Classifying B-cell non-Hodgkin lymphoma by using MIB-1 proliferative index in fine-needle aspirates

Head and neck follicular lymphoma with marginal zone differentiation and BCL2 translocation t(14;18) in both nodular and extranodular sites: a case report with mini-review

OBJECTIVE

Head and neck follicular lymphoma (FL) with marginal zone (MZ) differentiation is a rare high-risk B-cell composite variant that has been reported in nodular but not extranodular sites in the parotid glands. Here we summarize the literature on FL with MZ differentiation in head and neck nodular sites and describe a rare case of extranodular FL with MZ differentiation in the parotid gland.

STUDY DESIGN

We examined both the germinal center and MZ components of the parotid and bone-marrow biopsies of a 65-year-old female histologically, immunohistochemically, and molecularly to identify B-cell, germinal center, and follicular dendritic cell markers.

RESULTS

The immunohistochemical and molecular analysis provided evidence that the FL and the MZ components derived from the same B-cell clone with a similar BCL2/IGH t(14;18) translocation site. The differentiated cells in the MZ did not express germinal center markers BCL6 and CD10. Both the parotid and bone-marrow proliferative B cells showed BCL6, CD2O, and CD79a positivity.

CONCLUSIONS

Head and neck FL with MZ differentiation can develop in both nodular and extranodular sites and is characterized by BCL2 translocation t(14;18). Although the mechanism of MZ differentiation is unclear, the characterization of this rare histopathologic phenomenon might be clinically important.

Multicolor flow cytometric assessment of Ki67 expression and its diagnostic value in mature B-cell neoplasms

Background

There is no unified standard data about the sensitivity and specificity regarding flow cytometry analysis of Ki67 expression during lymphoma diagnoses.

Objective

This evaluated the efficacy of multicolor flow cytometry (MFC) in an estimate of the proliferative activity of B-cell non-Hodgkin lymphoma by comparing the expression of Ki67 using MFC and immunohistochemicals (IHC).

Method

A total of 559 patients with non-Hodgkin B-cell lymphoma were immunophenotyped using sensitive MFC, of which 517 were newly diagnosed and 42 were transformed lymphomas. Test samples include peripheral blood, bone marrow, various body fluids, and tissues. Through MFC multi-marker accurate gating, abnormal mature B lymphocytes with restricted expression of the light chain were screened. Ki67 was added to determine the proliferation index; the positive rate of Ki67 in tumor B cells was evaluated by cell grouping and internal control. For tissue specimens, MFC and IHC analyses were performed simultaneously to assess the Ki67 proliferation index.

Results

The positive rate of Ki67 by MFC was correlated with the subtype and aggressiveness of B-cell lymphoma. Ki67 could distinguish indolent lymphomas from aggressive subtypes with a cut-off value of 21.25%, and differentiate transformation from indolent lymphoma with a cut-off value of 7.65%. The expression of Ki67 by MFC (regardless of the type of samples)was highly agreement with the Ki67 proliferative index of tissue samples assessed by pathologic immunohistochemistry. MFC showed a fairly constant negative bias in evaluating tissue or bone marrow samples, compared with IHC.

Conclusions

Ki67 is a valuable flow marker that can distinguish between indolent and aggressive types of lymphoma and assess whether indolent lymphomas are transformed. Using MFC to evaluate the positive rate of Ki67 is important in clinical settings. MFC has unique advantages in judging the aggressiveness of lymphoma in samples of bone marrow, peripheral blood, pleural and ascites, and cerebrospinal fluid. This is particularly important when tissue samples cannot be obtained, making it an important supplement for pathologic examination.

Diffuse Large B-cell Lymphoma Presenting as a Primary Pleural Mass: A Case Report and Literature Review

Primary pleural lymphoma is a rare type of lymphoma that accounts for only ​​0.3% of all non-Hodgkin's lymphomas. The rarity and nonspecific clinical presentation of primary pleural lymphomas pose a diagnostic challenge for clinicians. We present an atypical case of primary pleural lymphoma in an elderly patient without any associated pleuro-pulmonary disease, immunosuppression, or history of lymphoma. To our knowledge, this is one of the first described cases of a primary pleural lymphoma with such a presentation.

Correlation of 18-fluorodeoxyglucose PET/computed tomography parameters and clinical features to predict outcome for diffuse large B-cell lymphoma

PURPOSE

To determine if the correlation between different metabolic parameters along with clinical features can create an improved model of prognostication for diffuse large B-cell lymphoma (DLBCL) patients.

METHODS

We retrospectively evaluated 89 patients with DLBCL. All patients had a baseline and an interim 18F-FDG PET/CT. Seventy-nine also had an end-of-treatment PET/CT (EOT-PET). For each scan, we collected standardized uptake value (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUVmaxsum, SUVmeansum, MTVsum, and TLGsum. These metabolic parameters were combined with clinical features in order to identify a new prognostic model. The predictive value of interim PET and EOT-PET using Deauville score was also determined.

RESULTS

Baseline SUVmaxsum and SUVmeansum were significantly correlated to overall survival (OS) (P value = 0.012 and 0.011, respectively). The percentage change of MTV and TLG sum from baseline to EOT was predictive of progression-free survival (PFS) (P value = 0.003 and 0.022, respectively). The combination of either Deauville score at the EOT and SUVmaxsum at baseline significantly predicted OS (P value <0.001); Eastern Cooperative Oncology Group performance status, presence of extranodal disease and percentage change of MTVsum from baseline to EOT were significant predictors of PFS (P value = 0.001).

CONCLUSIONS

SUVmaxsum and SUVmeansum at baseline and percentage change in MTV and TLG sum from baseline to EOT are predictors of outcome in DLBCL patients. These metabolic parameters combined to Deauville score and some clinical features could be used together to stratify patients.

A Clinically Applicable Approach to the Classification of B-Cell Non-Hodgkin Lymphomas with Flow Cytometry and Machine Learning

The immunophenotype is a key element to classify B-cell Non-Hodgkin Lymphomas (B-NHL); while it is routinely obtained through immunohistochemistry, the use of flow cytometry (FC) could bear several advantages. However, few FC laboratories can rely on a long-standing practical experience, and the literature in support is still limited; as a result, the use of FC is generally restricted to the analysis of lymphomas with bone marrow or peripheral blood involvement. In this work, we applied machine learning to our database of 1465 B-NHL samples from different sources, building four artificial predictive systems which could classify B-NHL in up to nine of the most common clinico-pathological entities. Our best model shows an overall accuracy of 92.68%, a mean sensitivity of 88.54% and a mean specificity of 98.77%. Beyond the clinical applicability, our models demonstrate (i) the strong discriminatory power of MIB1 and Bcl2, whose integration in the predictive model significantly increased the performance of the algorithm; (ii) the potential usefulness of some non-canonical markers in categorizing B-NHL; and (iii) that FC markers should not be described as strictly positive or negative according to fixed thresholds, but they rather correlate with different B-NHL depending on their level of expression.

Cytological preparations for molecular analysis: A review of technical procedures, advantages and limitations for referring samples for testing

Minimally invasive procedures such as endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) must yield not only good quality and quantity of material for morphological assessment, but also an adequate sample for analysis of molecular markers to guide patients to appropriate targeted therapies. In this context, cytopathologists worldwide should be familiar with minimum requirements for refereeing cytological samples for testing. The present manuscript is a review with comprehensive description of the content of the workshop entitled Cytological preparations for molecular analysis: pre-analytical issues for EBUS TBNA, presented at the 40th European Congress of Cytopathology in Liverpool, UK. The present review emphasises the advantages and limitations of different types of cytology substrates used for molecular analysis such as archival smears, liquid-based preparations, archival cytospin preparations and FTA (Flinders Technology Associates) cards, as well as their technical requirements/features. These various types of cytological specimens can be successfully used for an extensive array of molecular studies, but the quality and quantity of extracted nucleic acids rely directly on adequate pre-analytical assessment of those samples. In this setting, cytopathologists must not only be familiar with the different types of specimens and associated technical procedures, but also correctly handle the material provided by minimally invasive procedures, ensuring that there is sufficient amount of material for a precise diagnosis and correct management of the patient through personalised care.

Preanalytic specimen triage: Smears, cell blocks, cytospin preparations, transport media, and cytobanking

With increasing requests for the evaluation of prognostic and predictive molecular biomarkers, great attention must be paid to the preanalytical issues regarding sample quality and DNA/RNA yield from all different types of cytological preparations. The objectives of this review were: 1) to provide an update regarding the importance of specimen triage as well as specimen handling and collection; 2) to discuss the different cell preparations that can be used for molecular testing, their advantages and limitations; and 3) to highlight the strategies for biobanking cytology samples. Good-quality DNA/RNA can be harvested from fresh cells in cell suspensions, formalin-fixed paraffin-embedded cell blocks, archival stained smears, archival unstained cytospin preparations, liquid-based cytology slides, FTA cards, and cryopreserved cells. In contrast to formalin-fixed paraffin-embedded tissue specimens (small biopsies and surgical resections), the multitude of types of sample preparations as well as the diversity in sample collection and processing procedures make cytology an ideal specimen for most genomic platforms, with less DNA and RNA degradation and a purer sample, usually with a higher concentration of tumor cells. The broad incorporation of cytological specimens into clinical practice. A should increase the number of samples potentially available for molecular tests and avoid repeat invasive procedures for tissue procurement, thereby increasing patient safety. In this context, it is of utmost importance that cytopathologists become familiar with the variables that can affect test results and embrace the goal of excellence in sample quality. Cancer Cytopathol 2017;125(6 suppl):455-64. © 2017 American Cancer Society.

Cytologic perspectives on neoteric B-cell lymphoproliferative disorders

The 2008 World Health Organization (WHO) classification of hematopoietic and lymphoid tissues has been recently revised, and publication of the updated 2016 version is expected soon. Given that cytopathologists are often involved in the diagnosis of primary, recurrent, and transformed lymphoproliferative disorders, knowledge of updates to the WHO lymphoma classification, including terminology, pathogenesis, ancillary techniques, and targeted therapies is necessary. Herein, we reference the last decade of cytology specific literature for seven newer B-cell disorders and provide illustrative examples of each entity from our files.

Distribution of Ki67 proliferative indices among WHO subtypes of non-Hodgkin's lymphoma: association with other clinical parameters

BACKGROUND

Non-hodgkin lymphoma (NHL) is a diverse group of disease encompassing divergent tumor types with contrasting clinical behaviors. We aimed to evaluate the usefulness of Ki67 index in segregating indolent from aggressive NHL and its association with clinical parameters.

MATERIALS AND METHODS

During a study period of 4.5 years, a total of 215 cases of lymphomas were diagnosed among of which 172 cases were NHL. Ki67 immunohistochemical staining was performed by the DAKO envision method. Average proportion of tumor cells stained was calculated to determine the proliferative index.

RESULTS

The mean age at diagnosis was 46.2 years +19.8 (3-81) with a male to female ratio of 1.5:1. Mean Ki67 index for indolent NHL included 23% for small cell, 25% for mantle cell, 28.5% for marginal zone and 34.6% for follicular lymphoma. On the other hand, mean Ki67 index for aggressive lymphomas were 66.4%, 66.9%, 80.3%, 83.3% and 94.4% for diffuse large B cell, T cell (NOS), anaplastic large cell, lymphoblastic and burkitts lymphoma respectively. No significant correlation was found between Ki67 index and other clinical parameters like age and extra nodal involvement.

CONCLUSIONS

Ki67 index is a valuable IHC marker to distinguish indolent from aggressive lymphomas especially in small needle biopsies where exact typing may not be possible.

Flow cytometric evaluation of ki67 for the determination of malignancy grade in canine lymphoma

Ki67 is a nuclear antigen significantly correlated with degree of malignancy in human non-Hodgkin lymphomas. We wanted to assess the ability of flow cytometric evaluation of Ki67 index (Ki67I) in differentiating the grade of malignancy in canine lymphomas. Ki67I was determined on lymph node aspirates of 90 immunophenotyped lymphomas classified according to the updated Kiel classification: 80 high grade (HG, 62 B cell and 18 T cell) and 10 low grade (LG, 3 B cell and 7 T cell) lymphomas. HG lymphomas showed significantly higher Ki67I compared with LG lymphomas (P < 0.0001). A significant difference in HG lymphomas was detected between B- and T-immunophenotypes. Receiver operating characteristic (ROC) curve highlighted a high accuracy of Ki67I in recognizing HG lymphomas [area under the curve (AUC) = 99.4] and a cut-off value of 12.2% was established (sensitivity = 96.3% and specificity = 100%). Thus, we suggest the combination of Ki67I flow cytometric determination and immunophenotype as a reliable tool to classify canine lymphomas.

EZH2 and CD79B mutational status over time in B-cell non-Hodgkin lymphomas detected by high-throughput sequencing using minimal samples

BACKGROUND: Numerous genomic abnormalities in B-cell non-Hodgkin lymphomas (NHLs) have been revealed by novel high-throughput technologies, including recurrent mutations in EZH2 (enhancer of zeste homolog 2) and CD79B (B cell antigen receptor complex-associated protein beta chain) genes. This study sought to determine the evolution of the mutational status of EZH2 and CD79B over time in different samples from the same patient in a cohort of B-cell NHLs, through use of a customized multiplex mutation assay.

METHODS: DNA that was extracted from cytological material stored on FTA cards as well as from additional specimens, including archived frozen and formalin-fixed histological specimens, archived stained smears, and cytospin preparations, were submitted to a multiplex mutation assay specifically designed for the detection of point mutations involving EZH2 and CD79B, using MassARRAY spectrometry followed by Sanger sequencing.

RESULTS: All 121 samples from 80 B-cell NHL cases were successfully analyzed. Mutations in EZH2 (Y646) and CD79B (Y196) were detected in 13.2% and 8% of the samples, respectively, almost exclusively in follicular lymphomas and diffuse large B-cell lymphomas. In one-third of the positive cases, a wild type was detected in a different sample from the same patient during follow-up.

CONCLUSIONS: Testing multiple minimal tissue samples using a high-throughput multiplex platform exponentially increases tissue availability for molecular analysis and might facilitate future studies of tumor progression and the related molecular events. Mutational status of EZH2 and CD79B may vary in B-cell NHL samples over time and support the concept that individualized therapy should be based on molecular findings at the time of treatment, rather than on results obtained from previous specimens. Cancer (Cancer Cytopathol) 2013;121:377–386. © 2013 American Cancer Society.

Diagnosis of B-cell non-hodgkin lymphomas with small-/intermediate-sized cells in cytopathology

Fine needle sampling is a fast, safe, and potentially cost-effective method of obtaining tissue for cytomorphologic assessment aimed at both initial triage and, in some cases, complete diagnosis of patients that present clinically with lymphadenopathy. The cytologic diagnosis of B-cell non-Hodgkin lymphomas composed of small-/intermediate-sized cells, however, has been seen as an area of great difficulty even for experienced observers due to the morphologic overlap between lymphoma and reactive lymphadenopathies as well as between the lymphoma entities themselves. Although ancillary testing has improved diagnostic accuracy, the results from these tests must be interpreted within the morphological and clinical context to avoid misinterpretation. Importantly, the recognition of specific cytologic features is crucial in guiding the appropriate selection of ancillary tests which will either confirm or refute a tentative diagnosis. For these reasons, we here review the cytologic characteristics particular to five common B-cell non-Hodgkin lymphomas which typically cause the most diagnostic confusion based on cytological assessment alone: marginal zone lymphoma, follicular lymphoma, mantle cell lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, and lymphoplasmacytic lymphoma. We summarize the most pertinent cytomorphologic features for each entity as well as for reactive lymphoid hyperplasia, contrast them with each other to facilitate their recognition, and highlight common diagnostic pitfalls.

The use of FTA cards for preserving unfixed cytological material for high-throughput molecular analysis

BACKGROUND

Novel high-throughput molecular technologies have made the collection and storage of cells and small tissue specimens a critical issue. The FTA card provides an alternative to cryopreservation for biobanking fresh unfixed cells. The current study compared the quality and integrity of the DNA obtained from 2 types of FTA cards (Classic and Elute) using 2 different extraction protocols ("Classic" and "Elute") and assessed the feasibility of performing multiplex mutational screening using fine-needle aspiration (FNA) biopsy samples.

METHODS

Residual material from 42 FNA biopsies was collected in the cards (21 Classic and 21 Elute cards). DNA was extracted using the Classic protocol for Classic cards and both protocols for Elute cards. Polymerase chain reaction for p53 (1.5 kilobase) and CARD11 (500 base pair) was performed to assess DNA integrity.

RESULTS

Successful p53 amplification was achieved in 95.2% of the samples from the Classic cards and in 80.9% of the samples from the Elute cards using the Classic protocol and 28.5% using the Elute protocol (P = .001). All samples (both cards) could be amplified for CARD11. There was no significant difference in the DNA concentration or 260/280 purity ratio when the 2 types of cards were compared. Five samples were also successfully analyzed by multiplex MassARRAY spectrometry, with a mutation in KRAS found in 1 case.

CONCLUSIONS

High molecular weight DNA was extracted from the cards in sufficient amounts and quality to perform high-throughput multiplex mutation assays. The results of the current study also suggest that FTA Classic cards preserve better DNA integrity for molecular applications compared with the FTA Elute cards.

Case studies of elderly patients with non-Hodgkin's lymphoma

The treatment of patients with non- Hodgkin’s lymphoma (NHL) is often the treatment of elderly patients, as most patients are older than 65 years at diagnosis. These elderly patients present particular therapeutic challenges, because they may be more frail and at greater risk of treatment-related toxicity, especially anthracycline-related cardiotoxicity, than younger patients. The following two case studies illustrate the challenges and therapeutic decision-making in managing elderly patients with an aggressive and an indolent form of lymphoma.

Maximizing the yield of lymph node cytology: Lessons learned from rapid onsite evaluation of image- and endoscopic-guided biopsies of hilar and mediastinal lymph nodes

The evaluation of mediastinal and hilar lymph nodes for tissue diagnosis and staging of lung cancer is now commonly performed by minimally invasive, nonsurgical procedures such as computed tomography-guided fine-needle aspiration and endobronchial ultrasound-guided transbronchial needle aspiration. Ensuring that a sufficient quantity of cellular material has been acquired to enable multiple studies has become a priority issue in the era of personalized medicine, especially for patients with lung cancer, and this can be accomplished by rapid onsite evaluation (ROSE). This commentary focuses on the use of ROSE in guided procedures, especially for hilar and mediastinal lymph node aspirates, and describes an algorithm for handling these specimens.

Diagnosis and subclassification of lymphomas and non-neoplastic lesions involving mediastinal lymph nodes using endobronchial ultrasound-guided transbronchial needle aspiration

INTRODUCTION

The value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been established for staging mediastinal lymph nodes in lung carcinoma patients with radiologically enlarged lymph nodes, but its utility for evaluation of primary lymph node disorders is not well defined. The objective of this study was to evaluate the usefulness of EBUS-TBNA with on-site assessment and triage of sample for multiple ancillary techniques, for the diagnosis and subclassification of lymphomas and non-neoplastic lesions involving mediastinal lymph nodes.

METHODS

One hundred and twenty consecutive patients who underwent EBUS-TBNA between January 2008 and August 2009 were reviewed. The final cytological diagnosis was based on air-dried Romanowsky and alcohol-fixed Papanicolaou stained direct smears, immunohistochemistry, immunophenotyping, and fluorescence in situ hybridization (FISH).

RESULTS

A total of 38 cases were included in this study consisting of eight reactive lymphoid hyperplasia, 20 granulomatous lymphadenitis (17 non-necrotizing and 3 necrotizing granulomatous inflammations), 3 Hodgkin lymphomas and 7 non-Hodgkin lymphomas (1 small lymphocytic lymphoma (SLL), 1 SLL with scattered Reed-Sternberg cells, 1 marginal zone lymphoma, and 4 large B cell lymphomas). Cultures performed in 13 cases were negative for AFB and fungi. Immunophenotyping and immunohistochemistry for MIB1 in six cases, and FISH in five cases provided necessary information for subclassification.

CONCLUSIONS

EBUS-TBNA is a minimally invasive procedure which provides sufficient sample for definitive primary diagnosis and classification of malignant lymphoma and granulomatous inflammation in patients with mediastinal lymphadenopathy. Rapid on-site specimen assessment is invaluable for appropriate assignment of sample to ancillary studies.