Concurrent Presentation of Hairy Cell Leukemia and Mantle Cell Lymphoma (Leukemic Non-Nodal Variant): An Extremely Rare Composite Lymphoma.

Herein, we describe the clinicopathologic and genetic characteristics of the first report of simultaneous bone marrow involvement by classical hairy cell leukemia (HCL) and leukemic non-nodal variant of mantle cell lymphoma (L-NN-MCL) with t(11;14)(q13;q32) with BRAF mutation and deletion of TP53. A 40-year-old asymptomatic man was investigated for incidental neutropenia and thrombocytopenia. Flow cytometry showed two distinct monotypic B-cell populations: one expressed CD19 (bright), CD20 (bright), FMC7, CD103, CD25, CD11c, CD123, and IgD (bright) and showed kappa light chain restriction (bright), consistent with HCL and the other kappa-restricted CD5/CD10-negative B-cell population with distinctive immunophenotypic features. The bone marrow biopsy is infiltrated by an abnormal B-lymphoid infiltrate with different patterns of infiltration in different marrow areas. Fluorescence in situ hybridization (FISH) analysis revealed a CCND1/IGH rearrangement, t(11;14)(q13;q32), and deletion of TP53. The BRAF V600E missense mutation was detected by quantitative real-time polymerase chain reaction (PCR). The diagnosis of a composite B-cell neoplasm was composed of HCL together with a second CD5/CD10-negative monotypic B-cell population, with CCND1/IGH fusion, favoring the 2016 WHO new category of L-NN-MCL (CD5/SOX11-negative). Treatment with cladribine and rituximab normalized the blood counts within 6 weeks without significant side effects. L-NN-MCL is one of the smoldering MCL subtypes, recently listed in WHO 2016 as a separate variant, with a particular set of unique features and a less aggressive clinical course compared to classical MCL. To date, the clinicopathological features (including the bone marrow findings) of L-NN-MCL have not been sufficiently characterized in the literature. We describe the first report of synchronous presentation of HCL and L-NN-MCL. This case represents a real challenge from the biologic, diagnostic and therapeutic point of views, due to extremely rare combination of two distinct uncommon B-cell neoplasms. The study of composite lymphomas offers the opportunity to evaluate the etiology and the clonal interrelationship involved in the pathogenesis/evolution of lymphomas.

Status of HER2 amplification, polysomy 17 and histopathological features of 425 Pakistani breast cancer patients.

HER2 gene amplification in invasive breast cancer is a robust predictive marker for response to transtuzumab therapy. This study was undertaken to measure concordance between immunohistochemistry (IHC) and FISH for HER2 gene amplification in invasive breast tumors, as well as the presence of polysomy 17 and possible correlation with demographics and histopathological variables, including ER and PR positivity. A total of 425 cases of infiltrating carcinoma of breast (99% IDC-NOS) were studied. HER2 over expression was tested by IHC and FISH methods. Association between IHC and FISH in both subsets was calculated by amplification ratio including polysomy 17. Out of 425 specimens, 128 (30%) were positive for HER2 amplification by FISH test, whereas only 78 (24%) tumors with 2+ expression showed amplification. In contrast, 39 (74%) demonstrated 3+ IHC score and HER2 gene amplification. The histological variables including tumor size, tumor type, and lymph node involvement did not influence the outcome of FISH analysis. The ER and PR status showed significantly greater positivity in patients negative for HER2 amplification. Polysomy 17 was detected in 23.7% patients and was positively associated with ER and PR expression (P= <0.05). Our study showed a concordance of 24% between 2+ IHC and FISH amplification, while in 3+ IHC cases the concordance was 74%. Significant links of HER2 amplification was seen with ER andPR negativity and higher tumor grade. In addition, non-significant correlations were noted with other variables like tumor type, size and lymph node status.

Analysis of amniotic fluid specimens for common chromosome disorders using interphase fluorescence in situ hybridization.

OBJECTIVE: The aim of the study was to examine the usage of multi colour FISH technology as an adjunct to conventional cytogenetics for the prenatal diagnosis of aneuploidy in interphase nuclei from high risk pregnancies. METHODS: Amniotic fluid samples were collected for interphase FISH analysis using DNA probes for chromosomes 13, 18, 21, X and Y. All the probes were directly labeled with fluorescent molecules. Fluorescent signals were observed under a microscope. A minimum of 100 nuclei with defined hybridization signals were counted for each probe. RESULTS: Seventy-eight amniotic fluid samples were received for FISH analysis. The average age of mothers and their gestational ages were 33 years and 17.5 weeks respectively. Triple test screening was positive in 39.5% of the women followed by advanced maternal age and ultrasonographic abnormalities. Interphase FISH was performed on 76 specimens whereas 2 samples were rejected because of blood contamination. Aneuploidy was identified in 6 out of 76 specimens. Two cases of trisomy 21, two cases of trisomy 18 and one case of monosomy X were detected. In addition, one case showed 10% mosaicism for trisomy 21. Initially 4 (5.3%) samples were uninformative due to technical reasons but gave acceptable scoring signals when reanalyzed. CONCLUSION: This study has demonstrated that interphase FISH is a rapid and a reliable technique for the enumeration of chromosome number in uncultured amniocytes. Clinicians can use it for making early decisions necessary for the management of high risk pregnancies ultimately saving patients from anxiety and psychological stress.

Immunohistochemical her-2/ Neu expression with gene amplification by fluorescence in situ hybridization for assessment in breast carcinomas.

OBJECTIVE: To compare gene amplification of HER-2/neu gene by fluorescence in situ hybridization (FISH) in moderate to strong immunohistochemically (IHS) positive HER-2/neu cases of invasive breast carcinomas. STUDY DESIGN: Cross- sectional study. PLACE AND DURATION OF STUDY: Section of Histopathology, The Aga Khan University Hospital, Karachi, from January 2004 to December 2006. PATIENTS AND METHODS: Forty one (41) diagnosed cases of invasive breast carcinomas were included in this study in which already determined immunohistochemical HER-2/neu expression was scored as either 2+ or 3+, based on the intensity of membranous staining. These cases were further evaluated for gene amplification by FISH. For gene amplification, a ratio of HER-2/CEP Z 2 was accepted as positive gene amplification. RESULTS: Out of a total 41 cases, which were scored as 2+ and 3+ by IHC, 14 cases (34.1%; 95% confidence interval: 19%-49.3% ) showed gene amplification by FISH. Proportion of FISH positivity in IHC 2+ cases alone was found to be 25% (95% confidence interval: 10.5%-41%). In contrast, a majority of IHC 3+ cases (5 of 6) were positive by FISH studies. CONCLUSION: IHC is appropriate for initial HER-2/neu assessment and patients with tumors scored as 3+ may be treated alone based on this information provided strict quality control and 95% concordance with FISH assays; however, patients with tumors interpreted as 2+, would benefit from gene amplification by FISH studies for more accurate assessment to avoid inaccurate prognostication and treatment.