Primary central nervous system lymphoma: Comprehension of cell-of-origin subtypes

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is an uncommon extranodal lymphoma that accounts for more than 95% of all the CNS lymphomas. Unlike its systemic/nodal counterpart, which is currently subtyped into cell-of origin (COO) subtypes, its feasibility and utility are largely debatable in PCNS-DLBCL. Objectives: To classify PCNS-DLBCL into COO-subtypes based on immunohistochemical algorithms by Hans and Choi and evaluate concordance between the two. A further aim is to investigate the clinicoradiological and histomorphological parameters of the subtypes thus obtained. Materials and Methods: As many as 143 cases of primary CNS lymphoma were evaluated by immunohistochemistry for CD10, BCL6, MUM1, GCET, and FOXP1 and based on which the said 143 cases were further classified into COO subtypes using Hans and Choi algorithms. Results: Mean age was 53.8 years with marginal male preponderance and predominantly centroblastic morphology (75.5%). CD 10 was positive in 8.9% of the cases, BCL6 in 58.6%, MUM1 in 89.9%, GCET in 32.9%, and FOXP1 in 79.5%. As much as 84.9% cases were of non-germinal center B-cell (GCB) subtype and 15.1% cases were of GCB subtype as determined based on Hans algorithm. Furthermore, 90.7% cases were of activated B-cell (ABC) subtype and 9.3% cases were of GCB subtype according to Choi algorithm. A 91.8% concordance was observed between Hans and Choi algorithms. Among the 6 discordant cases, 5 cases were subtyped as GCB by Hans and ABC by Choi and 1 case as ABC by Hans and GCB by Choi. Conclusion: Most of PCNS-DLBCLs are of non-GCB/ABC COO subtype, but inconsistences abound in the utility of IHC algorithms in PCNS-DLBCL COO subtypes.

BRAFV600E mutation in hairy cell leukemia: A single-center experience

Background: BRAFV600E mutation has been reported as a unique genetic lesion of hairy cell leukemia (HCL), a subset of which lacks this lesion and shows adverse outcomes. Aims: To determine the prevalence of BRAFV600E in HCL from our center and derive clinicopathological correlation, if any. Materials and Methods: A 9-year retrospective analysis of 46 consecutive cases of HCL diagnosed on morphology and immunophenotyping was done. Stained smears were used as samples for amplification refractory mutation system polymerase-chain reaction using fluorescent primers for mutation detection. Results: BRAFV600E mutation was detected in 41/46 patients (89.1%) while absent in control samples of chronic lymphocytic leukemia. Cases mimicking HCL-variant clinically or immunophenotypically too showed the presence of this mutation. HCL with mutated BRAF presented at a younger age. No statistical difference in blood counts, tumor load, and immunophenotype patterns existed among BRAF mutated and unmutated group. Nine patients (45%) with mutated BRAF had residual disease following treatment with cladribine. Conclusion: BRAFV600E mutation analysis has a definitive role in the diagnosis of HCL.

Molecular genetics of BCR-ABL1 negative myeloproliferative neoplasms in India

Introduction: Over the past decade, we have moved on from a predominantly morphological and clinical classification of myeloproliferative neoplasms (MPN) to a more evolved classification that accounts for the molecular heterogeneity that is unique to this subgroup of hematological malignancies. This usually incorporates mutations in Janus kinase 2 (JAK2), MPL, and calreticulin (CALR) genes. In this manuscript, we report the frequency of these mutations in a cohort of Indian patients at a tertiary cancer center. Materials and Methods: One hundred and thirty cases of MPN were included in this study. These cases were diagnosed and classified based on the World Health Organization 2008 criteria. JAK2 and MPL mutations were detected using high sensitivity allele-specific polymerase chain reaction using fluorescent labeled primers followed by capillary electrophoresis. A subset of JAK2 and CALR mutations were assessed using a fragment length assay. Results: Among the MPN, we had 20 cases of polycythemia vera (PV), 34 cases of essential thrombocythemia (ET), and 59 of myelofibrosis (MF). JAK2, MPL, and CALR mutations were mutually exclusive of each other. Seventeen cases were categorized as MPN unclassifiable (MPN-U). JAK2p.V617F and MPL mutations were present in 60% (78 of 130) and 5.3% (7 of 130) of all MPN. All the PV cases harbored the JAK2 p.V617F mutation. A total of 23.8% (31 of 130) of patients harbored CALR mutations. CALR exon 9 mutations were detected in 60.8% (14 of 23) and 50% (5 of 10) of JAK2 and MPL negative MF and ET cases, respectively. MPN-U cases included three JAK2 p.V617F positive, two MPL p.W515 L, and 12 CALR positive cases. Ten different types of CALR indels (8 deletions and 2 insertions) were detected of which Type I and Type II mutations were the most common, occurring at a frequency of 45.1% (14 of 31) and 22.5% (7 of 31), respectively. Discussion and Conclusion: We report frequencies of JAK2 p. V617F, MPL exon 10 and CALR mutations in 130 patients similar to those reported in western literature. These mutations carry not only diagnostic but also prognostic relevance.

An unusual presentation of large B-cell lymphoma with interferon regulatory factor 4 gene rearrangement

Rearrangements involving interferon regulatory factor 4 (IRF4) gene has been recently described in a subtype of diffuse large B-cell lymphoma (DLBCL). They occur in a typical clinical setting of a pediatric age group, predominantly with tonsillar mass, usually as a low-stage disease and with good response to chemotherapy. Histomorphologically, they show nodular/follicular architecture with diffuse strong immunopositivity for multiple myeloma oncogene 1. Here, the authors describe one such unusual case of large B-cell lymphoma with IRF4 gene rearrangement in a young child with the unusual location of inguinal region and detailed pathological (histological, immunohistochemical, and molecular) findings.

Applicability of 2008 World Health Organization classification system of hematolymphoid neoplasms: Learning experiences

Background: 2008 World Health Organization (WHO) classification of hematolymphoid neoplasms (HLN) has classified them based on morphology, results of various ancillary techniques, and clinical features.[1] There are no studies looking at the applicability of WHO classification. Aims: The aim of the study was to calculate proportions of all HLN subtypes seen during 1-year period based on 2008 WHO classification of HLN and study applicability and also shortcomings of practices in a tertiary care center in India. Materials and Methods: This was a 1-year retrospective study (January 1st, to December 31st, 2010) where cases were identified using hospital/laboratory electronic records. Old follow-up and referral cases were excluded from the study. Only newly diagnosed cases classified into categories laid down by 2008 WHO classification of HLN included. Results: Out of 2118 newly diagnosed classifiable cases, 1602 (75.6%) cases were of lymphoid neoplasms, 489 (23.1%) cases of myeloid neoplasms, 16 (0.8%) cases of histiocytic and dendritic cell neoplasms, and 11 (0.5%) cases of acute leukemias of ambiguous lineage. Overall, most common HLN subtype was diffuse large B-cell lymphoma (n = 361, 17.0%). Precursor B-lymphoblastic leukaemia/lymphoma (n = 177, 48.2%) was the most common subtype within pediatric age group. Conclusions: All major subtypes of HLN were seen at our center and showed trends almost similar to those seen in other Indian studies. Molecular/cytogenetic studies could not be performed on a significant number of cases owing to logistic reasons (unavailability of complete panels and also cost-related issues) and such cases could not be classified as per the WHO classification system.

Clinico-pathological impact of cytogenetic subgroups in B-cell chronic lymphocytic leukemia: Experience from India.

BACKGROUND: The present study of 238 B‑cell Chronic Lymphocytic Leukemia (B‑CLL) patients were undertaken to seek the prevalence and to evaluate clinico‑pathological significance of recurrent genetic abnormalities such as del(13q14.3), trisomy 12, del(11q22.3) (ATM), TP53 deletion, del(6q21) and IgH translocation/deletion. MATERIALS AND METHODS: We applied interphase – fluorescence in situ hybridization (FISH) on total 238 cases of B‑CLL. RESULTS: Our study disclosed 69% of patients with genetic aberrations such as 13q deletion (63%), trisomy 12 (28%), 11q deletion (18%), 6q21 deletion (11%) with comparatively higher frequency of TP53 deletion (22%). Deletion 13q displayed as a most frequent sole abnormality. In group with coexistence of ≥2 aberrations, 13q deletion was a major clone indicating del(13q) as a primary event followed by 11q deletion, TP53 deletion, trisomy 12, 6q deletion as secondary progressive events. In comparison with del(13q), trisomy 12, group with coexistence of ≥2 aberrations associated with poor risk factors such as hyperleukocytosis, advanced stage, and multiple nodes involvement. In a separate study of 116 patients, analysis of IgH abnormalities revealed either partial deletion (24%) or translocation (5%) and were associated with del(13q), trisomy 12, TP53 and ATM deletion. Two of 7 cases had t(14;18), one case had t(8;14), and four cases had other variant IgH translocation t(?;14). CONCLUSION: Detail characterization and clinical impact are necessary to ensure that IgH translocation positive CLL is a distinct pathological entity. Our data suggests that CLL with various cytogenetic subsets, group with coexistence of ≥2 aberrations seems to be a complex cytogenetic subset, needs more attention to understand biological significance and to seek clinical impact for better management of disease.

Is there a role for metronomic induction (and maintenance) therapy in elderly patients with acute myeloid leukemia: A literature review.

Acute myeloid leukemia (AML) in older adults differs biologically and clinically from that in younger patients and is characterized by adverse chromosomal abnormalities, stronger intrinsic resistance, and lower tolerance to chemotherapy. In patients over age 60 with AML, cure rates are under 10% despite intensive chemotherapy, and most of them die within a year of diagnosis. Over the last decade, metronomic chemotherapy has emerged as a potential strategy to control advanced/ refractory cancer. Here, we report a case of a 68‑year‑old gentleman having AML with high‑risk cytogenetic features, who achieved complete remission on our oral metronomic PrET (PrET: Prednisolone, etoposide, thioguanine) protocol on an outpatient basis. He was later treated with standard high‑dose (HD) cytosine arabinoside (Ara‑C) consolidation followed by maintenance with etoposide, thioguanine, and sodium valproate. Presently, the patient is nearly 35 months since diagnosis and 21 months off treatment. This case report and review highlights that the combination of oral low‑intensity metronomic therapy, followed by standard HD consolidation therapy and metronomic maintenance therapy may be well tolerated by elderly patients especially with less proliferative, high (cytogenetic)‑risk AML who are otherwise deemed to be unfit for intensive intravenous induction chemotherapy regimens. References for this review were identified through searches of Pubmed for recent publications on the subject as well as searches of the files of the authors themselves. The final list was generated on the basis of originality and relevance to this review.

Study of the morphological patterns and association of Epstein-Barr virus and human herpes virus 8 in acquired immunodeficiency deficiency syndrome-related reactive lymphadenopathy.

Aims: Study of the morphological patterns of acquired immunodeficiency syndrome (AIDS)-related lymphadenopathy. Settings and Design: We retrospectively selected cases of AIDS-related benign lymphadenopathy. Cases with lymphomas, frank granulomas and necrosis were excluded. We analyzed different morphological patterns and correlated these with immunophenotypic markers along with viral markers human herpesvirus 8-latency-associated nuclear antigen (HHV8-LANA), and Epstein-Barr virus-encoded ribonucleic acid (EBER) studies via in situ hybridization (EBER-ISH). Materials and Methods: We present the morphological patterns of 13 cases of human immunodeficiency virus (HIV)-reactive lymph nodes and their clinical, hematological, biochemical and radiological parameters with special emphasis on the presence or absence of viral markers, including HHV8 and EBV. Results: Common patterns included follicular hyperplasia only (five cases), mixed pattern of follicular hyperplasia with burnt-out germinal centres (four cases), completely atretic follicle (two cases), folliculolysis (11 cases), dumbbell-shaped follicles (three each), progressive transformation of germinal centers (four cases), T-zone expansion (two cases), Reed Sternberg (RS) cells like immunoblasts (two cases), Castleman's-like features with lollipop-like follicles (three cases) and a spindle cell prominence (one case). CD8+ T-cells were predominant in 12 cases. CD8+ T-cells were prominent in germinal centers (eight cases). Plasmablasts were seen in four cases within the perigerminal center area. Immunohistochemistry for HHV8, i.e. HHV8-LANA were negative in all cases while EBER was detected in 11 cases in the centrocyte-like B cells. Two cases of multicentric Castleman's disease expressed EBER; however, they did not express HHV8. Conclusion: The wide spectrum of histological changes in HIV-associated lymphadenopathy requires recognition. The histological changes can mimic those of other infective lymphadenitis, follicular lymphoma, Castleman's disease, progressive transformation of germinal center, Hodgkin's disease and spindle cell neoplasms. Presence of EBV is common while HHV8 was not seen.

Immunophenotyping of mature T/NK cell neoplasm presenting as leukemia.

Introduction : Mature T/NK cell lymphomas (MTNKL) presenting as leukemia are rare and show considerable overlapping of clinical, morphological and immunophenotypic features. AIM: Critical analysis of the morphology and immunophenotypic profile of MTNKL. Materials and Methods : We reviewed 380 consecutive cases of mature lymphoid neoplasm that presented as leukemia and were diagnosed on morphology and immunophenotyping of bone marrow and/or peripheral blood samples. Results : Peripheral blood and bone marrow involvement was seen in all cases. MTNKL constituted 4% (nine cases) of all mature lymphoid neoplasms presenting as leukemia. It included four cases of T-large granular leukemia (T-LGL), two of T-cell prolymphocytic leukemia small cell variant (T-PLL), two of adult T-cell leukemia/lymphoma (ATLL) and one of primary cutaneous gamma delta T-cell lymphoma (PCGDTCL). T-LGL revealed CD4-/CD8+ phenotype in three, and CD4+/CD8+ phenotype in one case. CD56 was absent in all the cases of T-LGL. One case of T- PLL small cell variant showed CD4+/CD8- phenotype, while the other revealed CD4-/CD8+ phenotype. Both cases of ATLL showed CD4+/CD8+/CD25+ phenotype. The single case of PCGDTCL showed CD4-/CD8- phenotype pattern. CD3 and CD5 were expressed in all MTNKL. CD7 was absent in three cases of T-LGL. TCRα/β was performed in three cases of T-LGL and was positive in all. TCRα/β was also seen in both the cases of T-PLL small variant. However, TCRα/β was seen in the single case of PCGDTCL. Conclusion : Mature nodal T/NK cell neoplasms are rare and MTNKL presenting as leukemia are even rarer. There is an overlap between the immunophenotypic profiles of different MTNKL subtypes and elaborate T/NK cell panels are required for their evaluation.

Positron emission tomography / computerized tomography evaluation of primary Hodgkin's disease of liver.

Occurrence of primary Hodgkin's lymphoma (PHL) of the liver is extremely rare. We report on a case of a 60-year-old male who presented with liver mass and B-symptomatology. Hepatoma or hepatic metastasis from a gastrointestinal primary was initially suspected. Tumor markers like AFP, CEA, Total PSA, and CA-19.9 were within normal limits. Positron Emission Tomography / Computerized Tomography (PET/CT) revealed a large hepatic lesion and a nodal mass in the porta hepatis. A liver biopsy was consistent with Hodgkin's lymphoma. There was complete regression of the hepatic lesion and evidence of shrinkage of the nodal mass following four cycles of chemotherapy. 18F Fluro -de-oxy Glucose (FDG) PET / CT in this case helped in establishing a primary hepatic lymphoma by demonstrating the absence of pathologically hypermetabolic foci in any other nodes or organs. PET / CT scan is a useful adjunct to conventional imaging and histopathology, not only to establish the initial diagnosis, but also to monitor treatment response in PHL.

Clinico-hematological profile in biphenotypic acute leukemia.

BACKGROUND: We present a clinico-hematological profile and treatment outcome of Biphenotypic Acute Leukemia (BAL). AIM: Study incidence and subtypes of BAL, correlate with age, morphology, and cytogenetic findings and correlate the clinico-hematological data with the treatment response. St Jude's and the EGIL's criteria have been compared for their diagnostic and clinical relevance. MATERIAL AND METHODS: Diagnosis was based on WHO classification, including clinical details, morphology, cytochemistry, immunophenotyping, and molecular genetics. We included those cases, which fulfilled the European Group for the Immunological Characterization of Acute Leukemia's (EGIL's) scoring system criteria for the diagnosis of BAL, as per recommendation of the WHO classification. RESULTS: There were 32 patients diagnosed with BAL, based on EGIL's criteria. Incidence of BAL was 1.2%. B-Myeloid (14 cases) followed by T-Myeloid BAL (13 cases) were the commonest subtypes. Polymorphous population of blasts (16 cases) was commonly associated with T-Myeloid BAL (10 cases). BCR ABL fusion positivity was a common cytogenetic abnormality (seven cases). Fifteen patients received chemotherapy; eight achieved complete remission (CR) at the end of the induction period. CONCLUSIONS: Pediatric BAL and T-B lymphoid BAL have a better prognosis. A comprehensive panel of reagents is required, including cytoplasmic markers; to diagnose BAL. St Jude's criteria is a simple, easy, and cost-effective method to diagnose BAL. The outcome-related prognostic factors include age, HLA-DR, CD34 negativity, and subtype of BAL. BCR-ABL expression is an important prognostic factor, as these cases will be labeled as Chronic myeloid leukemia (CML) in blast crisis with biphenotypic expression and treated accordingly.

A clinicopathologic study of mantle cell lymphoma in a single center study in India.

We present clinical features, histopathology and results of treatment in cases of mantle cell lymphoma (MCL) at our hospital. We had 93 cases (2.1%) of MCL out of total 4301 cases of non-Hodgkin's lymphoma (NHL) in a 4-year period. It included 68 cases (1.7%) of MCL from 3987 cases of NHL diagnosed on histopathology. Remaining 25 cases (7.9%) diagnosed solely on peripheral blood examination were excluded. Thirty-six (85%) patients had advanced-stage disease. Sixty-three were nodal and five were extranodal (all gastrointestinal tract). Common patterns were diffuse (64%), nodular (25%) and mantle zone type (11%). Sixty-two cases had lymphocytic while six had blastic morphology (all nodal). Tumor cells expressed CD20 (100%), CD43 (94%), CD5 (89%) and cyclin D1 (85%). Bone marrow was involved in 25 (59%) cases. Thirty-two patients could be treated. Median recurrence-free survival was 22.23 months. Diffuse pattern of nodal involvement had a lower overall survival.

Fludarabine in lymphoproliferative malignancies: a single-centre experience.

BACKGROUND: Fludarabine has been reported to be an effective drug for the treatment of chronic lymphocytic leukaemia (CLL) and indolent lymphomas. However, its safety and efficacy in Indian patients has not been studied. We retrospectively analysed our experience with fludarabine in low grade lymphomas and CLL. METHODS: The records of all patients with low grade lymphoma or CLL who received fludarabine between April 1999 and November 2006 were analysed. Response evaluation was done as per the National Cancer Institute-Working Group guidelines for CLL and International Workshop criteria for non-Hodgkin lymphomas, respectively, in those patients who received at least 3 cycles of fludarabine. Toxicity was graded as per the common terminology criteria for adverse events, version 3.0. Median event-free survival was obtained using Kaplan-Meier survival analysis. RESULTS: Forty-seven patients were included in the study and 189 cycles were administered (median: 4 cycles per patient). Sixteen patients had a treatment delay, 14 due to myelosuppression. Twenty-five patients had low grade lymphoma and 22 had CLL. The response was evaluable in 22 patients with low grade lymphoma and 20 with CLL. The overall response rate for CLL was 100% in those treated upfront (n=9) and 55% in those with relapsed disease (n=11). The overall response rate for low grade lymphoma was 88% (63% complete remission) in untreated patients and 79% (43% complete remission) in those with relapsed disease. Common adverse events were myelosuppression and infection. Two patients died of sepsis and 4 due to disease progression on treatment. Median event-free survival for patients treated upfront with fludarabine was 31.4 months. CONCLUSION: In our patient population, response to fludarabine is similar to that in the published literature. Our patients had a higher frequency of haematological toxicity.

Leiomyosarcoma of the maxilla as second malignancy in retinoblastoma.

Patients with hereditary retinoblastoma are at increased risk of second primary tumor, the commonest tumor being osteosarcoma. Leiomyosarcoma developing as second primary neoplasm in retinoblastoma patients is unusual and most have occurred in the field of previous radiotherapy. Although with aggressive therapy better survival can be achieved, the overall prognosis of patients developing these second neoplasms is poor. In this report we present a case of leiomyosarcoma of the maxilla as a second neoplasm in a patient with bilateral retinoblastoma which has developed outside the radiation field.

Bone marrow morphological changes in patients of chronic myeloid leukemia treated with imatinib mesylate.

Background: Imatinib mesylate has shown promising results in chronic myeloid leukemia (CML) in all phases. This drug is an effective treatment for patients with CML in chronic phase as it induces hematological remission in nearly all patients and cytogenetic responses in many. The bone marrow changes produced by this drug are different from the treatment modalities used earlier in CML. Materials & Methods: We studied 80 patients of CML on treatment with Imatinib at doses of 400-800 mg per day. Morphological and cytogenetic evaluation (Ph analysis) of bone marrow aspirates was done at six months of treatment. Result: In our study, 95% (76 out of 80) patients showed complete hematological response and 63.3% showed major cytogenetic response at the end of six months of treatment. The most commonly observed changes in the bone marrow aspirates at the end of six months of therapy were in the form of reduction in the cellularity, reduction in the M: E ratio to a mean of 2:1, presence of relative erythroid hyperplasia, normalization of megakaryocytic morphology and variable increase in the bone marrow lymphocytes. None of these changes had significant correlation with the patient's Ph status. Conclusion: We advise study of trephine biopsies to overcome the often-faced problem of hemodiluted aspirates in these cases and evaluation of sequential bone marrows to check the durability of these morphological changes and their correlation with the cytogenetic response with emphasis on cytogenetic changes other than Ph positivity.

Morphological spectrum of AIDS-related plasmablastic lymphomas.

We have had a recent spurt in cases of AIDS-related lymphoma (ARL) at our centre. Most of these cases are aggressive mature B cell lymphomas, mainly plasmablastic lymphoma (PBL) and diffuse large B-cell lymphoma (DLBCL). Most of the PBL are extranodal in location and are mucosa-based. We reviewed the morphological features of 34 cases of PBL. Diagnosis was based on morphology, immunohistochemistry, proliferation index, HIV positive status and its preference to extranodal sites (mostly mucosa based). We classified PBL into three morphological subtypes (immunoblastic - 25, Burkitt's - 7, plasmacytic - 2). Tumor cells expressed as leucocyte common antigen (LCA) in 60%, CD138 in 100%, EMA in 45% and light chain restriction in 86% cases. CD20 was negative in all cases. Pathologists need to be aware of PBL and its various morphological subtypes as the identification of this entity from its close differentials carries major therapeutic implications.

Anaplastic large cell lymphoma (ALCL) presenting as primary bone and soft tissue sarcoma--a study of 12 cases.

This study highlights the rare presentation of anaplastic large cell lymphoma as primary bone and soft tissue tumour. Twelve cases were studied. Clinical impression was non Hodgkin's lymphoma in 4 cases, sarcoma in 6 (osteosarcoma-2, Ewing's/primitive neuroectodermal tumour-1, and sarcoma NOS-3), and tuberculosis of thoracic spine in 1 and the last case involving the rib had a differential diagnosis of tuberculosis and NHL. Histology revealed round cells with eosinophilic cytoplasm and pleomorphic nuclei. Immunohistochemically all tumours were CD30 positive and 8 of 9 cases (88.9%) showed ALK-1 positivity. The pleomorphic cytomorphology ofALCL leads to confusion with the more frequent bone and soft tissue sarcomas affecting the musculoskeletal system. A high index of suspicion is necessary to initiate the correct panel of immunohistochemical markers to first confirm the lymphomatous nature of this tumour and to subsequently subclassify. This alone will lead to an accurate recognition of ALCL and the appropriate chemotherapy.

Follicular dendritic cell tumour of tonsil - is it an under-diagnosed entity?

Neoplasms of follicular dendritic cells are uncommon and while majority of them occur in lymph nodes, they are increasingly recognized at varied sites such as abdominal viscera. Tonsil is the most common extra nodal site for occurrence of FDCT in the head and neck region. We describe three cases of follicular dendritic cell tumour occurring in the tonsil.