V-raf murine sarcoma viral oncogene homolog B (BRAF) mutations in hairy cell leukaemia.

Introduction: Hairy cell leukemia (HCL) is a B-cell non-Hodgkin lymphoma with distinct clinical, morphological and immunophenotypic features; however, there are many other B-cell lymphomas, which closely mimic HCL. Accurate diagnosis of HCL is important as treatment with 2-chloro-2’-deoxyadenosine (cladribine) is associated with >80% chance of complete cure. The recent description of BRAF p.V600E mutations in almost all HCL cases in various studies has not only improved the pathogenetic understanding of this entity but also increased the diagnostic accuracy of this disorder. Aim: The aim of the study was to standardize a molecular test for diagnosis of HCL and compare with standard established morphological, cytochemical and immunophenotypic parameters for HCL diagnosis. Materials and Methods: The incidence of this mutation was sought in 20 patients with either classical HCL or HCL variant (HCLv) by Sanger sequencing and allele-specifi c polymerase chain reaction. BRAF p.V600E mutation was present in all HCL cases and absent in the only HCLv case. Results: A high degree of correlation was noted between the presence of BRAF p.V600E and established diagnostic criteria in 20/20 patients with HCL/ HCLv. Our data supports the observation that this mutation is present in all cases of HCL and is absent in HCLv. Hence, detection of the BRAF p. V600E mutation can be a useful adjunct in the diagnostic algorithm.

Fluorescence in situ hybridization patterns of BCR/ABL1 fusion in chronic myelogenous leukemia at diagnosis.

Background : Chronic myelogenous leukemia (CML) is characterised by the t(9;22)(q34;q11.2) which results in the formation of the BCR/ABL1 fusion gene. Occasionally, the t(9;22) may be associated with submicroscopic deletions of chromosomes 9 and/or 22 which appear to be associated with a worse prognosis. Three or four-way variant t(9;22) may also occur. All these changes as well as gain of the Philadelphia chromosome which represents disease progression can be detected by fluorescence in situ hybridization (FISH) analysis. FISH analysis at presentation is used to determine the number of cells with BCR/ABL1 fusion and establish whether the patterns are typical or atypical. Response to therapy can then be monitored by serial testing. Patients and Methods : The study group consisted of all patients diagnosed or suspected to have CML who had interphase FISH analysis at presentation on peripheral blood/bone marrow using a commercially available BCR/ABL1 dual colour, dual fusion probe. The study was performed at a tertiary hospital in India between 2004 and 2010. Results: There were 1076 diagnostic samples which were positive for BCR/ABL1 fusion. Typical dual fusion signals (two fusions, one red and one green, 2F1R1G) were seen in 801 cases (74 %). Atypical signal patterns were seen in 275 cases (26%). These were: 1F1R2G (4%), 1F2R1G (2.5%) and 1F1R1G (11%) representing deletions of the derivative 9 involving chromosome 9 sequences, chromosome 22 sequences, or both respectively; 3F1R1G (6.5%) usually representing gain of an additional Philadelphia chromosome and 1F2R2G (1%) representing a three- or four-way variant translocation. More than one signal pattern was seen in 1%. Conclusions: Our findings were similar to the literature with respect to the distribution of signal patterns except that we had a lower number of patients with variant translocations. While each signal pattern is typically associated with a particular abnormality, there can be more than one explanation for each pattern. Hence, metaphase FISH analysis is the "gold standard" for the interpretation of signal patterns.

Gonadoblastoma with unusual mixed germ cell overgrowth--a case report.

Gonadoblastoma is an uncommon tumour of ovary occurring exclusively in patients with inter sex disorders. We are presenting an unusual case of gonadoblastoma with distinctly rare pattern of germ cell overgrowth on the other side in an eighteen year old girl.