Correlation between FDG/PET, histology, characteristics, and survival in 332 patients with chronic lymphoid leukemia

How I manage CLL with venetoclax-based treatments

Targeted therapies for chronic lymphocytic leukemia (CLL) include venetoclax, the oral inhibitor of B-cell lymphoma-2, and inhibitors of kinases in the B-cell receptor signaling pathway, like Bruton tyrosine kinase and phosphatidylinositol 3 kinase. Randomized clinical trials clearly demonstrated improved progression-free survival with targeted therapy over chemoimmunotherapy in first-line and treatment of relapsed/refractory CLL. Comparative trials of venetoclax-based vs other targeted therapies have not been conducted. Differentiating features and considerations with targeted therapies include goals of treatment and therapeutic approach as well as side effect and toxicity profiles. With targeted therapy options for first-line and relapsed CLL, it is ever more important to develop sound rationale and strategy for selecting first-line and treatment of relapsed disease and for long-term management of the disease, including therapeutic sequencing. Fixed-duration therapy with a treatment-free remission is a particularly appealing prospect, since it avoids continuous exposure to treatment and potential for toxicity. We discuss rationale and practical application of venetoclax in first-line and treatment of relapsed and refractory CLL. Venetoclax is highly active at achieving deep remission for most treated patients with CLL, including those with high-risk disease such as del(17p) CLL.

Leukemic Involvement in the Thorax

Leukemias are malignancies in which abnormal white blood cells are produced in the bone marrow, resulting in compromise of normal bone marrow hematopoiesis and subsequent cytopenias. Leukemias are classified as myeloid or lymphoid depending on the type of abnormal cells produced and as acute or chronic according to cellular maturity. The four major types of leukemia are acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and chronic lymphocytic leukemia. Clinical manifestations are due to either bone marrow suppression (anemia, thrombocytopenia, or neutropenia) or leukemic organ infiltration. Imaging manifestations of leukemia in the thorax are myriad. While lymphadenopathy is the most common manifestation of intrathoracic leukemia, leukemia may also involve the lungs, pleura, heart, and bones and soft tissues. Myeloid sarcomas occur in 5%-7% of patients with acute myeloid leukemia and represent masses of myeloid blast cells in an extramedullary location. ^©RSNA, 2019.

Multiple B cell malignancies in patients with chronic lymphocytic leukemia: epidemiology, pathology, and clinical implications

Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is associated with increased risk for certain cancers, but relatively little is known about the risk for these patients to develop additional B cell malignancies. Here, we review the available epidemiological data on multiple B cell malignancies in CLL, discuss diagnostic methods and proper pathologic evaluation to distinguish CLL from other B cell malignancies, and address clinical challenges and unmet needs in caring for CLL patients with unrelated B cell malignancies and disease transformation. Considerations include CLL patients with unrelated monoclonal B cell lymphocytosis, biclonal CLL, secondary B cell non-Hodgkin lymphomas, and Richter syndrome - both clonally related transformation and de novo large B cell lymphoma. We address the challenges that remain in order to better understand the underlying risk factors and biology that may put CLL patients at increased risk of developing multiple B cell neoplasia.

Pre-treatment maximum standardized uptake value predicts outcome after frontline therapy in patients with advanced stage follicular lymphoma

The impact of pre-treatment maximum standardized uptake value (SUV_max) on the outcome of follicular lymphoma (FL) following specific frontline regimens has not been explored. We performed a retrospective analysis of 346 patients with advanced stage follicular lymphoma (FL) without histological evidence of transformation, and analyzed the impact of SUV_max on outcome after frontline therapy. Fifty-two (15%) patients had a SUV_max >18, and a large lymph node ≥6 cm was the only factor associating with SUV_max >18 on multivariate analysis (odds ratio 2.7, 95% confidence interval [CI]: 1.3-5.3, P=0.006). The complete response rate was significantly lower among patients treated with non-anthracycline-based regimens if SUV_max was >18 (45% vs. 92%, P<0.001), but not among patients treated with R-CHOP (P=1). SUV_max >18 was associated with significantly shorter progression-free survival among patients treated with non-anthracycline-based regimens (77 months vs. not reached, P=0.02), but not among patients treated with R-CHOP (P=0.73). SUV_max >18 associated with shorter overall survival (OS) both in patients treated with R-CHOP (8-year OS 70% vs. 90%, P=0.02) and non-anthracycline-based frontline regimens (8-year OS 50% vs. 85%, P=0.001). In conclusion, pre-treatment PET scan has prognostic and predictive value in patients with advanced stage FL receiving frontline treatment.

Is percutaneous computed tomography-guided biopsy sufficient to establish indolent lymphoma transformation?

INTRODUCTION

The aim of the study was to retrospectively evaluate the technical features, efficacy, accuracy, and relevant complications of computed tomography-guided biopsies in various anatomical localizations when diagnosing indolent lymphoma transformations, relapses, duplicate malignant diseases or benign processes.

MATERIAL AND METHODS

From December 2007 to December 2017, 81 percutaneous biopsy procedures in 72 patients for tumors, sizes 17-232 mm in diameter (median length: 39 mm), were performed in patients with known indolent lymphomas in their clinical history. The patients were men in 41 cases and women in 31 cases, aged 36 to 86 years.

RESULTS

In 79 cases (97.5%; 95% CI: 91.3-99.7) results were true positive or true negative; only 2 interventions (2.5%; 95% CI: 0.3-8.6) were histologically false negative. Transformation was verified in 29 cases (35.8%; 95% CI: 25.4-47.2), relapses in 30 cases (37%; 95% CI: 26.6-48.5), duplicate malignancy in 15 cases (18.5%; 95% CI: 10.8-28.7) and benign processes in 7 cases (8.7%; 95% CI: 3.5-17.0). Eight complications in total were revealed, 7 of which were in consequence of thoracic cavity biopsy. A statistically significant relationship between the complication incidence and anatomical localization in the thoracic cavity was identified (p = 0.0104).

CONCLUSIONS

Percutaneous CT guided biopsy performed in patients with a history of indolent lymphoma had high accuracy in establishing the correct diagnosis regarding transformation, relapse, duplicate malignancy or a benign process. Simultaneously, the complication rate was low.

Molecular Imaging in Oncology Using Positron Emission Tomography

BACKGROUND

Anatomical and molecular data can be acquired simultaneously through the use of positron emission tomography (PET) in combination with computed tomography (CT) or magnetic resonance imaging (MRI) as a hybrid technique. A variety of radiopharmaceuticals can be used to characterize various metabolic processes or to visualize the expression of receptors, enzymes, and other molecular target structures.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on guidelines from Germany and abroad and on systematic reviews and meta-analyses.

RESULTS

Established radiopharmaceuticals for PET, such as 2-[18F]fluoro-2- deoxyglucose ([18F]FDG), enable the visualization of physiological processes on the molecular level and can provide vital information for clinical decision-making. For example, PET can be used to evaluate pulmonary nodules for malignancy with 95% sensitivity and 82% specificity. It can be used both for initial staging and for the guidance of further treatment. Alongside the PET radiopharmaceuticals that have already been well studied and evaluated, newer ones are increasingly becoming available for the noninvasive phenotyping of tumor diseases, e.g., for analyzing the expression of prostate-specific membrane antigen (PSMA), of somatostatin receptors, or of chemokine receptors on tumor cells.

CONCLUSION

PET is an important component of diagnostic algorithms in oncology. It can help make diagnosis more precise and treatment more individualized. An increasing number of PET radiopharmaceuticals are now expanding the available options for imaging. Many radiopharmaceuticals can be used not only for noninvasive analysis of the expression of therapeutically relevant target structures, but also for the ensuing, target-directed treatment with radionuclides.

Tumor Metabolism as a Regulator of Tumor-Host Interactions in the B-Cell Lymphoma Microenvironment-Fueling Progression and Novel Brakes for Therapy

Tumor metabolism and its specific alterations have become an integral part of understanding functional alterations leading to malignant transformation and maintaining cancer progression. Here, we review the metabolic changes in B-cell neoplasia, focusing on the effects of tumor metabolism on the tumor microenvironment (TME). Particularly, innate and adaptive immune responses are regulated by metabolites in the TME such as lactate. With steadily increasing therapeutic options implicating or utilizing the TME, it has become essential to address the metabolic alterations in B-cell malignancy for therapeutic approaches. In this review, we discuss metabolic alterations of B-cell lymphoma, consequences for currently used therapy regimens, and novel approaches specifically targeting metabolism in the TME.

PD-1 Expression in Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) and Large B-cell Richter Transformation (DLBCL-RT): A Characteristic Feature of DLBCL-RT and Potential Surrogate Marker for Clonal Relatedness

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a low-grade B-cell neoplasm and ∼2% to 9% patients develop an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (Richter transformation, DLBCL-RT). Programmed death-1 (PD-1) pathway plays a crucial role in tumor host immunity evasion and its blockade has emerged as an effective anti-cancer immunotherapy. PD-L1 and PD-1 expression has shown predictive value in anti-PD cancer immunotherapy; however, it has not been well documented in CLL/SLL and DLBCL-RT. We evaluated PD-1 and PD-L1 expression by immunohistochemistry in 39 CLL/SLL, 15 DLBCL-RT, and 26 other DLBCL. In CLL/SLL, neoplastic B-cell PD-1 expression was weak and restricted to prolymphocytes/paraimmunoblasts within proliferation centers (PCs) and accentuated PCs of all sizes. Neoplastic B-cell PD-1 expression was highly prevalent and demonstrated increased intensity in DLBCL-RT, but in contrast was only rarely seen in other DLBCL (12/15 vs. 1/26; P<0.0001). An excellent correlation (90% concordance) was observed between neoplastic B-cell PD-1 immunohistochemistry positivity and molecularly defined CLL/SLL clonal relatedness in DLBCL-RT. PD-L1 expression was observed on the neoplastic B cells in rare DLBCL-RT and other DLBCL cases (1/15 vs. 1/26; P>0.05) as well as background histiocytes and dendritic cells. Overall survival of DLBCL-RT was significantly inferior to that of the other DLBCL (median, 16.9 vs. 106.1 mo; P=0.002). Our findings suggest a biological continuum from prolymphocytes/paraimmunoblasts in CLL/SLL PCs to the neoplastic B-cells in DLBCL-RT. The characteristic PD-1 expression in DLBCL-RT makes it a potential surrogate marker for determining clonal relatedness to CLL/SLL, which may have important prognostic and therapeutic implications.

PET/Computed Tomography in Chronic Lymphocytic Leukemia and Richter Transformation

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the United States. In 1-10% of cases, it can undergo Richter's transformation (RT) to either diffuse large B cell lymphoma (DLBCL) or Hodgkin's lymphoma (HL). Diagnosis requires histologic confirmation by tissue biopsy. PET/CT has been studied to in several series to look at its predictive value for identifying RT in biopsies. in this review, we will discuss the role of PET/CT to identify RT in patients CLL and its utility in clinical practice.

The clinical study on treatment of CD19-directed chimeric antigen receptor-modified T cells in a case of refractory Richter syndrome

Richter syndrome (RS) indicates the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma (mostly DLBCL). Richter syndrome is a rare complication with an aggressive clinical course, bearing an unfavorable prognosis. Currently, there is no effective treatment for it. As a novel cellular‐based immune therapy, chimeric antigen receptor‐modified T (CART) cells treatment is gradually used in treating hematological malignancies, especially in CD19⁺ B‐cell malignancy. Therefore, CD19‐directed chimeric antigen receptor‐modified T cells (CART‐19) treatment is promising to be used as a new method for RS patients. In our study, one RS patient expressing high level of CD19 molecule was enrolled in clinical trial; he has received a series of treatments but did not achieve a satisfactory therapeutic effect. The patient totally received 3.55 × 10⁸ autologous CART‐19 cells infusion. After CART‐19 infusion, the mainly clinical side effect was repeated fever. The maximal duration period was 24 days and the highest temperature was 40.1°C. Pancytopenia and significantly serum cytokines level rise were observed, including IFN‐γ, IL‐6, and IL‐10. Before discharge, the level of cytokines reduced to normal levels. In addition, we detected the serum biochemical indices as like K⁺, Ca²⁺, creatinine, and glutamic‐pyruvic transaminase, all of these indices were normal. This showed that there was no tumor necrosis syndrome after treatment. The proportion of B cells in patient's peripheral blood decreased from 72% to 40.2% after infusion, co‐occurring with reduction in lymph nodes and hematopoietic reconstitution. Based on the recent revolution in the therapeutic landscape for hematological malignancies including B‐cell lymphomas, CART‐CD19 cell therapy as a new therapeutic option for RS might be available in the coming years. It aims to reduce patient's tumor burden, prolong their survival time, and provide opportunities for other sequential therapy such as chemotherapy and bone marrow transplantation.

Utility of positron emission tomography-computed tomography in patients with chronic lymphocytic leukemia following B-cell receptor pathway inhibitor therapy

The utility of positron emission tomography-computed tomography (PET-CT) in distinguishing Richter’s transformation versus chronic lymphocytic leukemia (CLL) progression after ibrutinib and/or idelalisib was assessed in a post hoc analysis of a phase II study of venetoclax. Patients underwent PET-CT at screening and were not enrolled/treated if Richter’s transformation was confirmed pathologically. Of 167 patients screened, 57 met criteria for biopsy after PET-CT. Of 35 patients who underwent biopsy, eight had Richter’s transformation, two had another malignancy, and 25 had CLL. A PET-CT maximum standardized uptake value (SUVmax) ≥10 had 71% sensitivity and 50% specificity for detecting Richter’s transformation [Odds Ratio (OR): 2.5, 95%CI: 0.4-15; P=0.318]. Response rate to venetoclax was similar for screening SUVmax <10 versus ≥10 (65% vs. 62%) (n=127 enrolled), though median progression-free survival was longer at <10 months (24.7 vs. 15.4 months; P=0.0335). Six patients developed Richter’s transformation on venetoclax, of whom two had screening biopsy demonstrating CLL (others did not have a biopsy) and five had screening SUVmax <10. We have defined the test characteristics for PET-CT to distinguish progression of CLL as compared to Richter’s transformation when biopsied in patients treated with B-cell receptor signaling pathway inhibitors. Overall diminished sensitivity and specificity as compared to prior reports of patients treated with chemotherapy/chemoimmunotherapy suggest it has diminished ability to discriminate these two diagnoses using a SUVmax ≥10 cutoff. This cutoff did not identify venetoclax-treated patients with an inferior response but may be predictive of inferior progression-free survival. (Registered at clinicaltrials.gov identifier: 02141282)

Current trends in the management of Richter's syndrome

Richter's syndrome (RS) is a life-threatening complication of chronic lymphocytic leukemia (CLL). While previous research has increased our knowledge on the distinct evolutionary patterns of RS and provided a deeper understanding of the risk factors and molecular events predisposing to transformation, there remain few targetable aberrations and treatment is largely ineffective. The ability to obtain deeper remissions, without selecting for deletion 17p, by using novel B-cell receptor (BCR) antagonists and bcl2 inhibition might lead to a decrease in the incidence of RS, but these agents have done little to significantly change outcomes when incorporated into treatment regimens for RS. In this review we highlight the current landscape of molecular lesions specific to RS, review the data on historical treatment options, and look to the horizon for potential opportunities in the future.

Real-world testing and treatment patterns in chronic lymphocytic leukemia: A SEER patterns of care analysis

BACKGROUND

Laboratory testing and treatments for chronic lymphocytic leukemia (CLL) have changed dramatically within the last decade. The authors evaluated changes in patterns of real-world testing and treatment over time by comparing 2 population-based cohorts.

METHODS

The National Cancer Institute-sponsored Patterns of Care study was conducted among patients with CLL who were sampled from 14 Surveillance, Epidemiology, and End Results (SEER) program registries. Demographics, testing, and treatment data were abstracted from medical records within 24 months of diagnosis.

RESULTS

A total of 1008 patients diagnosed in 2008 and 1367 patients diagnosed in 2014 were included. There was a significant increase in fluorescence in situ hybridization (FISH) testing, immunoglobulin heavy-chain variable region gene (IgVH ) mutation analyses, and lymph node biopsies between 2008 and 2014. FISH testing was performed in the majority of, but not all, treated patients (53% in 2008, which increased to 62% in 2014). Some differences in the receipt of FISH testing by age and insurance status were observed over time (older patients and Medicare patients without private insurance were less likely to be tested in 2014). There were contrasting testing patterns noted by practice type and year, with nonteaching hospitals more likely to perform bone marrow biopsies in 2008, and teaching hospitals more likely to perform FISH and IgVH testing in 2014. There also were differences in treatments over time, with the use of bendamustine and rituximab being more common in 2014, at the expense of fludarabine, cyclophosphamide, and rituximab.

CONCLUSIONS

There have been rapidly changing practices in the testing and treatment patterns of patients with CLL within the last decade.

Richter Syndrome Presenting With Colon Localization

A 75-year-old man, who had been diagnosed with small lymphocytic lymphoma with cervical localization, underwent F-FDG PET/CT with iodinated contrast medium due to the appearance of cervical swelling suspected of illness relapse. PET/CT revealed intense F-FDG uptake in multiple cervical and subdiaphragmatic lymph nodes and in the left parotid. Moreover, diffuse uptake and wall thickening of the colon were evident; endoscopy with biopsy revealed a diffuse large B-cell lymphoma. Transformation into a more aggressive lymphoma occurs in 2% to 8% of small lymphocytic lymphoma, the so-called Richter syndrome. Extranodal localization in the sigmoid colon is an extremely rare site for transformed lymphoma.

Richter transformation in the era of novel agents

Recent approvals of several oral targeted agents have revolutionized chronic lymphocytic leukemia (CLL) therapy. However, CLL patients continue to progress; particularly, 4% to 20% of previously treated CLL patients undergo transformation into high-grade lymphoma. Richter transformation is defined as a transformation of CLL into aggressive lymphoma, most commonly diffuse large B-cell lymphoma. These patients typically have poor response to traditional chemotherapy used to treat de novo diffuse large B-cell lymphoma and similar or shorter overall survival (median 3-11 months) in the era of novel agents. Here, I review the contemporary literature on Richter transformation, particularly in the context of novel agents used in CLL, and discuss the management approach for these patients.

The involvement of microRNA in the pathogenesis of Richter syndrome

Richter syndrome is the name given to the transformation of the most frequent type of leukemia, chronic lymphocytic leukemia, into an aggressive lymphoma. Patients with Richter syndrome have limited response to therapies and dismal survival. The underlying mechanisms of transformation are insufficiently understood and there is a major lack of knowledge regarding the roles of microRNA that have already proven to be causative for most cases of chronic lymphocytic leukemia. Here, by using four types of genomic platforms and independent sets of patients from three institutions, we identified microRNA involved in the transformation of chronic lymphocytic leukemia to Richter syndrome. The expression signature is composed of miR-21, miR-150, miR-146b and miR-181b, with confirmed targets significantly enriched in pathways involved in cancer, immunity and inflammation. In addition, we demonstrated that genomic alterations may account for microRNA deregulation in a subset of cases of Richter syndrome. Furthermore, network analysis showed that Richter transformation leads to a complete rearrangement, resulting in a highly connected microRNA network. Functionally, ectopic overexpression of miR-21 increased proliferation of malignant B cells in multiple assays, while miR-150 and miR-26a were downregulated in a chronic lymphocytic leukemia xenogeneic mouse transplantation model. Together, our results suggest that Richter transformation is associated with significant expression and genomic loci alterations of microRNA involved in both malignancy and immunity.

Clinical Impact of the 2016 Update to the WHO Lymphoma Classification

OPINION STATEMENT

The 2016 revision of the WHO classification of lymphoid neoplasms includes new entities along with a clearer definition of provisional and definitive subtypes based on better understanding of the molecular drivers of lymphomas. These changes impact current treatment paradigms and provide a framework for future clinical trials. Additionally, this update recognizes several premalignant or predominantly indolent entities and underscores the importance of avoiding unnecessarily aggressive treatment in the latter subsets.

Chronic lymphocytic leukemia with proliferation centers in bone marrow is associated with younger age at initial presentation, complex karyotype, and TP53 disruption

The presence of expanded proliferation centers (PCs) in lymph nodes involved by chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma has been associated with adverse clinical outcomes, but the frequency and significance of PCs in bone marrow (BM) remain unclear. The study group included 36 patients with BM involvement by CLL in which PCs were present. We compared this group with 110 randomly selected BM samples involved by CLL without morphologically discernable PCs. Patients with PCs in BM were younger (median age, 53 years [range,18-71 years] versus 58 years [range, 31-82 years]; P = .007), more frequently experienced B symptoms (27.8% versus 8.2%, P = .0076), more often had Rai stage IV disease (30.6% versus 17.3%, P = .02) and higher serum lactate dehydrogenase (P = .0037) and β₂-microglobulin (P = .0001) levels, and lower hemoglobin (P = .026) and platelet counts (P = .0422). TP53 alterations were more common in patients with PCs in BM (45.4% versus 18.7%; P = .0049), as was a complex karyotype (26.4% versus 9%; P = .019). There were no significant differences in the frequency of ZAP70 or CD38 positivity or IGHV mutation status. The median time to first treatment was shorter in patients with PCs in BM (7 months versus 19 months, P = .047), and the frequency of Richter syndrome was higher (14% versus 4%, P = .041). Patients with PCs in BM had significantly shorter overall survival compared with the control group (median, 249.3 months versus undefined; P = .0241). These data suggest that identification of PCs in BM samples involved by CLL is associated with adverse prognostic features.

Metabolic Tumor Volume Metrics in Lymphoma

Although visual assessment using the Deauville criteria is strongly recommended by guidelines for treatment response monitoring in all FDG-avid lymphoma histologies, the high rate of false-positives and concerns about interobserver variability have motivated the development of quantitative tools to facilitate objective measurement of tumor response in both routine and clinical trial settings. Imaging studies using functional quantitative measures play a significant role in profiling oncologic processes. These quantitative metrics allow for objective end points in multicenter clinical trials. However, the standardization of imaging procedures including image acquisition parameters, reconstruction and analytic measures, and validation of these methods are essential to enable an individualized treatment approach. A robust quality control program associated with the inclusion of proper scanner calibration, cross-calibration with dose calibrators and across other scanners is required for accurate quantitative measurements. In this section, we will review the technical and methodological considerations related to PET-derived quantitative metrics and the relevant published data to emphasize the potential value of these metrics in the prediction of patient prognosis in lymphoma.

Biology and treatment of Richter syndrome

Richter syndrome (RS) is the development of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL). Two pathologic variants of RS are recognized: namely, the diffuse large B-cell lymphoma (DLBCL) variant and the rare Hodgkin lymphoma (HL) variant. Histologic documentation is mandatory to diagnose RS. The clinical suspicion of RS should be based on clinical signs and symptoms. Differential diagnosis between CLL progression and RS and choice of the biopsy site may take advantage of positron emission tomography/computed tomography. Molecular lesions of regulators of proliferation (CDKN2A, NOTCH1, MYC) and apoptosis (TP53) overall associate with ∼90% of DLBCL-type RS, whereas the biology of the HL-type RS is largely unknown. The prognosis of the DLBCL-type RS is unfavorable; the outcome of HL-type RS appears to be better. The most important RS prognostic factor is the clonal relationship between the CLL and the aggressive lymphoma clones, with clonally unrelated RS having a better prognosis. Rituximab-containing combination chemotherapy for DLBCL is the most widely used treatment in DLBCL-type RS. Fit patients who respond to induction therapy should be offered stem cell transplantation (SCT) to prolong survival. Adriamycin, bleomycin, vinblastine, and dacarbazine is the preferred regimen for the HL-type RS, and SCT consolidation is less used in this condition.

Chronic Lymphocytic Leukemia: Diagnosis and Treatment

The complexity of the treatment of patients with chronic lymphocytic leukemia has increased substantially over the past several years as a consequence of the advent of novel biological agents such as ibrutinib, idelalisib, and venetoclax, as well as increasingly potent anti-CD20 monoclonal antibodies. In addition, the identification of molecular predictive markers and the introduction of more sensitive and sophisticated techniques to assess minimal residual disease have allowed optimization of the use of chemoimmunotherapy and targeted therapies and may become standard of care in the future. This review summarizes the diagnosis, prognostication, and treatment of patients with chronic lymphocytic leukemia with emphasis on new prognostic and predictive factors and novel treatment strategies.

Review of targeted therapy in chronic lymphocytic leukemia: what a radiologist needs to know about CT interpretation

The last 5 years have been marked by profound innovation in the targeted treatment of chronic lymphocytic leukemia (CLL) and indolent lymphomas. Using CLL as a case study, we present a timeline and overview of the current treatment landscape for the radiologist, including an overview of clinical and radiological features of CLL, discussion of the targeted agents themselves, and the role of imaging in response and toxicity assessment. The goal is to familiarize the radiologist with multiple Food and Drug Administration (FDA)-approved targeted agents used in this setting and associated adverse events which are commonly observed in this patient population.

Identification of a structurally novel BTK mutation that drives ibrutinib resistance in CLL

Ibrutinib (ibr), a first-in-class Bruton tyrosine kinase (BTK) inhibitor, has demonstrated high response rates in both relapsed/refractory and treatment naïve chronic lymphocytic leukemia (CLL). However, about 25% of patients discontinue ibrutinib therapy at a median follow-up of 20 months and many patients discontinue the treatment due to leukemia progression or Richter transformation. Mutations affecting the C481 residue of BTK disrupt ibrutinib binding and have been characterized by us and others as the most common mechanism of ibrutinib resistance. Thus far, all described BTK mutations are located in its kinase domain and mutations outside this domain have never been described. Herein, we report a patient whose CLL progressed, was salvaged with ibrutinib and then relapsed. Serial analysis of samples throughout patient's clinical course identified a structurally novel mutation (BTK^T316A) in the SH2 domain, but not kinase domain, of Bruton tyrosine kinase which was associated with disease relapse. Functionally, cells carrying BTK^T316A show resistance to ibrutinib at both cellular and molecular levels to a similar extent as BTK^C481S. Our study lends further insight into the diverse mechanisms of ibrutinib resistance that has important implications for the development of next-generation BTK inhibitors as well as mutation detection in relapsed patients.

B-cell lymphomas with discordance between pathological features and clinical behavior

B-cell lymphomas encompass a large number of disease entities clinically ranging from indolent to aggressive. The defining pathological features usually predict clinical course, with small and large B-cell lymphomas correlating to low-grade vs high-grade features, but discordant situations may be encountered. Two sessions of the workshop of the XVIII meeting of the European Association for Haematopathology (EAHP) held in Basel in 2016 addressed this topic. One session illustrated various facets of "aggressiveness" in indolent lymphomas, either peculiar clinical manifestations, cytological variants, or unusual genetic features, as well as several examples of progression or transformation to a more aggressive disease. Another session exemplified large B-cell lymphomas with unexpected indolent behavior including cases arising in well-defined body compartments or in sanctuary sites. This paper describes the features of the cases presented in both groups, highlights the most salient points of discussion raised by the submitters and the panel, and summarizes current knowledge and recommendations relevant to diagnostic pathology practice.

Factors predicting survival in chronic lymphocytic leukemia patients developing Richter syndrome transformation into Hodgkin lymphoma

We hereby report the clinical and biologic features of 33 of 4680 (0.7%) patients with chronic lymphocytic leukemia (CLL), managed at 10 Italian centers, who developed Hodgkin lymphoma (HL), a rare variant of Richter syndrome. The median age at CLL and at HL diagnosis were 61 years (range 41-80) and 70 years (range 46-82), respectively, with a median interval from CLL to the diagnosis of HL of 90 months (range 0-258). In 3 cases, CLL and HL were diagnosed simultaneously. Hl was characterized by advanced stage in 79% of cases, International Prognostic Score (IPS) ≥4 in 50%, extranodal involvement in 39%, B symptoms in 70%. Prior treatment for CLL had been received by 82% of patients and included fludarabine in 67%. Coexistence of CLL and HL was detected in the same bioptic tissue in 87% of cases. The most common administered treatment was the ABVD regimen given to 22 patients (66.6%). The complete response (CR) rate after ABVD was 68%, and was influenced by the IPS (P = .03) and interval from the last CLL treatment (P = .057). Survival from HL was also influenced by the IPS (P = .006) and time from the last CLL treatment (P = .047). The achievement of CR with ABVD was the only significant and independent factor predicting survival (P = .037). Taken together, our results show that the IPS and the interval from the prior CLL treatment influence the likelihood of achieving CR after ABVD, which is the most important factor predicting survival of patients with CLL developing HL.

Diffuse Large B-Cell Lymphoma in the Era of Precision Oncology: How Imaging Is Helpful

Diffuse large B cell lymphoma (DLBCL) is the most common histological subtype of Non-Hodgkin's lymphoma. As treatments continues to evolve, so do imaging strategies, and positron emission tomography (PET) has emerged as the most important imaging tool to guide oncologists in the diagnosis, staging, response assessment, relapse/recurrence detection,and therapeutic decision making of DLBCL. Other imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, and conventional radiography are also used in the evaluation of lymphoma. MRI is useful for nervous system and musculoskeletal system involvement and is emerging as a radiation free alternative to PET/CT. This article provides a comprehensive review of both the functional and morphological imaging modalities, available in the management of DLBCL.

Richter Syndrome in Chronic Lymphocytic Leukemia

The term Richter syndrome (RS) indicates the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma. RS is a rare complication with an aggressive clinical course, bearing an unfavorable prognosis. In the majority of cases, CLL transforms into RS as diffuse large B cell lymphoma (DLBCL), and a clonal relation between the two processes can be found. However, clonally unrelated RS can occur and transformations to other histologies beside DLBCL have been described. Recent data have shed some light on genetic characteristics that can influence and drive the transformation from CLL to RS. This molecular information has not been translated yet into significant treatment advances, and currently the therapy regimens for RS continue to rely on intensive chemotherapy combinations followed by stem cell transplant in suitable candidates. Based on the rapid pace of discoveries in the field of hematological malignancies and on the recent revolution in the therapeutic landscape for CLL and B cell lymphomas, new therapeutic options for RS might be available in the upcoming years.

Histologic transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma

Although generally considered a clinically indolent neoplasm, CLL/SLL may undergo transformation to a clinically aggressive lymphoma. The most common form of transformation, to DLBCL, is also known as Richter syndrome. Transformation determines the course of the disease and is associated with unfavorable patient outcome. Precise detection of transformation and identification of predictive biomarkers and specific molecular pathways implicated in the pathobiology of transformation in CLL/SLL will enable personalized therapeutic approach and provide potential avenues for improving the clinical outcome of patients. In this review, we present an overview of the pathologic features, risk factors, and pathogenic mechanisms of CLL/SLL transformation. Am. J. Hematol. 91:1036-1043, 2016. © 2016 Wiley Periodicals, Inc.

NCRI phase II study of CHOP in combination with ofatumumab in induction and maintenance in newly diagnosed Richter syndrome

Richter syndrome (RS) is associated with chemotherapy resistance and a poor historical median overall survival (OS) of 8-10 months. We conducted a phase II trial of standard CHOP-21 (cyclophosphamide, doxorubicin, vincristine, prednisolone every 21 d) with ofatumumab induction (Cycle 1: 300 mg day 1, 1000 mg day 8, 1000 mg day 15; Cycles 2-6: 1000 mg day 1) (CHOP-O) followed by 12 months ofatumumab maintenance (1000 mg given 8-weekly for up to six cycles). Forty-three patients were recruited of whom 37 were evaluable. Seventy-three per cent were aged >60 years. Over half of the patients received a fludarabine and cyclophosphamide-based regimen as prior CLL treatment. The overall response rate was 46% (complete response 27%, partial response 19%) at six cycles. The median progression-free survival was 6·2 months (95% confidence interval [CI] 4·9-14·0 months) and median OS was 11·4 months (95% CI 6·4-25·6 months). Treatment-naïve and TP53-intact patients had improved outcomes. Fifteen episodes of neutropenic fever and 46 non-neutropenic infections were observed. There were no treatment-related deaths. Seven patients received platinum-containing salvage at progression, with only one patient obtaining an adequate response to proceed to allogeneic transplantation. CHOP-O with ofatumumab maintenance provides minimal benefit beyond CHOP plus rutuximab. Standard immunochemotherapy for RS remains wholly inadequate for unselected RS. Multinational trials incorporating novel agents are urgently needed.

Richter's Transformation in the Era of Kinase Inhibitor Therapy: A Review

Richter's transformation (RT) is the transformation of chronic lymphocytic leukemia (CLL) into rapidly progressive B-cell lymphoma. This disease has long been recognized as a difficult-to-treat illness with poor survival outcomes. Although the incidence of RT has been well documented in previous studies, less is understood in the era of novel therapeutics, such as kinase inhibitors (KIs). The present review discusses the current risk factors, incidence, and outcomes of patients with RT in the modern era of KI therapy. Although the outcomes remain poor for RT patients after KI therapy, the most up-to-date studies have shown no increased incidence of RT in this patient population. Additionally, the present review reports the outcomes from the most recent data on novel therapies under investigation for patients with RT.

FDG-PET imaging in hematological malignancies

The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques.

Personalized Management Approaches in Lymphoma: Utility of Fluorodeoxyglucose-PET Imaging

PET/computed tomography (CT) imaging has gained a prominent role in the diagnosis and staging of malignancies. In lymphoma the role of PET/CT imaging continues to evolve as the understanding of its use in prognostication and response assessment improves. Currently, many groups are studying the potential function of PET/CT imaging in helping to direct management decisions for treating clinicians. This article summarizes the most up-to-date literature surrounding the topic of PET/CT-adaptive treatment of different lymphoma subjects. Although more studies are necessary to solidify the role of PET/CT, it is clear that this imaging modality holds much promise for the development of response-adaptive treatment algorithms in the future.

High-grade Transformation of Low-grade B-cell Lymphoma: Pathology and Molecular Pathogenesis

Patients with low-grade (clinically indolent) lymphomas are at risk to undergo transformation to high-grade (clinically aggressive) lymphoma, although transformation only occurs in a subset of patients. When transformation occurs it is a critical event that determines the course of disease and is associated with unfavorable patient outcomes. Accurate detection of transformation, predictive biomarkers, and identification of specific molecular pathways implicated in the pathobiology of transformation will facilitate personalized therapeutic approaches and underpin advances in clinical outcomes. In this article, we present an update of the clinical and pathologic diagnostic criteria for low-grade B-cell lymphoma transformation and discuss the molecular alterations involved in the pathogenesis of this biological phenomenon.

The 2016 revision of the World Health Organization classification of lymphoid neoplasms

A revision of the nearly 8-year-old World Health Organization classification of the lymphoid neoplasms and the accompanying monograph is being published. It reflects a consensus among hematopathologists, geneticists, and clinicians regarding both updates to current entities as well as the addition of a limited number of new provisional entities. The revision clarifies the diagnosis and management of lesions at the very early stages of lymphomagenesis, refines the diagnostic criteria for some entities, details the expanding genetic/molecular landscape of numerous lymphoid neoplasms and their clinical correlates, and refers to investigations leading to more targeted therapeutic strategies. The major changes are reviewed with an emphasis on the most important advances in our understanding that impact our diagnostic approach, clinical expectations, and therapeutic strategies for the lymphoid neoplasms.