Utility of Flow Cytometry Immunophenotyping in Fine-needle Aspirate Cytologic Diagnosis of Non-Hodgkin Lymphoma: A Series of 252 Cases and Review of the Literature

Enhancing lymphoma diagnosis on core needle biopsies: Integrating immunohistochemistry with flow cytometry

Image-guided core needle biopsies (IG-CNB) represent a minimally invasive approach for obtaining tissue in patients with lymphadenopathy and suspected lymphoma. Despite their utility, diagnostic challenges persist, with lower efficacy compared with excisional biopsies. Our study aimed to evaluate the potential utility of incorporation of flow cytometry (FC) alongside immunohistochemistry (IHC) when performing IG-CNB for suspected lymphoproliferative diseases. Analyzing 170 consecutive cases, guided by ultrasound (n = 94) or computer tomography (n = 76), we employed a diagnostic algorithm, already established in our laboratory practice, utilizing three antibody cocktail-equipped tubes tailored for defining lymphomas, particularly those of B-cell origin. FC expedited the diagnostic process, yielding presumptive results in 87.6% of cases within 48 h, with a positive predictive value of 98%. Addition of FC to routine IHC enhanced the diagnostic rate from 91.2% to 95.3%, reducing IG-CNB failure rate by 45%, from 8.8% to 4.7%. This enhancement was particularly notable for deep-seated sites and in the setting of suspected disease recurrences. Consequently, FC emerges as a valuable adjunctive tool, allowing for the improvement of diagnostic performance, with a particular focus on the ability to quantify the expression of surface markers for targeted therapies, and holding the potential to diminish the necessity for repeat excisional biopsies subsequent to IG-CNB procedures.

Imprint cytology: Invaluable technique to evaluate fresh specimens received in the pathology department for Lymphoma workup

At the time of intraoperative consultation, cytologic preparations including smears and imprints can be used in combination with frozen sections to increase diagnostic yield; however, these simple and rapid techniques are not adopted by all pathologists and their use varies considerably between institutions. In patients under investigation for suspected lymphoma, optimal triaging of tissue received fresh in pathology for lymphoma workup is paramount to maximize the odds of obtaining an accurate and clinically meaningful diagnosis and to avoid the need for additional procedures and delays in management, particularly in the current context in which core biopsies have become common practice as a first attempt to attain this goal. Imprint cytology is invaluable in this regard, also as these patients may not have a lymphoma but rather one of its clinical mimics. Herein, imprint cytology is used to approach fresh specimens received intraoperatively for lymphoma workup. More specifically, how these specimens are triaged for ancillary studies, such as flow cytometry, florescence in situ hybridization, or molecular analyses based on an interpretation of the touch imprints, is described. Detailed imprint cytological findings of typical benign and malignant lymphoid and nonlymphoid lesions are discussed and illustrated.

Diagnostic accuracy of fine-needle aspiration cytology for lymphoma: A systematic review and meta-analysis

BACKGROUND

Fine-needle aspiration cytology (FNAC) has become one of the most useful modalities for diagnosis and staging of lymphoma. However, diagnostic accuracy of this technique has been reported with varying results across several studies around the world. Hence, this meta-analysis was done to assess the accuracy of FNAC for lymphoma diagnosis.

METHODS

We conducted a systematic search for all studies reporting the diagnostic accuracy of FNAC for lymphoma in the databases of PubMed Central, MEDLINE, EMBASE, MEDLINE, SCOPUS and Cochrane library from inception till January 2021. Meta-analysis was performed using STATA software "midas" package.

RESULTS

Forty-seven studies with 7268 patients were included. The pooled sensitivity and specificity of FNAC for diagnosing lymphoma were 93% (95% CI, 90%-95%) and 97% (95% CI, 95%-98%), respectively. Likelihood ratio positive was 33.5 (95% CI, 18.5-60.7) and likelihood ratio negative was 0.07 (0.05-0.11) making the technique to occupy the left upper quadrant in LR scattergram indicating that FNAC can be used for confirmation and exclusion. There was significant heterogeneity with significant chi-square test and I² statistic >75%. There was significant publication bias as per Deek's test and funnel plot.

CONCLUSION

To summarize, our study found that FNAC has a vital role as a diagnostic tool for lymphoma with higher sensitivity and specificity. Further studies assessing the accuracy of FNAC on specific types of lymphoma is required.

Contribution of small tissue biopsy and flow cytometry to preoperative cytological categorization of salivary gland fine needle aspirates according to the Milan System: Single center experience on 287 cases

BACKGROUND

Milan system for reporting salivary gland cytopathology (MSRSGC) was proposed to provide a standardized reporting system for salivary gland fine needle aspiration biopsies. Modified Menghini type semi-automatic aspiration biopsy needles provide small tissue fragments (STFs), as well as cellular smears, and immunohistochemical and molecular studies can be performed using the STFs.

AIMS

We aimed to evaluate the contribution of STFs and ancillary techniques to pre-operative diagnosis of salivary gland lesions.

MATERIALS AND METHODS

In this study, smears of 287 cases with histopathological correlation were re-reviewed and assigned to one of the MSRSGC categories. In the second step, histopathological and immunohistochemical findings in STFs were evaluated together with cytological findings. Final diagnoses were obtained with the inclusion of flow cytometry (FC) results when available. Risk of malignancy (ROM) was calculated for each diagnostic category.

RESULTS

In the evaluation based on smears, a specific diagnosis could be obtained in 64.8% of the cases. ROMs were 0% for nondiagnostic (ND), 5.6% for non-neoplastic (NN), 55% for atypia of undetermined significance (AUS), 0.6% for benign neoplasm (BN), 27.8% for salivary gland neoplasm of uncertain malignant potential (SUMP), and 100% for suspicious for malignancy (SFM) and malignant (M) categories. With the addition of histopathological and immunohistochemical findings and FC results, a specific diagnosis could be obtained in 75.2% of the cases. ROMs were 0% for ND, 4.5% for NN, 53.8% for AUS, 0.6% for BN, 0% for SUMP, and 100% for SFM/M categories.

CONCLUSIONS

STFs contribute correct categorization of salivary gland lesions. The major contribution of ancillary methods is in the SUMP category.

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.

Value of multi-parameter flow cytometry immunophenotyping in T/NK-cell neoplasms in cytology specimens: A retrospective study in Chinese patients

BACKGROUND

Innate limitations of morphological diagnosis of T/NK-cell neoplasms mean that they can be misdiagnosed or missed, especially when mixed with a variety of benign and reactive conditions. The aim of this study was to investigate the application value of multiparameter flow cytometry immunophenotyping (MFCI) in screening and diagnosing T/NK-cell neoplasms with cytology specimens.

MATERIAL AND METHODS

The clinical and pathological characteristics of 1028 newly diagnosed cases from Fudan University Shanghai Cancer Center who provided a cytology specimen between June 2010 and January 2016 with correlated histology diagnosis and clinical confirmation were retrospectively reviewed. MFCI was used for screening, diagnosis and typing. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in diagnosis of T/NK-cell neoplasms were calculated.

RESULTS

There were 606 males and 422 females in 1028cases, with a mean age of 47.5 years (range 9-86 years). Specimens used for cytologic diagnosis included 996 FNAs, 2 US-FNAs, 13 EUS-FNAs and 17 effusions. Screening for types of lymphoma of MFCI, 139 (13.52 %) cases were T/NK cell lymphoma, 3 (0.29 %) cases were B cell lymphoma T-NHL and B-NHL coexist. A total of 146 suspected T/NK-cell neoplasms were screened out (sensitivity = 94.64 %, specificity = 95.63 % PPV = 72.60 %, NPV = 99.32 %) by MFCI, with 112 (76.71 %) histologically confirmed cases and 6 (4.11 %) false-negative cases identified (3 cases diagnosed as B-cell neoplasms and 1 case as T-cell neoplasm with B-cell neoplasm, which also were confirmed by gene rearrangement. 2 cases were suspicious T-cell-immunophenotypic abnormalities). When used at the diagnostic level, a total of 88 T/NK-cell neoplasms were identified (sensitivity = 68.75 %, specificity = 98.80 %, PPV = 87.50 %, NPV = 96.28 %) with 11 false-positive cases recognized, 9 of which showed typical immunophenotypic T-cell neoplasms features, and 2 exhibited aberrant T immunophenotype.

CONCLUSIONS

MFCI has high sensitivity and specificity in the screening and diagnosis of T/NK-cell neoplasms and may be useful as an alternative diagnosis method in cytology specimens.

Differential Diagnosis of Malignant Lymphadenopathy Using Flow Cytometry on Fine Needle Aspirate: Report on 269 Cases

Introduction: Fine needle aspiration (FNA) is frequently the first noninvasive test used for the diagnostic workup of lymphadenopathy. There have been many studies showing its usefulness, especially in conjunction with other techniques for the diagnosis of lymphoma, but it remains inferior to histological examination. The data regarding this subject have mostly been reported mostly from first-world countries, but are scarce for emerging economies. Thus, the current study assesses the agreement between fine needle aspiration flow cytometry (FNA FC) and histology in the aforementioned region. Material and Methods: We conducted a retrospective study including the FNA FC adenopathy diagnoses made between January 2011 and December 2016 at the Tygerberg Hospital, Cape Town, South Africa. Additional variables included were the histological diagnosis, sex and age of the included patients. Results: In the descriptive part of the current study, 269 FNA FC samples were included. The most frequent diagnoses made on these were represented by B-cell lymphoma, reactive adenopathy, no abnormality detected (NAD), and non-hematological malignancy. In the analytical part of the current study, there were 115 cases included that had both valid FNA FC and histological diagnoses. It could be observed that FNA FC can correctly diagnose B-cell lymphoma in most cases, but it is a poor diagnostic tool especially for Hodgkin lymphoma in this setting as only a four-color flow cytometer was available for diagnosis. Moreover, FNA FC diagnosis of reactive adenopathy and of no abnormalities detected was shown to frequently hide a malignant disease. Conclusion: In countries with scarce resources, FNA FC represents a useful diagnostic tool in the case of B-cell lymphoma, but may misdiagnose reactive adenopathy. Thus, FNA FC should be used in a case-specific manner, in addition to as a screening tool, with the knowledge that in cases with a high clinical suspicion of lymphoma, histological diagnosis is a necessity.

Feasibility of flow cytometric analysis of restricted light chain in endoscopic biopsy specimens from patients with gastrointestinal tract B cell lymphoma: a pilot study

OBJECTIVE

Gastrointestinal tract lymphomas are currently detected more frequently due to advances in endoscopic technology. The aim of this study was to assess the feasibility of flow cytometric analysis of restricted light chain in endoscopic biopsy specimens for the diagnosis of gastrointestinal tract B-cell lymphoma. We prepared viable cell suspensions from unfixed specimens obtained from 10 consecutive patients who had a previous histological diagnosis of gastrointestinal tract B-cell lymphoma. We performed immunophenotypic studies with multi-color flow cytometry and assessed clonality through examination of immunoglobulin light chain expression exclusively in a population identified by anti-CD45 or CD20 antibodies.

RESULTS

We could perform light chain expression analysis with 2 endoscopic biopsy specimens from all 10 patients with gastrointestinal tract B-cell lymphoma. We conclude that flow cytometric analysis of endoscopic biopsy specimens is feasible and thus likely useful for the diagnosis of gastrointestinal tract B-cell lymphoma in clinical settings. Trial registration UMIN Clinical Trials Registry, UMIN000027730. Registered 12 June 2017.

Development of transplantable B-cell lymphomas in the MHC-defined miniature swine model

Background

Establishment of transplantable tumors in clinically relevant large animals allows translational studies of novel cancer therapeutics.

Methods

Here we describe the establishment, characterization, and serial transplantation of a naturally occurring B-cell lymphoma derived from a unique, highly inbred sub-line of Massachusetts General Hospital (MGH) major histocompatibility complex (MHC)-defined miniature swine.

Results

The lymphoblastic cell line (LCL) originated from peripheral blood of a 2.5 year old female swine leukocyte antigen (SLA)^dd-inbred miniature swine breeder demonstrating clinical signs of malignancy. Flow cytometric phenotypic analysis of subclones derived from the original cell line revealed surface markers commonly expressed in a B-cell lineage neoplasm. A subclone of the original LCL was transplanted into mildly-conditioned histocompatible miniature swine and immunocompromised NOD.Cg-Prkdc^scidIl2rg^tm1Wjl/SzJ (NSG) mice. Tissue and blood samples harvested 2 weeks following subcutaneous and intravenous injection in a highly inbred SLA^dd pig were cultured for tumor growth and phenotypic analysis before serial transfer into NSG mice. Evidence of tumor growth in vivo was found in all tumor cell recipients. In vitro growth characteristics and surface phenotype were comparable between the original and serially transplanted tumor cell lines.

Conclusions

These results indicate the feasibility of developing a large-animal transplantable tumor model using cells derived from spontaneously occurring hematologic malignancies within the highly inbred miniature swine herd.

Usefulness of Bcl-2 Expression and the Expression of Cytoplasmic Immunoglobulin Light Chains in the Differentiation Between B-Cell Lymphoma and Reactive Lymphocytic Proliferations in FNA

Flow cytometry is helpful in differentiating between B-cell lymphoma (BCL) and reactive lymphocytic proliferation (RLP) in FNA biopsies. However; the presence of inconclusive surface immunoglobulin light chains (sIg LC) poses a problem. We investigated the usefulness of additional tests; namely Bcl-2 expression and expression of cytoplasmic Ig LC (cIg LC), mainly on samples with inconclusive sIg LC. Both tests were performed on 232 FNA samples from lymph nodes. Bcl-2 alone was determined qualitatively and quantitatively on 315 samples. The quantitative test was correctly positive in 76% of cases and falsely negative in 24%. The correctly positive results of the qualitative test were 11% points lower. cIg LC correctly identified 65% of BCL with dual positive sIg LC; 36% of BCL with difficult to interpret sIg LC and only 7% of BCL with negative sIg LC. The best results in differentiating between BCL and RLP were obtained when all three tests were used together. In samples with inconclusive sIg LC and additional monoclonal or polyclonal populations the κ:λ ratios did not differentiate between RLP and BCL. We propose that in case of inconclusive sIg LC Bcl-2 test is used first. The addition of cIg LC test is sensible only in cases with dual positive and difficult to interpret sIg LC.

Flow cytometry identification of nonhemopoietic neoplasms during routine immunophenotyping

INTRODUCTION

Nonhemopoietic neoplasms (NHNs) may be encountered during routine flow cytometry (FC) immunophenotyping. The clue of their presence mainly relies on detection of CD45-negative (CD45-) cells with altered scatter parameters.

METHODS

In this study, we evaluated a monoclonal antibody combination conceived to characterize the CD45- population by FC, suspected of belonging to NHNs, when present. The panel included CD45 for leucocytes identification, CD326 (clones BerEP4 and HEA-125) to mark epithelial cells, CD33 to identify myeloid cells, CD138 to trace plasma cells and CD56 useful in the identification of neuroendocrine tumours. 7AAD vital dye was used to gate out dead cells. Results were correlated with cytomorphology and confirmed by histological data, if available.

RESULTS

Among 9422 specimens submitted for routine FC investigation, 47 samples that included fine-needle aspirates, bone marrow aspirates, tissue biopsies and body fluids had a detectable CD45- population and a sufficient cell amount to be further investigated. FC revealed the presence of CD326-positive epithelial cells in 38 specimens; altered scatter parameters and variable reactivity to the other antigens tested allowed to suspect NHNs in the remaining nine samples. The presence of NHNs was confirmed in all cases by morphology.

CONCLUSIONS

The current results show that when CD45- cells with altered scatter parameters were detected, cytometrists involved in leukaemia/lymphoma diagnosis may require further FC investigations to rapidly identify NHNs in different specimens, thus reducing the time of the immunohistochemical diagnostic workup to reach a final diagnosis.

Utility of Flow Cytometry in Diagnosing Hematologic Malignancy in Tonsillar Tissue

OBJECTIVE

Tonsil surgical biopsy or excision is a very common procedure. However, there exist no consensus guidelines for the pathologic handling of tonsil specimens; gross and/or microscopic evaluation may be used. Diagnosis of tonsillar hematologic malignancy requires histology, immunohistochemistry and/or flow cytometry. Data regarding the utility of flow cytometry in tonsillar tissues are limited. We assessed our experience with flow cytometry for tonsil diagnosis with regard to accuracy and use patterns at a tertiary academic medical center.

METHODS

We retrospectively analyzed all surgically biopsied or excised tonsil specimens that underwent flow cytometry evaluation from August 2011 to March 2014. Patient clinical information, intraoperative frozen section, histology, immunohistochemistry, and flow cytometry diagnoses were recorded.

RESULTS

The study included 154 tonsil specimens from 89 females and 65 males. Patients averaged 27.4 years old (range 2-87 years); 73 were pediatric. Both histology and flow cytometry were benign for 148 patients (96.1%). Hematolymphoid malignancy was diagnosed in 6 adults by histology/immunohistochemistry: diffuse large B-cell lymphoma (2), small B-cell lymphoma (2), concomitant follicular lymphoma and histiocytic sarcoma (1), and extraosseous plasmacytoma (1). Flow cytometry identified abnormal populations in 5 of 6 cases, and detected clonal populations in 2 reactive follicular hyperplasia cases.

CONCLUSION

Tonsillar hematolymphoid malignancy is uncommon, and flow cytometry was less accurate than histology/immunohistochemistry for its diagnosis. Despite the rarity of tonsillar lymphoma in children, nearly half of study patients were pediatric. Intraoperative frozen section diagnosis showed excellent sensitivity for malignancy, and could be used to effectively triage cases for flow cytometry evaluation.

Image-guided fine-needle aspiration cytology and flow cytometry phenotyping of neck lymphadenopathy for the diagnosis of recurrent lymphoma

OBJECTIVE

In patients with a history of lymphoma, each lymphadenopathy should be carefully evaluated. The aims of this study were to evaluate (i) the usefulness of high-resolution ultrasonography (US), US-guided fine-needle aspiration cytology (FNAC) and flow cytometry phenotyping (FCP) together in the diagnosis of recurrent lymphoma and (ii) whether these tools were independent predictors of correct results.

DESIGN

Retrospective cohort study with stepwise forward logistic regression analysis of results.

SETTING

Tertiary referral centre.

PARTICIPANTS

A total of 151 patients with a history of lymphoma who developed a cervical mass during follow-up.

METHODS

On neck US, a lymphadenopathy was shown in 129 (85.4%) patients (median age 57 years, range 18-78 years), and US-guided FNAC combined with FCP were immediately performed. All patients had surgical excision and subsequent histological examination of the enlarged node(s), to establish lymphoma subclassification.

RESULTS

Final histology confirmed recurrence in 82 (63.6%) patients. According to the logistic regression analysis, FNAC and FCP were independent predictors of correct results (P = 0.009 and 0.028, respectively) and did not interfere with each other. The sensitivity, specificity and accuracy of the combination of all of the tools were 98.8%, 100% and 99.2%, respectively, and the area under the receiver operating characteristic curve was 0.902 (95% CI: 0.797-0.986).

CONCLUSION

This minimally invasive procedure is easily performed and should be recommended for all patients with cervical lymphadenopathy and a history of lymphoma, avoiding the need of core-biopsy or surgical excision if recurrence was excluded.

Sensitivity of fine-needle aspiration biopsy for diagnosing and grading follicular lymphomas using a multiparameter approach in a cancer center

OBJECTIVES

The diagnosis and grading of follicular lymphomas (FLs) by fine-needle aspiration biopsy (FNAB) has not been systematically compared with core needle biopsy (CNB). We evaluated the sensitivity of FNAB in diagnosing and grading FLs using a multiparameter approach in a large cancer center.

METHODS

We retrospectively identified CNBs of lymph nodes diagnosed as FL that also had a concurrently acquired FNAB on the same site. The majority of cases had flow cytometric analysis and these results were available for interpretation of both the FNAB and CNB.

RESULTS

Out of 342 patients, CNB diagnoses included 291 (85%) low-grade (LG) FLs, 30 (9%) high-grade (HG) FLs, and 21 (6%) non-graded FLs/other. FNAB diagnoses included 194 (57%) LG FLs, 19 (6%) HG FLs, 93 (27%) non-graded FLs, 9 (3%) large B-cell lymphomas (LBCL) of follicle center origin, and 27 (7%) insufficient for diagnosis/other. Review of non-graded FLs showed 45% LG, 35% indeterminate due to polymorphous lymphoid cells with increased numbers of large cells, and 20% scant cellularity. Sensitivity of FNAB for diagnosing FL was 89%, and 66% for LG FL. The latter increased (94%), however, when grading was performed.

CONCLUSION

FNAB is highly sensitive for diagnosing FLs when cellular material for cytomorphology and flow cytometric analysis is obtained, and grading is feasible for most LG FLs. A subset of FLs composed of a polymorphous lymphoid population with increased numbers of large cells may be more difficult to grade, and HG FLs can be difficult to distinguish from CD10-positive diffuse LBCLs.

Lymphoma: current status of clinical and preclinical imaging with radiolabeled antibodies

Lymphoma is a complex disease that arises from cells of the immune system with an intricate pathology. While lymphoma may be classified as Hodgkin or non-Hodgkin, each type of tumor is genetically and phenotypically different and highly invasive tissue biopsies are the only method to investigate these differences. Noninvasive imaging strategies, such as immunoPET, can provide a vital insight into disease staging, monitoring treatment response in patients, and dose planning in radioimmunotherapy. ImmunoPET imaging with radiolabeled antibody-based tracers may also assist physicians in optimizing treatment strategies and enhancing patient stratification. Currently, there are two common biomarkers for molecular imaging of lymphoma, CD20 and CD30, both of which have been considered for investigation in preclinical imaging studies. In this review, we examine the current status of both preclinical and clinical imaging of lymphoma using radiolabeled antibodies. Additionally, we briefly investigate the role of radiolabeled antibodies in lymphoma therapy. As radiolabeled antibodies play critical roles in both imaging and therapy of lymphoma, the development of novel antibodies and the discovery of new biomarkers may greatly affect lymphoma imaging and therapy in the future.

Single-Tube Flow Cytometry Assay for the Detection of Mature Lymphoid Neoplasms in Paucicellular Samples

OBJECTIVES

Flow cytometry (FC) has become a useful support for cytomorphologic evaluation (CM) of fine-needle aspirates (FNA) and serous cavity effusions (SCE) in cases of suspected non-Hodgkin lymphoma (NHL). FC results may be hampered by the scarce viability and low cellularity of the specimens.

STUDY DESIGN

We developed a single-tube FC assay (STA) that included 10 antibodies cocktailed in 8-color labeling, a cell viability dye, and a logical gating strategy to detect NHL in hypocellular samples. The results were correlated with CM and confirmed by histologic or molecular data when available.

RESULTS

Using the STA, we detected B-type NHL in 31 out of 103 hypocellular samples (81 FNA and 22 SCE). Of these, 8 were not confirmed by CM and 2 were considered to be only suspicious. The FC-negative samples had a final diagnosis of benign/reactive process (42/72), carcinoma (27/72), or Hodgkin lymphoma (3/72).

CONCLUSIONS

The STA approach allowed obtainment of maximum immunophenotyping data in specimens containing a low number of cells and a large amount of debris. The information obtained by STA can help cytomorphologists not only to recognize but also to exclude malignant lymphomas.

Brain stereotactic biopsy flow cytometry for central nervous system lymphoma characterization: advantages and pitfalls

BACKGROUND

Brain stereotactic biopsy (SB) followed by conventional histopathology and immunohistochemistry (IHC) is the gold standard approach for primary central nervous system lymphoma (PCNSL) diagnosis. Flow cytometry (FCM) characterization of fine-needle aspiration cytology and core needle biopsies are increasingly utilized to diagnose lymphomas however, no biological data have been published on FCM characterization of fresh single cell suspension from PCNSL SB. The aim of this study was to establish the feasibility and utility of FCM for the diagnosis and characterization of brain lymphomas from a tissue samples obtained by a single SB disaggregation.

METHODS

Twenty-nine patients with a magnetic resonance suggestive for PCNSL entered the study. A median of 6 SB were performed for each patient. A cell suspension generated from manual tissue disaggregation of a single, unfixed, brain SB, was characterized by FCM. The FCM versus standard approach was prospectively compared.

RESULTS

FCM and IHC showed an high degree of agreement (89 %) in brain lymphoma identification. By FCM, 16 out of 18 PCNSL were identified within 2 h from biopsy. All were of B cell type, with a heterogeneous CD20 mean fluorescence intensity (MFI), CD10 positive in 3 cases (19 %) with surface Ig light chain restriction documented in 11 cases (69 %). No false positive lymphomas cases were observed. Up to 38 % of the brain leukocyte population consisted of CD8 reactive T cells, in contrast with the CD4 positive lymphocytes of the peripheral blood samples (P < 0.001). By histopathology, 18 B-PCNSL, only one CD10 positive (5 %), 1 primitive neuroectodermal tumor (PNET) and 10 gliomas were diagnosed. A median of 6 days was required for IHC diagnosis.

CONCLUSION

Complementary to histopathology FCM can contribute to a better characterization of PCNSL, although necrosis and previous steroid treatment can represent a pitfall of this approach. A single brain SB is a valid source for accurate FCM characterization of both lymphoma and reactive lymphocyte population, routinely applicable for antigen intensity quantification and consistently documenting an active mechanism of reactive CD8 T-lymphocytes migration in brain lymphomas. Moreover, FCM confirmed to be more sensitive than IHC for the identification of selected markers.

Lymph Node Fine-Needle Cytology of Non-Hodgkin Lymphoma: Diagnosis and Classification by Flow Cytometry

In the last decades, lymph node fine-needle cytology (FNC), coupled with flow cytometry (FC), has gained a role in the diagnosis and classification of non-Hodgkin lymphoma (NHL). The combination of FNC/FC allows the diagnosis and classification of NHL in lymph node samples with a high sensitivity and specificity by combining cytological features and specific phenotypic profiles. The present review provides a brief technical description of FC and a detailed analysis of the current markers and their combinations (diagnostic algorithm) for the diagnosis and classification of NHL. The basic principles of clonality assessment, as well as the diagnostic strengths and weaknesses of the procedure, are reported. The current diagnostic algorithms for NHL classification are critically reviewed with a focus on specific problems related to single entities. Moreover, this review provides a detailed analysis of the different clinical contexts in which FNC/FC is performed and related implications. Future and further applications of FNC/FC for NHL are also discussed.

Extranodal Lymphoproliferative Processes and Flow Cytometry

OBJECTIVE

Fine-needle aspiration (FNA) cytology is a safe and cost-effective technique for the diagnosis of lymphoproliferative processes, especially when correlated with clinical and imaging studies. However, cytology alone may be unable to detect a lymphoid neoplastic process, as architectural features are less obvious than in histologic preparations and, in certain cases, reactive processes may mimic lymphoma. Flow cytometry (FC) has been recognized as an important ancillary technique in the diagnosis of lymphoid neoplasms and it can be used in conjunction with FNA in the evaluation of lymphoproliferative processes.

STUDY DESIGN

We performed a review of the published literature concerning FC applied to the detection of salivary glands and thyroid lymphoproliferative processes, which are frequently related to autoimmune diseases and difficult to diagnose by cytomorphology alone.

RESULTS

FC is able to detect and subtype non-Hodgkin lymphomas and may contribute to the exclusion of a neoplastic process in cytologically unclear cases.

CONCLUSIONS

FC can be successfully applied in the differential diagnosis of lymphoproliferative processes in the head and neck region. The FNA-FC combined approach can reduce time to therapy and may prevent unnecessary surgical biopsies.

Fine needle aspirate flow cytometric phenotyping characterizes immunosuppressive nature of the mesothelioma microenvironment

With the emergence of checkpoint blockade and other immunotherapeutic drugs, and the growing adoption of smaller, more flexible adaptive clinical trial designs, there is an unmet need to develop diagnostics that can rapidly immunophenotype patient tumors. The ability to longitudinally profile the tumor immune infiltrate in response to immunotherapy also presents a window of opportunity to illuminate mechanisms of resistance. We have developed a fine needle aspirate biopsy (FNA) platform to perform immune profiling on thoracic malignancies. Matching peripheral blood, bulk resected tumor, and FNA were analyzed from 13 mesothelioma patients. FNA samples yielded greater numbers of viable cells when compared to core needle biopsies. Cell numbers were adequate to perform flow cytometric analyses on T cell lineage, T cell activation and inhibitory receptor expression, and myeloid immunosuppressive checkpoint markers. FNA samples were representative of the tumor as a whole as assessed by head-to-head comparison to single cell suspensions of dissociated whole tumor. Parallel analysis of matched patient blood enabled us to establish quality assurance criteria to determine the accuracy of FNA procedures to sample tumor tissue. FNA biopsies provide a diagnostic to rapidly phenotype the tumor immune microenvironment that may be of great relevance to clinical trials.

The Comparative Diagnostic Features of Canine and Human Lymphoma

The non-Hodgkin lymphomas (NHLs) are a heterogeneous family of lymphoid malignancies that are among the most common neoplasms of both dogs and humans. Owing to shared molecular, signaling, incidence, and pathologic features, there is a strong framework supporting the utilization of canine lymphoma as a comparative, large animal model of human NHL. In alignment with the biologic similarities, the current approach towards the diagnosis and classification of canine lymphoma is based upon the human World Health Organization guidelines. While this approach has contributed to an increasing appreciation of the potential biological scope of canine lymphoma, it has also become apparent that the most appropriate diagnostic philosophy must be multimodal, namely by requiring knowledge of microscopic, immunophenotypic, and clinical features before establishing a final disease diagnosis. This review seeks to illustrate the comparative similarities and differences in the diagnosis of canine lymphoma through the presentation of the microscopic and immunophenotypic features of its most common forms.

Importance of Flow Cytometry in the Cytopathologic Evaluation of Lymphoid Lesions Involving the Kidney

BACKGROUND

Cytomorphology alone is often insufficient for the diagnosis and subclassification of lymphomas, so flow cytometry (FC) may be used as an adjuvant test.

METHODS

Renal fine-needle aspirations (FNAs) performed from January 1993 to August 2014 were reviewed for FC data or a diagnosis of lymphoma.

RESULTS

A total of 586 renal FNAs were collected. Thirty-three cases (5.1%) had FC analysis. Lymphoma was diagnosed 35 times (6%), and FC was performed in 21 (60%) cases. Both cytomorphology and FC were consistent with lymphoma in 20 cases. Cytomorphology alone was diagnostic of lymphoma in 15 cases. In 28 cases, biopsy from the kidney or another site was diagnostic of lymphoma. One subsequent biopsy revealed that a kidney FNA, which showed no definitive morphologic or FC evidence of lymphoma, likely represented necrotic diffuse large B-cell lymphoma.

CONCLUSION

FC is a useful adjuvant diagnostic test for renal FNAs, particularly for subclassification and confirmation of the diagnosis when there is insufficient material for immunohistochemistry. FC should be interpreted with caution when a sample is limited or when there is suspicion of Hodgkin lymphoma, and further work-up is warranted when cytomorphology suggests lymphoma but FC is negative.

Chylothorax Associated with Chronic Lymphocytic Leukemia

An 80-year-old man who had suffered from chronic lymphocytic leukemia (CLL) and achieved complete remission was admitted to our hospital due to right pleural effusion. Thoracentesis revealed that the effusion was chyle. Lymphoscintigraphy showed an obstruction of the thoracic duct below the sternum. CD45-gated flow cytometry of the pleural effusion showed elevated numbers of CD5- and CD23-positive lymphocytes and a high serum level of soluble interleukin-2 receptor. These results suggested that the chylothorax was caused by the obstruction of the thoracic duct by the sludging of either abnormal lymphocytes of CLL or transformed malignant lymphoma cells.

Impact of flow cytometry in liver cytopathology

BACKGROUND

Fine needle aspiration (FNA) is commonly used as a diagnostic tool for the evaluation of lymphoproliferative diseases. Cytomorphology alone is often insufficient for the diagnosis and subclassification of lymphoma; therefore, flow cytometry (FC) plays an important role in the characterization of lymphoproliferative disorders. This study reviews our experience with FC on liver FNA at the Johns Hopkins Hospital.

METHODS

2,424 liver FNAs performed over a 21-year period were reviewed for clinical FC data (n=74) or a subsequent diagnosis of lymphoma in the liver without FC data (n=40).

RESULTS

In our study, 114 cases (4.7%) were included out of the 2,424 liver FNAs performed during the study period. Lymphoma was diagnosed 79 times. Cytomorphology alone was diagnostic of lymphoma in 45 cases, and in 33 cases both the cytomorphology and the FC were consistent with a diagnosis of lymphoma. Neither FC nor cytomorphology were diagnostic of lymphoma on 1 specimen. In 39 cases, FC had negative results on a lesion suspicious for lymphoma based on cytomorphology. In several nonlymphoma cases, FC provided information that allowed further subclassification of the neoplasm.

CONCLUSION

FC is a useful adjuvant diagnostic test for liver FNAs performed on patients with lymphoproliferative disorders.

Cervical lymph node diseases in children

The lymph nodes are an essential part of the body’s immune system and as such are affected in many infectious, autoimmune, metabolic and malignant diseases. The cervical lymph nodes are particularly important because they are the first drainage stations for key points of contact with the outside world (mouth/throat/nose/eyes/ears/respiratory system) – a critical aspect especially among children – and can represent an early clinical sign in their exposed position on a child’s slim neck.

Involvement of the lymph nodes in multiple conditions is accompanied by a correspondingly large number of available diagnostic procedures. In the interests of time, patient wellbeing and cost, a careful choice of these must be made to permit appropriate treatment. The basis of diagnostic decisions is a detailed anamnesis and clinical examination. Sonography also plays an important role in differential diagnosis of lymph node swelling in children and is useful in answering one of the critical diagnostic questions: is there a suspicion of malignancy? If so, full dissection of the most conspicuous lymph node may be necessary to obtain histological confirmation.

Diagnosis and treatment of childhood cervical lymph node disorders present the attending pediatric and ENT physicians with some particular challenges. The spectrum of differential diagnoses and the varying degrees of clinical relevance – from banal infections to malignant diseases – demand a clear and considered approach to the child’s individual clinical presentation. Such an approach is described in the following paper.

Evaluation of unexplained peripheral lymphadenopathy and suspected malignancy using a distinct quick diagnostic delivery model: prospective study of 372 patients

Although rapid diagnostic testing is essential in suspicious peripheral lymphadenopathy, delays in accessing them can be considerable. We investigated the usefulness of an internist-led outpatient quick diagnosis unit (QDU) in assessing patients with unexplained peripheral lymphadenopathy, focusing on the characteristics, diagnostic, and treatment waiting times of those with malignancy. Patients aged ≥ 18 years, consecutively referred from 12 primary health care centers (PHCs) or the emergency department (ED) for unexplained peripheral lymphadenopathy, were prospectively evaluated during 7 years. Diagnostic investigations were done using a predefined study protocol. Three experienced cytopathologists performed a fine-needle aspiration cytology (FNAC) systematic approach of clinically suspicious lymphadenopathy with cytomorphology and immunophenotyping analyses. We evaluated 372 patients with a mean age (SD) of 45.3 (13.8) years; 56% were women. Malignancy was diagnosed in 120 (32%) patients, including 81 lymphomas and 39 metastatic tumors. Metastatic lymphadenopathy was diagnosed by FNAC in all 39 patients and the primary tumor site was identified in 82% of them when cytomorphology and immunocytochemistry were combined. A correct diagnosis of lymphoma was reached by FNAC in 73% of patients. When accepting "suspicious of" as correct diagnosis, the FNAC diagnosis rate of lymphoma increased to 94%. Among patients with malignancy, FNAC yielded 1.3% of false negatives and no false positives. All patients with an FNAC report of correct or suspicious lymphoma underwent a surgical biopsy, as it is a mandatory requirement of the hematology department. Mean times from first QDU visit to FNAC diagnosis of malignancy were 5.4 days in metastatic lymphadenopathy and 7.5 days in lymphoma. Mean times from receiving the initial referral report to first treatment were 29.2 days in metastatic lymphadenopathy and 40 days in lymphoma. In conclusion, a distinct internal medicine QDU allows an expeditious, agile, and prearranged system to diagnose malignant peripheral lymphadenopathy. Because of the close collaboration with the cytopathology unit and the FNAC methodical approach, diagnostic and treatment waiting times of patients with malignancy fulfilled national and international time frame standards. This particular diagnostic delivery unit could help overcome the difficulties facing PHC, ED, and other physicians when trying to provide rapid access to investigations to patients with troublesome lymphadenopathy.

Immunophenotyping of paucicellular samples

Immunophenotyping of paucicellular samples may represent a diagnostic challenge in the flow cytometry (FC) laboratory routine, as the scarcity of cells limits the number of tests that can be performed. Specimens such as fine needle aspirates (FNA), human body fluids (BF), cerebrospinal fluid (CSF), or ocular fluid (OF) sent for FC investigations in the case of suspicion of lymphoma, or for lymphoma monitoring, may contain very low numbers of cells. In these cases, it is mandatory to obtain the largest amount possible of useful information from a single tube. The basic protocol described in this unit provides a method that combines the use of multiple monoclonal antibodies (MAbs) with a Boolean gating strategy to identify and quantify the main lymphocyte populations, as well as to detect lymphomatous B cells or any aberrant T cell expression, if present, in paucicellular samples.

Ultrasensitive RNA in situ hybridization for detection of restricted clonal expression of low-abundance immunoglobulin light chain mRNA in B-cell lymphoproliferative disorders

OBJECTIVES

To assess the feasibility of using a novel ultrasensitive bright-field in situ hybridization approach (BRISH) to evaluate κ and λ immunoglobulin messenger RNA (mRNA) expression in situ in B-cell non-Hodgkin lymphoma (NHL).

METHODS

A series of 110 semiconsecutive clinical cases evaluated for lymphoma with historic flow cytometric (FCM) results were assessed with BRISH.

RESULTS

BRISH light chain restriction (LCR) results were concordant with FCM in 108 (99%) of 109 evaluable cases. Additional small B-cell lymphoma cohorts were successfully evaluated.

CONCLUSIONS

BRISH analysis of κ and λ immunoglobulin mRNA expression is a sensitive tool for establishing LCR in B-cell NHL when FCM results are not available.

From cytomorphology to molecular pathology: maximizing the value of cytology of lymphoproliferative disorders and soft tissue tumors

OBJECTIVES

The field of cytopathology has been rapidly advancing in the era of molecular pathology and personalized medicine. On-site cytologic evaluation for adequacy and triaging specimens for small core biopsy or fine-needle aspiration (FNA) are often required. Cytopathologists face the challenge of how to best triage small specimens for diagnosis, molecular testing, and personalized treatment. Owing to its minimally invasive nature, FNA alone or combined with core biopsy for lymphoproliferative disorders and soft tissue tumors has gained popularity.

METHODS

Literature review and author's institutional experience are used for this review article. This article will focus mainly on lymphoproliferative disorders and soft tissue tumors.

RESULTS

Evaluation combining cytomorphology, immunohistochemistry, and/or molecular pathology is often needed to accurately diagnose and classify lymphomas and soft tissue tumors. Many molecular tests have been performed on cytologic specimens, such as tests for BRAF and RET in thyroid FNA.

CONCLUSIONS

Molecular pathology has been widely integrated into conventional cytopathology for diagnosing lymphoproliferative disorders and soft tissue tumors, and the diagnostic value of FNA on those tumors has increased significantly. Cytology will play a more important role in the era of personalized medicine.

Flow cytometry in hematological disorders

Flow cytometry with its rapidly increasing applications is being used essentially in all fields of diagnostic medicine. In hematological disorders it is most commonly used in diagnosis, characterization, prognostication and even selecting target therapy of acute leukemia and to some extent lymphomas. It is increasingly finding place in other fields of hematology i.e., non-malignant disorders of all blood cell types including RBCs and platelets along with leukocytes. In this review the authors have discussed some of these applications with an emphasis on disorders specific to pediatric patients.

Thyroid nodule as a first manifestation of Hodgkin lymphoma-report of two cases and literature review

Lymphomas account for less than 5% of thyroid malignant lesions. Vast majority of them are B-cell non-Hodgkin lymphomas (NHL), while Hodgkin lymphoma (HL) is extremely rare. Here we present two cases of HL, at baseline manifesting as a thyroid lesion. First patient, 29-year-old pregnant female, initially suspected for metastatic medullary thyroid cancer, was eventually diagnosed with mixed cellularity type of thyroid HL. Second patient, 22-year-old woman with suspicion of advanced thyroid cancer, was in the end diagnosed with an extra-lymphatic classical HL of the thyroid. In both cases, despite repeated fine-needle aspiration biopsy, cytological examination gave inconclusive or misleading results. On histopathological examination, thyroid tumor cells were positive for CD15 and CD30 antigen, which is typical for Reed-Sternberg cells. In the report authors also discuss difficulties in management as well as potential importance of novel methods such as FISH, PCR and other molecular techniques in diagnostics of thyroid lymphomas.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2896947559559648.

Tissue flow cytometry immunophenotyping in the diagnosis and classification of non-Hodgkin's lymphomas: a retrospective evaluation of 1,792 cases

A retrospective analysis of 1,792 solid tissues suggestive of lymphoma, submitted over a 12-year period, was carried out and flow cytometry (FC) results were compared with histologic findings. The final histologic diagnosis of cases documented in this report is as follows: 1,270 non-Hodgkin's lymphomas (NHL); 17 composite lymphomas; four NHL plus carcinomas; five post-transplant lymphoproliferative disorders; 105 Hodgkin's lymphomas (HL); eight acute leukemias; 42 tissue cancers; and 341 non-neoplastic diseases. A strong correlation between morphology and FC data was observed among hematological malignancies (1,268/1,304, 97.2%) with the exception of HL. Among B-NHL, FC detection of clonally restricted B-cell allowed the identification of lymphomas that were not histologically clear and the differential diagnosis between follicular lymphoma and reactive hyperplasia. A high correlation level (r = 0.83; P < 0.0001) was obtained in comparing proliferation results obtained by FC and immunohistochemistry. Among T-NHL, FC detection of an aberrant phenotype direct histologic diagnosis in cases having less than 20% of neoplastic cells. In nine cases, FC suggested the need to evaluate a neoplastic population, not morphologically evident. Results show that FC routinely performed on tissue samples suspected of lymphomas is a fundamental adjunct to morphology in the diagnosis of NHL and may enhance the performance of the histologic evaluation so as to achieve the final diagnosis. To the best of our knowledge, this is the first report in the literature of a wide series of tissues also studied by FC.

Protein analytical assays for diagnosing, monitoring, and choosing treatment for cancer patients

Cancer treatment is often hindered by inadequate methods for diagnosing the disease or insufficient predictive capacity regarding therapeutic efficacy. Targeted cancer treatments, including Bcr-Abl and EGFR kinase inhibitors, have increased survival for some cancer patients but are ineffective in other patients. In addition, many patients who initially respond to targeted inhibitor therapy develop resistance during the course of treatment. Molecular analysis of cancer cells has emerged as a means to tailor treatment to particular patients. While DNA analysis can provide important diagnostic information, protein analysis is particularly valuable because proteins are more direct mediators of normal and diseased cellular processes. In this review article, we discuss current and emerging protein assays for improving cancer treatment, including trends toward assay miniaturization and measurement of protein activity.

[Role of cytology in hematopathological diagnostics]

The role of cytology has so far been underrecognized in the diagnostic process of hematopathological questions. This article presents an algorithm which allows a stepwise work-up of cytology specimens obtained by minimally invasive ultrasound-guided fine needle aspiration in patients with unexplained lymph node swelling. Moreover, it is shown how the selective separation of cytology specimens allows the application of immunophenotypic analysis including flow cytometry and immunohistochemistry as well as molecular analyses, such as fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) strategies. With the integrative procedure presented, cytology offers an excellent cost-effective tool for the diagnostic approach of patients with suspected hematopathological malignancies allowing a high diagnostic accuracy, ideal for initial diagnosis or follow-up.

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.

Technologies supporting analytical cytology: clinical, research and drug discovery applications

The tools and techniques developed for analytical cytology have become invaluable in expanding the development of cancer screening programs and biomarker discovery for personalized medicine. Detecting cellular, molecular, and functional changes of diseased tissue as defined by quantitative analytical methodologies has enhanced the field of medical diagnostics and prognostics. The focus of this review is to outline applications and recent technical advances in flow cytometry, laser scanning cytometry, image cytometry, and quantitative image analysis, as they pertain to clinical, research, and drug discovery applications.

Endoscopic ultrasound-guided fine needle aspiration biopsy for diagnosis of lymphoproliferative disorders: feasibility of immunohistological, flow cytometric, and cytogenetic assessments

OBJECTIVES

In addition to morphology, immunophenotype and genetic abnormalities should be assessed during diagnosis and subclassification of lymphoproliferative disorders. The objective of this study was to evaluate the yield of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) using a standard 19-gauge needle for diagnosis and subclassification of lymphoma, assessing the feasibility of immunohistological, flow cytometric, and cytogenetic assessments.

METHODS

Two hundred forty patients with suspected lymphoma were referred for EUS-FNAB to our quaternary EUS center between June 2005 and December 2010. EUS-FNAB using a conventional 19-gauge needle was attempted for all patients, followed by histological assessments including immunohistological staining, flow cytometry, and cytogenetic analysis (G-band karyotyping). Among the patients, 152 were ultimately diagnosed with lymphoma. The primary outcome measure of this study was the sensitivity of histological assessment, including immunohistological staining, flow cytometry, and G-band karyotyping, for diagnosis and subclassification of lymphoma.

RESULTS

Among the 152 patients ultimately diagnosed with lymphoma, 147 patients (96.7%) were diagnosed by EUS-FNAB, and classification in accordance with the WHO (World Health Organization) system was also possible for 135 patients (88.8%) on the basis of histological findings, including immunohistological staining. Flow cytometry showed abnormal or unusual cell populations in 121 (79.6%) of the 152 patients diagnosed with lymphoma, and in 114 (90.5%) of the 126 patients diagnosed with B-cell lymphoma. Specific cytogenetic abnormalities were detected in 21 (13.8%) of the lymphoma patients.

CONCLUSIONS

EUS-FNAB using a standard 19-gauge needle has high diagnostic value for lymphoma. Immunophenotyping is usually possible, while cytogenetic abnormalities can be identified in a relatively limited number of patients.

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.

Usefulness of multiparametric flow cytometry in detecting composite lymphoma: study of 17 cases in a 12-year period

Composite lymphoma (CL) is a rare occurrence of 2 or more morphologically and immunophenotypically distinct lymphoma clones in a single anatomic site. A retrospective analysis of 1,722 solid tissue samples clinically suggestive of lymphoma was carried out in our institute during a 12-year period to evaluate the efficacy of flow cytometry (FC) in identifying CL. We report 17 CL cases. A strong correlation between morphologic findings and FC was observed in 13 cases (76%). In the 4 cases diagnosed as non-Hodgkin lymphoma plus Hodgkin lymphoma, although FC did not detect Reed-Sternberg cells, it accurately identified the neoplastic B- or T-cell component. In 3 cases, FC indicated the need to evaluate an additional neoplastic component that was not morphologically evident. Our data demonstrate that FC immunophenotyping of tissues may enhance the performance of the diagnostic morphologic evaluation of CL. To the best of our knowledge, this is the first report in the literature of a wide series of CL studied also by FC.