Significance of Endocan Expression in Various Types of Epithelial Ovarian Tumors.

Background & Objective: Ovarian cancer is associated with the highest mortality rate among gynecologic malignancies. Despite new therapeutic strategies, ovarian cancer still has a high risk of metastasis and mortality. Endocan is a newly identified endothelial cell activation marker, which is responsible for angiogenesis, tumor invasion, and aggressive behavior of tumors. The aim of this study was to assess Endocan expression in different types of ovarian tumors and to identify its relationship with clinicopathologic characteristics of ovarian tumors. Methods: This cross-sectional study was conducted on 183 tissue samples, including benign, borderline, and malignant ovarian tumors collected from the University Kebangsaan Malaysia Medical Center archive of Pathology during 2005-2015. Mouse monoclonal anti-human Endocan/ESM-1 Clone MEP08 was used at a dilution of 1:400 for immunohistochemical (IHC) staining. All the information was collected by a checklist, and the association between clinicopathological features and high or low levels of Endocan -MVD was evaluated using Pearson chi-square, Fischer's exact, or Monte Carlo tests. Results: The prevalence of Endocan positivity was significantly higher in malignant compared to borderline and benign ovarian tumors (P<0.001). There was also a significant association between type of tumor and Endocan status in malignant ovarian tumors (P=0.02), indicating that Endocan positivity was more likely in serous malignant ovarian tumors compared to other ovarian tumor types. However, the tumor stage was not significantly associated with Endocan status (P=0.31). Conclusion: This study showed that Endocan positivity may show the highest prevalence among malignant tumors suggesting that high Endocan expression would be negatively associated with ovarian tumor behavior.

Rare but Potentially Fatal Presentations of Diffuse Large B-cell Lymphoma: Leukemic Phase or Hemophagocytic Syndrome in Bone Marrow.

Diffuse large B-cell lymphoma (DLBCL) is a type of non-Hodgkin Lymphoma commonly presenting as a solid tumor either by nodal or extra-nodal manifestations. Here we describe two atypical presentations of lymphoma, finally resulting in the diagnosis of DLBCL. Case 1: A 53-year-old man with a previous history of nasopharyngeal carcinoma presented with a two-week history of B-symptoms and hyperleukocytosis. Peripheral blood film showed 78% abnormal mononuclear cells. Immunohistochemical stain showing Ki-67 of 90%, negative c-myc, BCL2 and BCL6, and negative c-MYC with fluorescence in-situ hybridization studies on the trephine biopsy, concluded the diagnosis of CD5+ DLBCL of ABC subtype. He received intravenous cyclophosphamide and oral prednisolone for cytoreduction, followed by 6 cycles of chemo-immunotherapy. However, he succumbed due to severe sepsis after the completion of therapy. Case 2: A 56-year-old lady who was initially investigated for pyrexia of unknown origin was noted to have hemophagocytosis upon bone marrow aspirate examination. The bone marrow trephine biopsy revealed some atypical clusters of B-cells positive for CD20 which was inconclusive. PET-CT scan noted an enlarged hypermetabolic spleen without lymphadenopathy. Splenic biopsy with immunohistochemical studies revealed DLBCL of ABC subtype. The diagnosis was consistent with primary splenic DLBCL. She became unwell post splenic biopsy and was admitted to the intensive care unit where she passed away 2 weeks later from Candida and Sternotrophomonas septicemia. These cases highlight the atypical presentations of a common subtype of NHL in our center. Arriving at the definitive diagnosis can be difficult especially when patients are acutely ill, hampering the necessary invasive procedures for diagnosis. The outcomes of both cases are briefly discussed hoping to spread awareness among clinicians on the rare and acutely critical presentations of DLBCL.

HER2 testing by immunohistochemistry in breast cancer: A multicenter proficiency ring study.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) over-expression in breast cancer is associated with aggressive tumor behavior and predicts response to targeted therapy. Accurate HER2 result is paramount for optimal patient management. However, routine HER2 immunohistochemistry (IHC) testing are subjected to intra- and inter-laboratory variability. OBJECTIVE: This study aims to determine inter-laboratory variation in HER2 IHC testing through a slide-exchange program between five main reference laboratories. METHOD: A total of 20 breast carcinoma cases with different known HER2 expression and gene status were selected by the central laboratory in five testing rounds. Three unstained tissue sections from each case were sent to participating laboratories, which immunostained and interpreted the HER2 immunohistochemistry result. One of the stained slides was sent to one designated participating laboratory for evaluation. Results were analyzed by the central laboratory. RESULTS: A complete concordance was achieved in six IHC-positive and six IHC-negative cases, its gene status of which was confirmed by in-situ-hybridization (ISH) study. The discordant results were observed in six equivocal cases, one negative case and one positive case with a concordance rate of 50-88.3%. Interestingly, the negative discordant case actually displays tumor heterogeneity. Good inter-observer agreement was achieved for all participating laboratories (k = 0.713-1.0). CONCLUSION: Standardization of HER2 testing method is important to achieve optimum inter-laboratory concordance. Discordant results were seen mainly in equivocal cases. Intra-tumoral heterogeneity may impact the final HER2 IHC scoring. The continuous quality evaluation is therefore paramount to achieve reliable HER2 results.

CD3-positive plasmablastic lymphoma reported in two cases: A potential diagnostic caveat.

Plasmablastic lymphoma (PBL) is a rare aggressive subtype of mature large B cell lymphoma involving almost exclusively the extranodal regions particularly the oral cavity, frequently described in immunocompromised patients. PBL is characterized histologically by diffuse proliferation of large neoplastic cells resembling B immunoblasts or plasmablasts. The diagnosis of PBL can be difficult due to its ambiguous histopathological features mimicking most large cell lymphomas and lacking a distinctive immunophenotypic pattern. They typically lack expression of CD20 and CD79a but may express plasma cell marker, CD138. Aberrant immunoexpression of CD3, a T-cell marker in PBL in the absence of other B-cell markers is exceptionally rare, may potentially lead to incorrect interpretation. Herein, we report a case series of CD3-positive PBL of oral cavity in two individuals, which were initially misdiagnosed as high-grade T-cell lymphomas including extranodal NK/T-cell lymphoma, nasal type. Useful distinguishing clinical settings, histomorphological features, immunohistochemistry and molecular expression profiles of PBL are discussed.

Tumor-Derived Matrix Metalloproteinase-13 (MMP-13) Expression in Benign and Malignant Breast Lesions.

INTRODUCTION: Breast carcinoma is the most common malignancy and the leading cause of cancer death in women. Matrix metalloproteinase-13 (MMP-13) is a hypothetical prognostic marker in invasive breast cancer. This study aimed to determine MMP-13 expression in benign and malignant breast lesions and to evaluate the correlation between MMP-13 expression and tumor characteristics in invasive ductal carcinoma (IDC). MATERIALS AND METHOD: We evaluated cytoplasmic expression of MMP-13 based on staining index using immunohistochemistry (IHC) in epithelial cells, stromal fibroblasts of IDC (n=90) and benign epithelial breast (n=90) lesions. Correlation between IHC and tumor size, lymph node status, distance metastasis, estrogen receptor (ER), progesterone receptor (PR) and Her-2/neu was assessed. RESULTS: MMP-13 expression was 45% and 38.8% in malignant epithelial cells and peritumoral fibroblasts, respectively. Only low level of MMP-13 expression was seen in benign breast lesions (8.8% in epithelial component and 2.2% in stromal fibroblasts), while high level of MMP-13 expression was noted in malignant tumors, mainly grade II or III. Cytoplasmic MMP-13 expressions in epithelial tumor cells was correlated significantly with peritumoral fibroblasts. MMP-13 expression was directly correlated with distant metastasis and tumor stage in epithelial tumoral cells and was inversely correlated with progesterone expression in both tumoral and stromal cells. CONCLUSION: This study showed that MMP-13 was a moderator for tumor invasion and metastasis and could be an independent predictor of poor prognosis in breast cancer. The role of MMP-13 in predicting the risk of malignant transformation in benign lesions should be further investigated.

Nasal Angiomyolipoma (AML) Mimicking Juvenile Nasopharyngeal Angiofibroma.

INTRODUCTION: Angiomyolipoma (AML), a benign mesenchymal tumor that commonly arises from the kidney, may be associated with tuberous sclerosis complex and perivascular epithelioid cell tumors (PEComas). Nasal angiomyolipoma is very rare and usually occurs in elderly individuals with epistaxis and nasal obstruction. CASE REPORT: We report a rare case of nasal angiomyolipoma in a young male. To the best of our knowledge, this is the first documented case of angiomyolipoma originating from the posterior end of the inferior turbinate, clinically mimicking juvenile nasopharyngeal angiofibroma (JNA). The tumor was removed completely via coblator-assisted endoscopic sinus surgery. The patient was asymptomatic at a 2-year follow-up. CONCLUSION: Nasal AML located in the posterior nasal cavity in a male patient can mimic the presentation of JNA. A computed tomography scan of the paranasal sinuses played an important role in differentiating nasal AML from JNA. The coblator-assisted endoscopic technique is useful in controlling intraoperative hemostasis in the removal of a suspicious vascular tumor.

Diffuse large B-cell lymphoma in Southeast Asian cohort: expression patterns of B-cell receptor (BCR) repertoire and its linkage with molecular subtypes and response to R-CHOP therapy.

AIMS: Heightened B-cell receptor (BCR) activity in diffuse large B-cell lymphoma (DLBCL) is well established, and a subset of patients with relapsed DLBCL can benefit from BCR-targeted therapies. Universal outreach of such emerging therapies mandates forming a global landscape of BCR molecular signalling in DLBCL, including Southeast Asia. METHODS: 79 patients with DLBCL (nodal, 59% and extranodal, 41%) treated with rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) therapy were selected. Expression levels of BCR and linked signalling pathway molecules were inter-related with Lymph2Cx-based cell of origin (COO) types and overall survival (OS). RESULTS: Activated B-cell (ABC) type DLBCL constituted 49% (39/79) compared with germinal centre B-cell (GCB) type DLBCL (29/79; 37%) and revealed poor prognosis (p=0.013). In ABC-DLBCL, high BTK expression exerted poor response to R-CHOP, while OS in ABC-DLBCL with low BTK expression was similar to GCB-DLBCL subtype (p=0.004). High LYN expression coupled with a poor OS for ABC-DLBCL as well as GCB-DLBCL subtypes (p=0.001). Furthermore, high coexpression of BTK/LYN (BTK high/LYN high) showed poor OS (p=0.019), which linked with upregulation of several genes associated with BCR repertoire and nuclear factor-kappa B pathway (p<0.01). In multivariate analysis, high BTK and LYN expression retained prognostic significance against established clinical predictive factors such as age, International Prognostic Index and COO (p<0.05). CONCLUSIONS: Our data provide a clear association between high BCR activity in DLBCL and response to therapy in a distinct population. Molecular data provided here will pave the pathway for the provision of promising novel-targeted therapies to patients with DLBCL in Southeast Asia.

Pleural anthracosis presenting with massive effusion: a rare entity.

Pleural anthracosis is rare and, in most cases, is diagnosed incidentally or at autopsy. We report a 67-year-old man with pleural anthracosis. He was initially referred for possible tuberculous pleural effusion and had recurrent admissions for symptomatic pleural effusion, which increased with each subsequent episode. A thoracoscopic examination demonstrated diffuse hyperpigmentation in both parietal and visceral pleura. Parietal pleural biopsy indicated granuloma with foreign body giant cell. A contrast-enhanced computed tomography (CECT) thorax showed focal plaques in parietal pleura with calcifications in the ipsilateral lung. Investigations for tuberculosis, fungal, and malignancy proved to be negative. With these results, a diagnosis of pleural anthracosis was made. This case highlights the unusual presentation of pleural anthracosis with pleural effusion.

Role of co-expression of estrogen receptor beta and Ki67 in prostate adenocarcinoma.

Purpose: To evaluate the expression of estrogen receptor (ER)-beta and Ki67 in prostate cancer and study their relationship. Materials and Methods: We analyzed 101 cases of prostate adenocarcinoma diagnosed from January 2011 to June 2015 in 100 patients. Immunohistochemical staining of ER-beta and Ki67 was analyzed according to Gleason score categorized into prognostic groups of 1 to 5. Double-immunofluorescent staining of ER-beta and Ki67 was performed in a total of 20 cases to study the co-expression and the relationship between these markers within the same tumor. Results: A total of 53 of 101 cases (52.5%) were positive for ER-beta expression. There was a positive correlation whereby a high percentage of ER-beta expression was seen in the higher prognostic groups (groups 4 and 5; p=0.007). High Ki67 expression was observed in the higher prognostic group, whereas low Ki67 or negative expression was found in the lower prognostic group (p<0.001). The majority of cases evaluated with double-immunofluorescent staining (14/20) showed co-expression of ER-beta and Ki67 at the individual cell level. Conclusions: ER-beta and Ki67 are independent tumor markers in high prognostic groups. Hence, co-expression of ER-beta and Ki67 indicates a more aggressive tumor with a poorer prognosis.

Comparison of protein-based cell-of-origin classification to the Lymph2Cx RNA assay in a cohort of diffuse large B-cell lymphomas in Malaysia.

AIMS: The cell of origin (COO) based molecular characterisation into germinal centre B-cell-like (GCB) and activated B-cell-like (ABC) subtypes are central to the pathogenesis and clinical course in diffuse large B-cell lymphoma (DLBCL). Globally, clinical laboratories employ pragmatic but less than ideal immunohistochemical (IHC) assay for COO classification. Novel RNA-based platforms using routine pathology samples are emerging as new gold standard and offer unique opportunities for assay standardisation for laboratories across the world. We evaluated our IHC protocols against RNA-based technologies to determine concordance; additionally, we gauged the impact of preanalytical variation on the performance of Lymph2Cx assay. METHODS: Diagnostic biopsies (n=104) were examined for COO classification, employing automated RNA digital quantification assay (Lymph2Cx). Results were equated against IHC-based COO categorisation. Assay performance was assessed through its impact on overall survival (OS). RESULTS: 96 (92%) informative samples were labelled as GCB (38/96; 40%) and non-GCB (58/96; 60%) by IHC evaluation. Lymph2Cx catalogued 36/96 (37%) samples as GCB, 45/96 (47%) as ABC and 15/96 (16%) as unclassified. Lymph2Cx being reference, IHC protocol revealed sensitivity of 81% for ABC and 75% for GCB categorisation and positive predictive value of 81% versus 82%, respectively. Lymph2Cx-based COO classification performed superior to Hans algorithm in predicting OS (log rank test, p=0.017 vs p=0.212). CONCLUSIONS: Our report show that current IHC-based protocols for COO classification of DLBCL at UKM Malaysia are in line with previously reported results and marked variation in preanalytical factors do not critically impact Lymph2Cx assay quality.

Expression of the Class II and III Beta-Tubulin in Neoplastic and Non-Neoplastic Lymphoid Tissues

Aim: Abnormal expression patterns of beta-tubulin isotypes may provide a molecular rationale for the behaviour of lymphoma subtypes. In the present study class II and III beta-tubulin expression was assessed in non-neoplastic and neoplastic lymphoid tissues with reference to potential utility as new tumour biomarkers. Methods and results: In this cross-sectional study class II and III beta-tubulin expression was assessed in 304 neoplastic and 20 normal lymphoid tissues using qualitative and semi-quantitative immunohistochemistry. Class II beta-tubulin was found to be positive in the germinal centres, mantle zone and interfollicular regions of normal lymphoid tissues. It was also expressed in 15/15 (100%) lymphoblastic lymphomas, 229/231 (99%) mature B cell lymphomas, 22/22 (100%) T/NK-cell lymphomas and 36/36(100%) classical Hodgkin lymphomas. Class III beta-tubulin in contrast was germinal centre restricted and more selective, being found mainly in classical Hodgkin lymphomas (34/36 (94%)). It was also expressed in 58/171(34%) DLBCL, 11/12 (92%) mantle cell lymphomas and 6/6 (100%) Burkitt lymphomas. Other mature B cell, T/NK cell lymphomas and precursor lymphoblastic lymphomas were usually negative. Conclusions: Class II beta-tubulin shows ubiquitous expression in neoplastic and non-neoplastic lymphoisd tissues. In contrast, Class III beta-tubulin is germinal centre-restricted. Its consistent expression in classical Hodgkin lymphomas may point to use in the identification of Reed-Sternberg and Hodgkin cells. Its expression in a proportion of DLBCL, Burkitt and mantle cell lymphomas is of interest as this may be related to their aggressiveness.

Multiplexed automated digital quantification of fusion transcripts: comparative study with fluorescent in-situ hybridization (FISH) technique in acute leukemia patients.

BACKGROUND: The World Health Organization (WHO) classification system defines recurrent chromosomal translocations as the sole diagnostic and prognostic criteria for acute leukemia (AL). These fusion transcripts are pivotal in the pathogenesis of AL. Clinical laboratories universally employ conventional karyotype/FISH to detect these chromosomal translocations, which is complex, labour intensive and lacks multiplexing capacity. Hence, it is imperative to explore and evaluate some newer automated, cost-efficient multiplexed technologies to accommodate the expanding genetic landscape in AL. METHODS: "nCounter® Leukemia fusion gene expression assay" by NanoString was employed to detect various fusion transcripts in a large set samples (n = 94) utilizing RNA from formalin fixed paraffin embedded (FFPE) diagnostic bone marrow biopsy specimens. This series included AL patients with various recurrent translocations (n = 49), normal karyotype (n = 19), or complex karyotype (n = 21), as well as normal bone marrow samples (n = 5). Fusion gene expression data were compared with results obtained by conventional karyotype and FISH technology to determine sensitivity/specificity, as well as positive /negative predictive values. RESULTS: Junction probes for PML/RARA; RUNX1-RUNX1T1; BCR/ABL1 showed 100 % sensitivity/specificity. A high degree of correlation was noted for MLL/AF4 (85 sensitivity/100 specificity) and TCF3-PBX1 (75 % sensitivity/100 % specificity) probes. CBFB-MYH11 fusion probes showed moderate sensitivity (57 %) but high specificity (100 %). ETV6/RUNX1 displayed discordance between fusion transcript assay and FISH results as well as rare non-specific binding in AL samples with normal or complex cytogenetics. CONCLUSIONS: Our study presents preliminary data with high correlation between fusion transcript detection by a throughput automated multiplexed platform, compared to conventional karyotype/FISH technique for detection of chromosomal translocations in AL patients. Our preliminary observations, mandates further vast validation studies to explore automated molecular platforms in diagnostic pathology.

Obstructive jaundice in small cell lung carcinoma.

Small cell lung carcinoma (SCLC) commonly metastasizes to distant organs. However, metastasis to the pancreas is not a common event. Moreover, obstructive jaundice as a first clinical presentation of SCLC is extremely unusual. This case reports a 51-year-old male with SCLC, manifesting with obstructive jaundice as the initial clinical presentation. Endoscopic retrograde cholangiopancreatograghy (ERCP) and abdominal computed tomography (CT) scan showed a mass at the head of the pancreas. The patient underwent pancreatoduodenectomy (Whipple procedure). Histopathology revealed a chromogranin- A-positive poorly-differentiated neuroendocrine carcinoma of the pancreas. No imaging study of the lung was performed before surgery. A few months later, a follow-up CT revealed unilateral lung nodules with ipsilateral hilar nodes. A lung biopsy was done and histopathology reported a TTF- 1-positive, chromogranin A-positive, small cell carcinoma of the lung. On review, the pancreatic tumour was also TTF-1-positive. He was then treated with combination chemotherapy (cisplatin, etoposide). These findings highlight that presentation of a mass at the head of pancreas could be a manifestation of a metastatic tumour from elsewhere such as the lung, and thorough investigations should be performed before metastases can be ruled out.

Expression of DDR1 and DVL1 in invasive ductal and lobular breast carcinoma does not correlate with histological type, grade and hormone receptor status.

BACKGROUND: Invasive ductal (IDC) and lobular (ILC) carcinomas are the common histological types of breast carcinoma which are difficult to distinguish when poorly differentiated. Discoidin domain receptor (DDR1) and Drosophila dishevelled protein (DVL1) were recently suggested to differentiate IDC from ILC. OBJECTIVES: To assess the expression of DDR1 and DVL1 and their association with histological type, grading and hormonal status of IDC and ILC. MATERIALS AND METHODS: This cross sectional study was conducted on IDC and ILC breast tumours. Tumours were immunohistochemically stained for (DDR1) and (DVL1) as well as estrogen receptor (ER), progesterone receptor (PR) and C-erbB2 receptor. Demographic data including age and ethnicity were obtained from patient records. RESULTS: A total of 51 cases (30 IDCs and 21 ILCs) were assessed. DDR1 and DVL1 expression was not significantly associated with histological type (p=0.57 and p=0.66 respectively). There was no association between DDR1 and DVL1 expression and tumour grade (p=0.32 and p=1.00 respectively), ER (p=0.62 and 0.50 respectively), PR (p=0.38 and p=0.63 respectively) and C-erbB2 expression (p=0.19 and p=0.33 respectively) in IDC. There was no association between DDR1 and DVL1 expression and tumour grade (p=0.52 and p=0.33 respectively), ER (p=0.06 and p=0.76 respectively), PR (p=0.61 and p=0.43 respectively) and C-erbB2 expression (p=0.58 and p=0.76 respectively) in ILC. CONCLUSIONS: This study revealed that DDR1 and DVL1 are present in both IDC and ILC regardless of the tumour differentiation. More studies are needed to assess the potential of these two proteins in distinguishing IDC from ILC in breast tumours.

Can we confidently diagnose pilomatricoma with fine needle aspiration cytology?

Pilomatricomas can be confidently diagnosed cytologically due to their characteristic cytomorphological features. However, these lesions are rarely encountered by cytopathologists and thus pose a diagnostic dilemma to even experienced individuals, especially when the lesions are focally sampled. We describe two cases of histologically confirmed pilomatricoma. The first case is of a 13-year-old boy with posterior cervical 'lymphadenopathy', and the second one is of a 12-year-old girl with a lower cheek swelling. Both aspirates comprised predominantly atypical basal-like cells, with prominent nucleoli. 'Ghost cells' were readily identified by cell block in case two, but cell block in case one yielded no diagnostic material. In case two, pilomatricoma was accurately diagnosed pre-operatively. A cytological suspicion of a neoplastic process was raised in case one. Despite being diagnostically challenging, pilomatricoma can be diagnosed with careful observation of two unique cytological features of the lesions: (1) pathognomonic 'ghost cells' and (2) irregular, saw-toothed, loosely cohesive basaloid cells, with prominent nucleoli. The role of thorough sampling of the lesion, with multiple passes of various sites, cannot be overemphasized.

Differential expression of Toll-like receptor (TLR) and B cell receptor (BCR) signaling molecules in primary diffuse large B-cell lymphoma of the central nervous system.

Primary diffuse large B-cell lymphoma of the central nervous system (CNS DLBCL) is a distinct and aggressive lymphoma that is confined to CNS. Since, central nervous system is barrier-protected and immunologically silent; role of TLR/BCR signaling in pathogenesis and biology of CNS DLBCL is intriguing. Genomic mutations in key regulators of TLR/BCR signaling pathway (MYD88/CD79B/CARD11) have recently been reported in this disease. These observations raised possible implications in novel targeted therapies; however, expression pattern of molecules related to TLR/BCR pathways in this lymphoma remains unknown. We have analyzed the expression of 19 genes encoding TLR/BCR pathways and targets in CNS DLBCLs (n = 20) by Nanostring nCounter™ analysis and compared it with expression patterns in purified reactive B-lymphocytes and systemic diffuse large B cell lymphoma (DLBCL) (n = 20). Relative expression of TLR4, TLR5, TLR9, CD79B and BLNK was higher in CNS DLBCLs than in control B-lymphocytes; where as TLR7, MALT1, BCL10, CD79A and LYN was lower in CNS DLBCLs (P < 0.0001). When compared with systemic DLBCL samples, higher expression of TLR9, CD79B, CARD11, LYN and BLNK was noted in CNS DLBCL (>1.5 fold change; P < 0.01). The B cell receptor molecules like BLNK and CD79B were also associated with higher expression of MYD88 dependent TLRs (TLR4/5/9). In conclusion, we have shown over expression of TLR/BCR related genes or their targets, where genomic mutations have commonly been identified in CNS DLBCL. We have also demonstrated that TLR over expression closely relate with up regulation of genes associated with BCR pathway like CD79B/BLNK and CARD11, which play an important role in NF-kB pathway activation. Our results provide an important insight into the possibility of TLR and/or B-cell receptor signaling molecules as possible therapeutic targets in CNS DLBCL.

A case of t(14; 18)-negative follicular lymphoma with atypical immunophenotype: usefulness of immunoarchitecture of Ki67, CD79a and follicular dendritic cell meshwork in making the diagnosis.

Follicular lymphoma is characterised by the t(14;18)(q32;q21) chromosomal translocation causing BCL2 protein overexpression. A proportion of follicular lymphomas do not carry the t(14;18) translocation and lacked BCL2 protein expression. We describe a case of a BCL2 protein- and t(14;18)-negative follicular lymphoma that caused diagnostic difficulty. The usefulness of several immunomarkers including Ki67, CD79a and CD21 in aiding the diagnosis is discussed. The patient is a 51-year-old male who presented with gradually enlarging lymphadenopathy. Histopathological examination of the lymph node showed complete architectural effacement by neoplastic follicles containing expanded CD21-positive follicular dendritic cell meshwork. The neoplastic cells expressed pan-B cell markers (CD20, CD79a) and germinal centre marker (BCL6) but not BCL2 and CD10. Of interest are the staining patterns of Ki67 and CD79a. We observed that the Ki67- positive proliferating cells were evenly distributed within the neoplastic follicles without zonation. In addition, CD79a was homogeneously strong within the neoplastic follicles. These staining patterns were distinctly different from that observed in reactive lymphoid follicles. Fluorescent insitu hybridisation (FISH) analysis however showed absence of BCL2 gene rearrangement. Despite the atypical immunophenotype and lack of BCL2 gene rearrangement, the diagnosis of follicular lymphoma was made based on careful observation of the morphology as well as immunoarchitecture of the Ki67, CD79a and CD21 markers.

Systematic Epstein-Barr virus-positive T-cell lymphoproliferative disease presenting as a persistent fever and cough: a case report.

INTRODUCTION: Systemic Epstein-Barr virus-positive T-cell lymphoproliferative childhood disease is an extremely rare disorder and classically arises following primary acute or chronic active Epstein-Barr virus infection. It is characterized by clonal proliferation of Epstein-Barr virus-infected T-cells with an activated cytotoxic phenotype. This disease has a rapid clinical course and is more frequent in Asia and South America, with relatively few cases being reported in Western countries. The clinical and pathological features of the disease overlap with other conditions including infectious mononucleosis, chronic active Epstein-Barr virus infection, hemophagocytic lymphohistiocytosis and natural killer cell malignancies. We describe the rare case of systemic Epstein-Barr virus-positive T-cell lymphoproliferative childhood disease in a 16-year-old Malay boy. CASE PRESENTATION: He presented with a six-month history of fever and cough, with pulmonary and mediastinal lymphadenopathy and severe pancytopenia. Medium- to large-sized, CD8+ and Epstein-Barr virus-encoded RNA-positive atypical lymphoid cells were present in the bone marrow aspirate. He subsequently developed fatal virus-associated hemophagocytic syndrome and died due to sepsis and multiorgan failure. CONCLUSIONS: Although systemic Epstein-Barr virus-positive T-cell lymphoproliferative childhood disease is a disorder which is rarely encountered in clinical practice, our case report underlines the importance of a comprehensive diagnostic approach in the management of this disease. A high level of awareness of the disease throughout the diagnosis process for young patients who present with systemic illness and hemophagocytic syndrome may be of great help for the clinical diagnosis of this disease.

An interesting case of systemic lupus erythematosus presenting with hypercalcemia: A diagnostic dilemma.

BACKGROUND: Hypercalcemia is common in primary hyperparathyroidism malignancies and even in tuberculosis. Interestingly, systemic lupus erythematosus (SLE) rarely presents with hypercalcemia. CASE REPORT: We describe an interesting case of SLE in a patient who was otherwise thought to have either tuberculosis or a malignancy. The patient initially presented with feeling unwell, with generalized lymphadenopathy, bilateral pleural effusion, and bilateral corneal calcium deposits secondary to severe hypercalcemia. The diagnosis of SLE was made based on positivity of antinuclear antibodies (ANA) and anti-dsDNA, the presence of serositis, lymphadenopathy, autoimmune hemolytic anemia, and constitutional symptoms. She was treated with steroids, with tremendous improvement in her general well-being, resolution of lymphadenopathy and pleural effusion, and normalization of her hemoglobin and serum calcium. The atypical presentation of SLE with hypercalcemia with pleural effusion is discussed. CONCLUSIONS: SLE should be one of the differential diagnoses in patients presenting with severe hypercalcemia.

Another look at follicular lymphoma: immunophenotypic and molecular analyses identify distinct follicular lymphoma subgroups.

AIMS: The aim of this study was to analyse the immunophenotypic and molecular features of a large series of follicular lymphomas, focusing in particular on atypical cases that fail to express CD10 and/or bcl-2. Such cases present diagnostic pitfalls, especially with regard to the differential diagnosis from follicular hyperplasia and marginal zone B-cell lymphoma. Therefore, we also included an immunohistochemical evaluation of stathmin, which is strongly expressed by germinal centre B cells, as a putative new marker for follicular lymphomas, particularly those with an atypical phenotype. METHODS AND RESULTS: Two hundred and five follicular lymphomas were investigated with immunohistochemistry and fluorescence in-situ hybridization (FISH). The use of three distinct anti-bcl-2 antibodies together with CD10 expression data and FISH analysis for bcl-2 and bcl-6 rearrangements allowed subclassification of follicular lymphoma into four distinct subgroups: (i) CD10-positive/bcl-2-positive, (ii) CD10-positive/bcl-2-negative, (iii) CD10-negative/bcl-2-positive, and (iv) CD10-negative/bcl-2-negative. All cases were bcl-6-positive. STMN1 (stathmin) was shown to be helpful in diagnosing bcl-2-negative and/or CD10-negative follicular lymphomas, and in their distinction from marginal zone B-cell lymphoma. CONCLUSIONS: Combined immunohistological and molecular analyses reveal that follicular lymphomas showing an atypical immunophenotypic and molecular profile exist, and we demonstrate that STMN1 represents a novel useful diagnostic marker for these.