Diffuse Large B-Cell Lymphoma in Kenya: MYC, BCL2, and the Cell of Origin

Purpose: Diffuse large B-cell lymphoma (DLBCL) is the most commonly diagnosed non-Hodgkin lymphoma in adults in Kenya. Cell of origin (COO) and double expression of MYC and BCL2 are two important prognostic factors for DLBCL. A small subset (5% to 10%) of DLBCL cases show positivity for CD5 and are associated with poor prognosis, whereas CD30 antigen, seen in up to 10% of cases, may be a useful target for therapy. We sought to determine the prevalence of MYC/BCL2 double expression, COO, and proportion of Epstein-Barr virus positivity among patients with DLBCL diagnosed at a tertiary referral laboratory in Kenya. Patients and Methods: All cases of DLBCL diagnosed from 2012 through 2015 in our pathology department were analyzed. Tumor tissue microarray sections were stained with CD20, CD3, CD5, CD30, BCL2, BCL6, CD10, MUM1, MYC, and Ki67, classified for COO on the basis of the Hans algorithm, and subjected to Epstein-Barr virus-encoded small RNAs in situ hybridization. Results: Among 165 DLBCL cases, the median age was 50 years, and there was no sex predilection. Only 18 (10.9%) cases showed double expression for MYC and BCL2. Germinal center B (GCB)-cell type DLBCL accounted for 67 cases (40.6%) and 97 cases (59.4%) were classified as non-GCB. The mean Ki67 proliferation index was significantly higher in the double-expressing (45%) and non-GCB groups (36%) compared with the non-double-expressing group (29%) and GCB group (26%). Sixteen cases (9.7%) were Epstein-Barr virus-encoded small RNAs positive, 12 (75%) of which were non-GCB. Conclusion: DLBCL in Kenya is seen in much younger patients with the poor prognostic non-GCB-type accounting for 59.4% of cases. MYC and BCL2 double expression was seen in fewer tumors than reported in the literature and in significantly older patients

P16 expression and recurrent cervical intraepithelial neoplasia after cryotherapy among women living with HIV

Background: The expression of p16 protein, a surrogate marker for high-risk human papillomavirus (hrHPV), is associated with cervical dysplasia. We evaluated correlates of p16 expression at treatment for high-grade cervical lesions and its utility in predicting the recurrence of cervical intraepithelial lesions grade 2 or higher (CIN2+) following cryotherapy among women with HIV. Methods: This is a subgroup analysis of women with HIV in Kenya with baseline cervical biopsy-confirmed CIN2+ who were randomized to receive cryotherapy and followed every six-months for two-years for biopsy-confirmed recurrence of CIN2+. P16 immunohistochemistry was performed on the baseline cervical biopsy with a positive result defined as strong abnormal nuclear expression in a continuous block segment of cells (at least 10–20 cells). Results: Among the 200 women with CIN2+ randomized to cryotherapy, 160 (80%) had a baseline cervical biopsy specimen available, of whom 94 (59%) were p16-positive. p16 expression at baseline was associated with presence of any one of 14 hrHPV genotypes [Odds Ratio (OR)  =  3.2; 95% Confidence Interval (CI), 1.03–9.78], multiple lifetime sexual partners (OR  =  1.6; 95% CI, 1.03–2.54) and detectable plasma HIV viral load (\u3e1,000 copies/mL; OR  =  1.43; 95% CI, 1.01– 2.03). Longer antiretroviral therapy duration (≥2  years) at baseline had lower odds of p16 expression (OR  =  0.46; 95% CI, 0.24–0.87) than \u3c2  years of antiretroviral therapy. Fifty-one women had CIN2+ recurrence over 2-years, of whom 33 (65%) were p16-positive at baseline. p16 was not associated with CIN2+ recurrence (Hazard Ratio  =  1.35; 95% CI, 0.76–2.40). Conclusion: In this population of women with HIV and CIN2+, 41% of lesions were p16 negative and baseline p16 expression did not predict recurrence of cervical neoplasia during two-year follow up

Prevalence of Double MYC/BCL2 Expression and the Cell of Origin in Diffuse Large B-Cell Lymphomas Diagnosed at a Tertiary Level Referral Laboratory

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most commonly diagnosed non-Hodgkin’s lymphoma in adults worldwide. In Kenya DLBCL accounts for 64% of all non-Hodgkin’s lymphomas diagnosed in adults. It is a heterogeneous disease and patients show varying outcomes despite standard treatment. This variability is attributed to the differences in the biology and molecular pathogenesis of DLBCL. The five most important prognostic factors for DLBCL include scores for the revised international prognostic index (R-IPI), the cell of origin (COO), presence of myelocytomatosis (MYC) and B-cell lymphoma 2 (BCL2) gene rearrangements by fluorescent in situ hybridisation (FISH) or standard cytogenetics, the absolute lymphocyte and monocyte count, and imaging with positron emission tomography (PET scan). Current data shows that the use of immunohistochemistry in identifying cases of DLBCL with MYC and BCL2 protein over-expression (double-expressing lymphomas) yields important prognostic information since these patients form a higher proportion of cases compared to those with concurrent MYC and BCL2 translocations (double-hit lymphomas) using FISH/cytogenetics . The double expressing DLBCL have a poorer prognosis compared to cases of DLBCL lacking MYC/BCL2 double-expression. With advances in targeted therapy for DLBCL, it is important to also identify patients who may benefit from new regimens by determining their cell of origin. Gene expression profiling (GEP), the technique for determining the COO is not available to the routine diagnostic laboratory. Consequently, robust immunohistochemistry surrogates have been developed in place of GEP for this purpose. Hans’ algorithm which uses three antibodies in sequence (CD10, BCL6 and MUM1) is the most widely applied for determining COO. The World Health Organization (WHO) guidelines currently recommend definition of the cell of origin and testing for double MYC/BCL2 expression for every patient diagnosed with diffuse large B cell lymphoma. Furthermore, in order to establish a diagnosis of DLBCL, NOS with certainty, other high-grade B-cell lymphomas, such as Burkitt lymphoma and plasmablastic lymphoma, need to be excluded. This can be achieved by a comprehensive antibody panel that includes MYC and BCL2. These antibodies need to be optimised and standardised for the settings in which a particular laboratory operates. Objectives: To determine the prevalence of MYC/BCL2 double-expression among diffuse large B cell lymphomas diagnosed at The Aga Khan University Hospital, Nairobi (AKUH, N) Laboratory. To define the cell of origin of DLBCL diagnosed at AKUH, N laboratory. Methods: Formalin fixed Paraffin embedded (FFPE) blocks of DLBCL cases diagnosed between January 1st 2012 and December 31st 2015 were retrieved from the archives at the pathology Department of AKUHN. Hematoxylin /Eosin sections were reviewed for adequacy and Tissue Microarrays (TMA) constructed and stained with CD3, CD5, CD10, CD20, CD30, MUM1, BCL6, BCL2, MYC and Ki67 for determination of COO and BCL2/MYC double expression Additional cyclin D1 immuno-staining was performed on all CD5 positive cases to exclude pleomorphic mantle cell lymphoma. Data Analysis: Data analysis utilized SPSS® version 23 (IBM corporation, Armonk, New York, USA). Descriptive statistics for median age, sex preponderance, tumour site (whether nodal or extranodal) were analysed. The prevalence of cases expressing both MYC and BCL2 was calculated as a proportion of the total number of cases included in the study. The cell of origin for each case was determined as either germinal center origin (GCB) or non-germinal center (non-GCB) with their respective proportions calculated from the total number of cases included in the study. The proportion of CD5 and CD30 positive cases was also determined. Fisher’s exact test was performed on 2 by 2 tables for correlation between double expression and sex, cell of origin and site with a p value of \u3c0.05 considered significant. A student t-test was used to compare mean ages and Ki67 indices between double expressing and non-double expressing groups as well as GCB and non-GCB groups. Results: A total of 165 cases of DLBCL were included in the study for which two TMA blocks were constructed and stained for cell of origin and double expression. The median age for the study group was 50 years. There was an even distribution by gender with males accounting for 54.5% of cases. Majority of the cases were from nodal sites (57.9%). The mean Ki67 index was 30% (Range: 0 to 100%). Only 18 cases were found to be positive for both MYC and BCL2 accounting for 10.9% of all DLBCLs. The double expressing tumors showed a higher mean Ki67 index of 45% compared to the non-double expressing group (29%). No difference was noted in median age, sex preponderance, cell of origin or site of occurrence between the two groups. A total of 67 cases accounting for 40.6% of the cases were classified as GCB. Of the 97 non-GCB cases, 64 (70%) occurred in extranodal sites, a statistically significant correlation (p=0.016). The non-GCB group also showed mean higher Ki67 index (36%) compared to GCB group (26%) (p=0.008). No differences were detected in sex or median ages between these two groups. A total of 121 cases were analysed for CD5 immunoreactivity with 11(9.1%) cases showing positivity. All but one of the positive cases occurred in males. No differences were detected in median ages, mean Ki67 indices, cell of origin or site of occurrence between the CD5 positive and negative groups. None of the CD5 positive cases expressed cyclin D1. Only 3 (2.5%) cases out of the 122 stained expressed CD30. Conclusion: We report a lower prevalence of MYC/BCL2 double expression as compared to studies conducted in the West. This understates the reasons for this as an area for future studies. However, we report a higher prevalence of the poor prognosis non-GCB subtype of DLBCL understating the need for routine analysis of COO for all DLBCL cases to include rituximab as an adjuvant to CHOP. Classification for cell of origin at diagnosis is also crucial to prognosticate and predict outcomes in our patients. Prevalence of CD5 positive cases is similar to reported literature. The effect of higher prevalence of HIV in our region was not studied due to lack of clinical information and certainly warrants further exploration in future prospective studies. The value of routine CD30 staining remains to be confirmed given the low prevalence of this sub-group in the study

Fibroadenoma With Pleomorphic Stromal Giant Cells: It\u27s Not as Bad as It Looks!

Clinically relevant histological categorization of fibroepithelial lesions can be a daunting task, especially in a core needle biopsy. Assessment of stromal nuclear atypia, including nuclear pleomorphism and mitotic activity, is a key morphological feature employed to classify fibroepithelial lesions. We describe a case of fibroadenoma with markedly atypical nuclear features in the stromal cells that led to misclassification as phyllodes tumor in the core needle biopsy. Excision showed a fibroadenoma containing pleomorphic stromal giant cells, with occasional mitotic figures, including atypical forms. Aforementioned nuclear findings in a fibroepithelial lesion raise a legitimate question of phyllodes tumor. Knowledge of this pitfall may help avoid overtreatment of an otherwise benign fibroepithelial lesion

Clear Cell Lesions of the Mullerian System: Not Always That Clear !

A spectrum of lesions, benign and malignant, of the Mullerian system display clear cells. Interpretation of this finding can be confusing resulting in significant interobserver variability even among gynecologic pathologists.1 It is critical to distinguish bona fide clear cell carcinoma from other endometrial lesions as management is significantly different. We present some key morphologic aspects of endometrial clear cell carcinoma and compare it with 2 other endometrial lesions with clear cells: endometrial surface epithelial changes, clear cell type (SECs),2 and Arias- Stella reaction, posing a major diagnostic pitfall, especially when present in small biopsy material

Large Epithelial and Stromal Lesion of Breast: It’s Not Always Phyllodes!

Fibroepithelial lesions (FELs) of breast often pose a diagnostic challenge to pathologists.1 In this article, we share gross and microscopic findings of 3 large breast lesions with epithelial and spindle cell components: (1) a giant fibroadenoma (FA; Figure 1 [1A-C]), (2) a borderline phyllodes tumor (World Health Organization classification2; Figure 1 [2A-C]), and (3) a nodular pseudoangiomatous stromal hyperplasia (NPASH; Figure 1 [3A-C]). This brief report highlights histological overlap between NPASH and FELs, and describes morphological clues that can help pathologists in differentiating NPASH from FELs with PASH-like stroma

Verrucous Carcinoma Arising in Association With Giant Condyloma

Verrucous carcinoma (VC) is a histologic subtype of squamous cell carcinoma characterized by highly differentiated squamous cells with a bulbous invasive pattern of the underlying stroma.1-3 It is a rare entity, often associated and confused with giant condyloma of Buschke-Löwenstein. Some authors consider the 2 entities to be distinct.1,3,4 They should be distinguished from giant condylomas by virtue of their low rate of positivity for high-risk human papilloma virus infection and lack of koilocytic atypia.1,2,4,5 On the other hand, these lesions should be distinguished from conventional squamous cell carcinomas because they pose virtually no risk for nodal metastases.1,3 However, there are published reports showing that VC and conventional squamous cell carcinoma can coexist in the same lesion. Conventional squamous cell carcinoma can also arise form VC.6 These reports suggest that VC is but one of the morphologic transitions of conventional squamous cell carcinoma.

Breast camps for awareness and early diagnosis of breast cancer in countries with limited resources: A multidisciplinary model from Kenya

Background. Breast cancer is the most common cancer of women in Kenya. There are no national breast cancer early diagnosis programs in Kenya. Objective. The objective was to conduct a pilot breast cancer awareness and diagnosis program at three different types of facilities in Kenya. Methods. This program was conducted at a not-for-profit private hospital, a faith-based public hospital, and a government public referral hospital. Women aged 15 years and older were invited. Demographic, risk factor, knowledge, attitudes, and screening practice data were collected. Breast health information was delivered, and clinical breast examinations (CBEs) were performed. When appropriate, ultrasound imaging, fine-needle aspirate (FNA) diagnoses, core biopsies, and onward referrals were provided. Results. A total of 1,094 women were enrolled in the three breast camps. Of those, 56% knew the symptoms and signs of breast cancer, 44% knew how breast cancer was diagnosed, 37% performed regular breast self-exams, and 7% had a mammogram or breast ultrasound in the past year. Of the 1,094 women enrolled, 246 (23%) had previously noticed a lump in their breast. A total of 157 participants (14%) had abnormal CBEs, of whom 111 had ultrasound exams, 65 had FNAs, and 18 had core biopsies. A total of 14 invasive breast cancers and 1 malignant phyllodes tumor were diagnosed Conclusion. Conducting a multidisciplinary breast camp awareness and early diagnosis program is feasible in different types of health facilities within a low- and middle-income country setting. This can be a model for breast cancer awareness and point-of-care diagnosis in countries with limited resources like Kenya. The Oncologist 2016;21:1138–114

Geographic Variability of Nodular Lymphocyte-Predominant Hodgkin Lymphoma: A Clinicopathologic Reappraisal in the Modern Era

Objectives: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) differs from classic Hodgkin lymphoma (CHL) in terms of clinicopathologic features, including Epstein-Barr virus (EBV) association. CHL geographic variability is well known, with higher frequencies of mixed-cellularity subtype and EBV positivity in low/middle-income countries (LMICs), but there are few well-characterized series of NLPHL from LMICs. Methods: We detail clinicopathologic findings of 21 NLPHL cases received in consultation from Kenya and summarize reports of NLPHL with EBV testing published since 2000. Results:  Median age of consultation cases was 36 years, and male/female ratio was 3.2. All cases involved peripheral lymph nodes and showed at least some B-cell–rich nodular immunoarchitecture, with prominent extranodular lymphocyte-predominant (LP) cells and T-cell–rich variant patterns most commonly seen. LP cells expressed pan–B-cell markers, including strong OCT2; lacked CD30 and CD15 expression in most cases; and were in a background of expanded/disrupted follicular dendritic cell meshworks and increased T-follicular helper cells. LP cells were EBV negative in 18 cases. Historical cases showed a low rate of EBV positivity with no significant difference between LMICs and high-income countries. Conclusions: Unlike CHL, NLPHL shows few geographic differences in terms of clinicopathologic features and EBV association. These findings have implications for diagnosis, prognostication, and treatment of patients with NLPHL in LMICs