergoing modified-radical-mastectomy (MRM) at Muhimbili National Hospital (MNH) and Tumaini Hospital (TH), Dar es Salaam, Tanzania. METHODS: This hospital-based prospective cross-sectional study included female patients undergoing MRM from April 2011 to January 2012. Clinical stage I-III patients were enrolled after being scheduled for mastectomy. Patients with evidence of distant metastasis (stage IV) were excluded. Mastectomy and axillary lymph nodes biopsies were submitted to the Histopathology laboratory for grade, type, nodal and margins status. Data was collected using a structured questionnaire and analyzed using SPSS. RESULTS: A total of 348 patients were admitted with breast cancer including 86 patients (with 16 from TH having similar demography and presentation) meeting inclusion criteria. Age-range at diagnosis was 28-79 years, mean 52.1 years. Most (89 %) attained menarche after 11 years. About 56 % were postmenopausal. The majority (78 %) were multiparous with positive family history in 14.1 and 37.6 % used hormonal contraceptives. About 27.1 % were social alcohol drinkers. The majority (61 %) had T4b disease, 75.6 % had positive axillary nodes including 42.7 % with 4-9 involved nodes (N2). The commonest (91.9 %) histological type was invasive ductal carcinoma. Lobular, medullary and mucinous carcinomas were rare. Most (83.7 %) of our patients presented with stage III and the rest stage II. Intermediate- and high-grade tumors accounted for 73.5 %. Following MRM, 25 % of our patients had positive surgical margins and similarly for the base. CONCLUSIONS: Most of our breast cancer patients present with frequent risks including younger age, multiparity, hormonal contraceptives use, alcohol use and family history. Unfavourable prognostic indicators including late stages, large primary tumor size, skin infiltration, positive surgical margins, positive axillary lymph nodes and a high histological grade were associated. A sustainable screening program by self-examination to allow early diagnosis is needed to reduce morbidity and mortality from this cancer.

Curricular transformation of health professions education in Tanzania: the process at Muhimbili University of Health and Allied Sciences (2008-2011).

Tanzania requires more health professionals equipped to tackle its serious health challenges. When it became an independent university in 2007, Muhimbili University of Health and Allied Sciences (MUHAS) decided to transform its educational offerings to ensure its students practice competently and contribute to improving population health. In 2008, in collaboration with the University of California San Francisco (UCSF), all MUHAS's schools (dentistry, medicine, nursing, pharmacy, and public health and social sciences) and institutes (traditional medicine and allied health sciences) began a university-wide process to revise curricula. Adopting university-wide committee structures, procedures, and a common schedule, MUHAS faculty set out to: (i) identify specific competencies for students to achieve by graduation (in eight domains, six that are inter-professional, hence consistent across schools); (ii) engage stakeholders to understand adequacies and inadequacies of current curricula; and (iii) restructure and revise curricula introducing competencies. The Tanzania Commission for Universities accredited the curricula in September 2011, and faculty started implementation with first-year students in October 2011. We learned that curricular revision of this magnitude requires: a compelling directive for change, designated leadership, resource mobilization inclusion of all stakeholders, clear guiding principles, an iterative plan linking flexible timetables to phases for curriculum development, engagement in skills training for the cultivation of future leaders, and extensive communication.

Cervical cytological changes in HIV-infected patients attending care and treatment clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania.

BACKGROUND: Tanzania is among Sub-Saharan countries mostly affected by the HIV and AIDS pandemic, females being more vulnerable than males. HIV infected women appear to have a higher rate of persistent infection by high risk types of human papillomavirus (HPV) strongly associated with high-grade squamous intraepithelial lesions (HSIL) and invasive cervical carcinoma. Furthermore, although HIV infection and cervical cancer are major public health problems, the frequency and HIV/HPV association of cervical cancer and HSIL is not well documented in Tanzania, thus limiting the development of preventive and therapeutic strategies. METHODS: A prospective unmatched, case-control study of HIV-seropositive, ≥ 18 years of age and consenting non-pregnant patients attending the care and treatment center (CTC) at Muhimbili National Hoospital (MNH) as cases was done between 2005 and 2006. HIV seronegative, non-pregnant and consenting women recruited from the Cervical Cancer Screening unit (CCSU) at ORCI were used as controls while those who did not consent to study participation and/or individuals under < 18 years were excluded. Pap smears were collected for routine cytodiagnosis and P53 immunohistochemistry (IHC). Cervical lesions were classified according to the Modified Bethesda System. RESULTS: A total of 170 participants from the two centers were recruited including 50 HIV-seronegative controls were from the CCSU. Ages ranged from 20-66 years (mean 40.5 years) for cases and 20-69 years (mean 41.6 years) for controls. The age group 36-45 years was the most affected by HIV (39.2%, n = 47). Cervicitis, squamous intraepithelial lesions (SIL) and carcinoma constituted 28.3% (n = 34), 38.3% (n = 46) and 5.8% (n = 7) respectively among cases, and 28% (n = 14), 34% (n = 17) and 2% (n = 1) for controls, although this was not statistically significant (P-value = 0.61). IHC showed that p53 was not detectable in HPV + Pap smears and cell blocks indicating possible degradation. CONCLUSIONS: The frequency of SIL and carcinoma appeared to be higher among HIV-infected women on HAART compared to seronegative controls and as expected increased with age. HIV seropositive patients appeared to present earlier with SIL compared to those HIV seronegative suggesting a role of HIV in altering the natural history of HPV infection and cervical lesions. The absence of p53 immunoreactivity in HPV + lesions is indicative of the ability of HPV E6 proteins to interact with the tumor suppressor gene and pave way for viral-induced oncogenesis in the studied Tanzanian women.

Diagnosis of Burkitt lymphoma using an algorithmic approach--applicable in both resource-poor and resource-rich countries.

Distinguishing Burkitt lymphoma (BL) from B cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma (DLBCL) and BL (DLBCL/BL), and DLBCL is challenging. We propose an immunohistochemistry and fluorescent in situ hybridization (FISH) based scoring system that is employed in three phases - Phase 1 (morphology with CD10 and BCL2 immunostains), Phase 2 (CD38, CD44 and Ki-67 immunostains) and Phase 3 (FISH on paraffin sections for MYC, BCL2, BCL6 and immunoglobulin family genes). The system was evaluated on 252 aggressive B-cell lymphomas from Europe and from sub-Saharan Africa. Using the algorithm, we determined a specific diagnosis of BL or not-BL in 82%, 92% and 95% cases at Phases 1, 2 and 3, respectively. In 3·4% cases, the algorithm was not completely applicable due to technical reasons. Overall, this approach led to a specific diagnosis of BL in 122 cases and to a specific diagnosis of either DLBCL or DLBCL/BL in 94% of cases that were not diagnosed as BL. We also evaluated the scoring system on 27 cases of BL confirmed on gene expression/microRNA expression profiling. Phase 1 of our scoring system led to a diagnosis of BL in 100% of these cases.

Tanzanian malignant lymphomas: WHO classification, presentation, ploidy, proliferation and HIV/EBV association.

BACKGROUND: In Tanzania, the International Working Formulation [WF] rather than the WHO Classification is still being used in diagnosing malignant lymphomas (ML) and the biological characterization including the HIV/EBV association is sketchy, thus restraining comparison, prognostication and application of established therapeutic protocols. METHODS: Archival, diagnostic ML biopsies (N = 336), available sera (N = 35) screened by ELISA for HIV antibodies and corresponding clinical/histological reports at Muhimbili National Hospital (MNH) in Tanzania between 1996 and 2006 were retrieved and evaluated. A fraction (N = 174) were analyzed by histopathology and immunohistochemistry (IHC). Selected biopsies were characterized by flow-cytometry (FC) for DNA ploidy (N = 60) and some by in-situ hybridization (ISH) for EBV-encoded RNA (EBER, N = 37). RESULTS: A third (38.8%, 109/281) of the ML patients with available clinical information had extranodal disease presentation. A total of 158 out of 174 biopsies selected for immunophenotyping were confirmed to be ML which were mostly (84. 8%, 134/158) non-Hodgkin lymphoma (NHL). Most (83.6%, 112/134) of NHL were B-cell lymphomas (BCL) (CD20+), of which 50.9%, (57/112) were diffuse large B-cell (DLBCL). Out of the 158 confirmed MLs, 22 (13.9%) were T-cell [CD3+] lymphomas (TCL) and 24 (15.2%) were Hodgkin lymphomas (HL) [CD30+]. Furthermore, out of the 60 FC analyzed ML cases, 27 (M:F ratio 2:1) were DLBCL, a slight majority (55.6%, 15/27) with activated B-cell like (ABC) and 45% (12/27) with germinal center B-cell like (GCB) immunophenotype. Overall, 40% (24/60) ML were aneuploid mostly (63.0%, 17/27) the DLBCL and TCL (54.5%, 6/11). DNA index (DI) of FC-analyzed ML ranged from 1.103-2.407 (median = 1.51) and most (75.0%) aneuploid cases showed high (>40%) cell proliferation by Ki-67 reactivity. The majority (51.4%, 19/37) of EBER ISH analyzed lymphoma biopsies were positive. Of the serologically tested MLs, 40.0% (14/35) were HIV positive, mostly with high (> or =40.0%) Ki-67 reactivity. CONCLUSIONS: According to the 2001 WHO Classification, most subtypes are represented in Tanzanian ML. Extranodal presentation was common among MNH lymphoma patients who also showed high aneuploidy, tumor proliferation (KI-67) and EBER positivity. DLBCL was frequent and phenotype heterogeneity appeared similar to observations in Western countries suggesting applicability of established intervention approaches. HIV was apparently associated with high ML cell proliferation but extended studies are needed to clarify this.

Human herpesvirus-8 (HHV-8) sero-detection and HIV association in Kaposi's sarcoma (KS), non-KS tumors and non-neoplastic conditions.

BACKGROUND: The association of the human herpesvirus-8/Kaposi's sarcoma (KS)-associated herpesvirus (HHV-8/KSHV) serology with various malignancies in Tanzania is not currently well established while previous studies were based on either PCR or immunofluorescence assays [IFA] but not with a sensitive enzyme-linked immunosorbent assay (ELISA). Selected archival diagnostic biopsies (n = 184) and sera from indigenous patients with KS (n = 120), non-KS tumors (n = 24) and non-neoplastic lesions (n = 40) at Muhimbili National Hospital (MNH), Tanzania, were evaluated by diagnostic histopathology, immunohistology [anti-HHV-8 latency-associated nuclear antigen (LANA)] and serology for HIV (ELISA) and HHV-8 (IFA and ELISA). RESULTS: About 66.3% (n = 122) cases including AIDS-associated Kaposi's sarcoma (AKS) (n = 93), reactive conditions (n = 28) and only one non-KS tumour were HIV positive. Endemic KS (EKS) patients were mostly males (96.3%, 26/27) who were less (69.9%, 65/93) predominant in AIDS-associated (AKS). A high (89%) percentage of patients with anti-HHV-8 antibodies was found in the cohort including the HIV positive (92%) cases, males (81.2%), KS patients (93%), non-KS tumors (92%), and reactive conditions (75%). All HHV-8 seronegative KS cases were nodular stage whereas both sera and corresponding biopsies from early stage KS were HHV-8+. Assay sensitivity, positive predictive value (PPV) and specificity were 98.6%, 93.5% and 16.7% for IFA and 93.5%, 98.6% and 50.0% for ELISA respectively. CONCLUSION: HHV-8 seroprevalence at MNH appears high as expected among AKS cases and males but also in non-KS patients. ELISA showed a combination of high HHV-8 sensitivity as well as higher PPV and specificity than IFA which however, showed higher sensitivity. The apparent stage-dependent, inverted serum HHV-8 immunoreactivity supports a notion of viral immune-segregation during KS development. Routine HHV-8 screening should be considered particularly in patients at risk of KS and for selection of blood/organ donations.

Malignant lymphomas (ML) and HIV infection in Tanzania.

BACKGROUND: HIV infection is reported to be associated with some malignant lymphomas (ML) so called AIDS-related lymphomas (ARL), with an aggressive behavior and poor prognosis. The ML frequency, pathogenicity, clinical patterns and possible association with AIDS in Tanzania, are not well documented impeding the development of preventive and therapeutic strategies. METHODS: Sections of 176 archival formalin-fixed paraffin-embedded biopsies of ML patients at Muhimbili National Hospital (MNH)/Muhimbili University of Health and Allied Sciences (MUHAS), Tanzania from 1996-2001 were stained for hematoxylin and eosin and selected (70) cases for expression of pan-leucocytic (CD45), B-cell (CD20), T-cell (CD3), Hodgkin/RS cell (CD30), histiocyte (CD68) and proliferation (Ki-67) antigen markers. Corresponding clinical records were also evaluated. Available sera from 38 ML patients were screened (ELISA) for HIV antibodies. RESULTS: The proportion of ML out of all diagnosed tumors at MNH during the 6 year period was 4.2% (176/4200) comprising 77.84% non-Hodgkin (NHL) including 19.32% Burkitt's (BL) and 22.16% Hodgkin's disease (HD). The ML tumors frequency increased from 0.42% (1997) to 0.70% (2001) and 23.7% of tested sera from these patients were HIV positive. The mean age for all ML was 30, age-range 3-91 and peak age was 1-20 years. The male:female ratio was 1.8:1. Supra-diaphragmatic presentation was commonest and histological sub-types were mostly aggressive B-cell lymphomas however, no clear cases of primary effusion lymphoma (PEL) and primary central nervous system lymphoma (PCNSL) were diagnosed. CONCLUSION: Malignant lymphomas apparently, increased significantly among diagnosed tumors at MNH between 1996 and 2001, predominantly among the young, HIV infected and AIDS patients. The frequent aggressive clinical and histological presentation as well as the dominant B-immunophenotype and the HIV serology indicate a pathogenic association with AIDS. Therefore, routine HIV screening of all malignant lymphoma patients at MNH is necessary to enable comprehensive ARL diagnosis and formulation of preventive and therapeutic protocols.

Kaposi's sarcoma herpesvirus load in biopsies of cutaneous and oral Kaposi's sarcoma lesions.

OBJECTIVES: To evaluate human herpesvirus 8/Kaposi's sarcoma associated herpesvirus (HHV-8/KSHV) viral load in diagnostic, (formalin fixed, paraffinised) biopsies and patient serum during tumour progression of oral and cutaneous AIDS-related Kaposi's sarcoma (AKS), and endemic Kaposi's sarcoma (EKS) by a sensitive and specific quantitative real time polymerase chain reaction (qRT-PCR) assay. STUDY DESIGN: Eighty six biopsies of both AKS (oral and cutaneous AKS, 68) and EKS (cutaneous EKS, 18) were evaluated by qRT-PCR and immunohistochemistry (IHC). The viral load in human tumour tissue and serum of some individual patients were compared. RESULTS: Higher viral load as well as frequency of latency-associated nuclear antigen (LANA)+ tumour spindle cells (SC) and number of LANA granules per SC was found in oral AKS compared to cutaneous AKS. Although few cases were available, serum viral load appeared to decrease compared to tumour tissue during KS progression. CONCLUSIONS: The higher viral load in oral rather than cutaneous AKS is consistent with the well recognised reservoir function of the oral mucosa. Decrease of serum HHV-8 load during KS progression may indicate decreased virus release and/or increased virus clearance.

Oral Kaposi's sarcoma in Tanzania: presentation, immunopathology and human herpesvirus-8 association.

Oral Kaposi's sarcoma (OKS) from Tanzanian patients (78) at Muhimbili National Hospital/Muhimbili University College of Health Sciences corresponding to approximately 10% of KS registered during 1990-2005, were diagnosed (ELISA) as HIV-infected (OAKS) (74/78) and endemic KS (4/78). Females were 69.2% (54/78) with median age 31 and males 30.8% (24/78) with median age 38. More males (50%) had systemic KS than females (37%) and 4-times more multicentric OKS. All tested (34) oral KS patients sera had HHV-8 antibodies. Available (31/78) blood showed very low CD4+ T-lymphocyte counts. Most OKS (61.5%) had nodular histology. Immunostaining showed adult male nodular OAKS to have a significantly higher frequency of viral LANA+, endothelial CD34+ tumour spindle-cells (SC) and more Ki-67+ (median =24.1%) proliferating cells compared to females (17.2%). Juvenile nodular OAKS had more LANA+ and Ki-67+ cells than corresponding adult cases. Significantly more LANA+ and Ki-67+ cells were found in nodular OAKS compared to cutaneous HIV/AIDS Kaposi's sarcoma (CAKS). A positive correlation (60%) was found between the proliferation index (Ki-67+ cell frequency) and LANA+/CD34+ SC. OKS in Tanzania is since 1990, mostly seen in females, associated with HIV/AIDS and advanced (nodular) histopathology. Males have more systemic tumour burden while more females develop primary OAKS. HHV-8+ cells were more frequent in nodular male than female and in juvenile than adult nodular OAKS than cAKS. Higher tumoral HHV-8 content appeared to be correlated to proliferation index.

KSHV/HHV-8 and HIV infection in Kaposi's sarcoma development.

Kaposi's sarcoma (KS) is a highly and abnormally vascularized tumor-like lesion affecting the skin, lymphnodes and viscera, which develops from early inflammatory stages of patch/plaque to late, nodular tumors composed predominant of spindle cells (SC). These SC are infected with the Kaposi's sarcoma-associated herpesvirus or human herpesvirus-8 (KSHV/HHV-8). KS is promoted during HIV infection by various angiogenic and pro-inflammatory factors including HIV-Tat. The latency associated nuclear antigen type 1 (LANA-1) protein is well expressed in SC, highly immunogenic and considered important in the generation and maintenance of HHV-8 associated malignancies. Various studies favour an endothelial origin of the KS SC, expressing "mixed" lymphatic and vascular endothelial cell markers, possibly representing hybrid phenotypes of endothelial cells (EC). A significant number of SC during KS development are apparently not HHV8 infected, which heterogeneity in viral permissiveness may indicate that non-infected SC may continuously be recruited in to the lesion from progenitor cells and locally triggered to develop permissiveness to HHV8 infection. In the present study various aspects of KS pathogenesis are discussed, focusing on the histopathological as well as cytogenetic and molecular genetic changes in KS.