Cytology and immunophenotyping of low- and intermediate-grade B-cell non-Hodgkin's lymphomas with a predominant small-cell component: a study of 56 cases

Reliability of lymphoma diagnosis using combined cytologic preparations and core needle biopsy: A single-center analysis

Objectives:

The diagnosis of lymphoma on cytologic preparations and core needle biopsies (CNBs) is often challenging due to limited material that precludes additional ancillary testing for accurate classification. We describe our institutional experience with patients who ultimately received a diagnosis of lymphoma using cytologic preparations and CNB material along with additional ancillary testing.

Material and Methods:

All patients whose cytology material (fluids, cytologic smears, and cell block) and CNB resulted in a diagnosis of lymphoma, atypical lymphoid population, or suspicious for lymphoma were retrieved. Diagnoses of lymphoma followed the established nomenclatures of the World Health Organization (WHO). For all cases, the ancillary test profiles were captured and summarized.

Results:

Of 389 cases identified, 17 (4.4%) were diagnosed as atypical lymphoid cells and 31 (7.9%) were suspicious for lymphoma resulting in an indeterminate rate of 12.3%. The rest of the malignant cases (341; 87.7%) were classified using 2017 WHO lymphoid classification system. Six low-grade and 26 high-grade B-cell lymphomas were not further classified because of limited tissue. B-cell lymphomas were the largest category (73.0%): Primarily diffuse large B-cell lymphoma (21.4%), followed by follicular lymphoma (17.5%) and chronic lymphocytic leukemia/small lymphocytic lymphoma (10.9%). A total of 140 cases (36.0%) had flow cytometry results, but 30 specimens (21.4%) were insufficient. Cytogenetic and molecular studies were performed for 78 cases (20.0%).

Conclusion:

Full classification of lymphomas is possible with combined cytologic preparations and CNB material and it is an attractive first sampling modality in the diagnostic process for this disease group.

Serous fluids and hematolymphoid disorders

Diagnosing hematolymphoid neoplasm by evaluating fine-needle aspiration (FNA) cytology sample is controversial and requires experience and clinical skills. This concept becomes more challenging when evaluating hematolymphoid neoplasm in body fluid. Differentiating between low-grade lymphoma and reactive lymphocytes is often difficult by morphology alone as reactive lymphoid cells may acquire activation morphology from being exposed to different cytokines within the body fluid. However, in most cases there are specific features that may aid in differentiating small reactive from non-reactive lymphocytes including the round shape of the nucleus, the absence of visible nucleoli and the presence of fine clumped chromatin. In large cell lymphoma and leukemia cells involvement of body fluid this concept becomes less challenging. Large cell lymphoma and leukemia cells tend to have large size nuclei, less mature chromatin, and visible nucleoli with and without cytoplasmic vacuoles. However, to reach accurate diagnosis and subclassification, the utilizing of flow cytometry, to confirm monoclonality, and other ancillary studies such immunocytochemistry, cytogenetics and molecular studies is needed. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Diagnostic Cytopathology of Serous Fluids.

Flow cytometric immunophenotyping and cell block immunocytochemistry in the diagnosis of primary Non-Hodgkin's Lymphoma by fine-needle aspiration: Experience from a tertiary care center

Background:

Accurate diagnosis of Non-Hodgkin's Lymphoma (NHL) on fine-needle aspiration (FNA) specimen is challenging and requires ancillary testing.

Aim:

The feasibility of flow cytometric immunophenotyping (FCI) along with cell block immunocytochemistry (CB-ICC) as adjunct techniques in the diagnosis of NHL as per the current World Health Organization (WHO) classification was evaluated.

Materials and Methods:

All cases of suspected lymphoma underwent FNA, and the sample was triaged for light microscopic evaluation, FCI, and CB-ICC, and each case was classified as per the current WHO classification.

Results:

A total of 65 cases was analyzed which included 40 B-cell, 21 T-cell, and 4 unclassifiable lymphomas. Of 61 cases, FCI alone was contributory in 74% (45/61) cases whereas CB-ICC alone was contributory in 65.5% (40/61) cases in typing the lymphoma. In 11.4% (7/61) cases, the lymphoma could not be classified by either technique. Thus, in a total of 88.5% (54/61) cases a combination of FCI and CB-ICC from FNA enabled a diagnosis of lymphoma with its subtyping.

Conclusion:

Flow cytometric immunophenotyping and ICC on CBs are feasible on FNA material and are very useful in a suspected case of NHL especially when a biopsy may not be possible or feasible.

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.

Grading follicular lymphomas in fine-needle aspiration biopsies

BACKGROUND

The World Health Organization (WHO) recommends a 3-tier grading system (Grades 1-3) for follicular lymphomas (FLs) based on the absolute number of centroblasts per high-power microscopic field (HPF) in 10 neoplastic follicles. Grades 1 and 2 FL are still managed as indolent FLs, whereas Grade 3 FL is thought to behave more aggressively. In this study, the feasibility of grading FL using ThinPrep (TP) slides and flow cytometry (FC) was evaluated.

METHODS

Fifty-three cases of lymph node fine-needle aspiration (FNA) from patients with histologically confirmed FL (20 Grade 1, 17 Grade 2, and 16 Grade 3) were included. The number of centroblasts present in 300 lymphoid cells and in 10 HPF in TP Papanicolaou-stained slides was evaluated. The percentage of CD10-positive small cells was calculated with FC results. Statistical analysis was performed with the Jonckheer-Terpstra nonparametric trend test and the Wilcoxon rank sum test.

RESULTS

The statistical analysis demonstrated a significant upward trend in the number of centroblasts as the grades increased. Also, all 3 methods had statistically significant results to distinguish different grades of FL, except when FC was used to distinguish Grade 2 from Grade 3 FL.

CONCLUSIONS

Counting centroblasts, either in 300 lymphoid cells or per 10 HPF in TP slides, represented a statistically significant method to separate different grades of FL in FNA samples. Analysis of cell size by FC was not as reliable to distinguish different grades of FL, especially Grade 2 from 3.

Fine-needle aspiration cytology combined with flow cytometry immunophenotyping is a rapid and accurate approach for the evaluation of suspicious superficial lymphoid lesions

The authors report a prospective study on 88 samples of superficial lesions (lymph nodes, skin nodules, and breast tumors), performed by fine-needle aspiration cytology (FNAC) in 74 patients, allowing (i) morphologic analysis combined with immunophenotyping by flow cytometry (FCM) and (ii) a cytogenetic study in 33 cases. Thirty-nine FNAC (44.3%) were performed at the time of diagnosis. The cytology results were correlated with histopathologic examination in 32 cases. Forty-nine FNAC (55.7%) were performed in the context of follow-up of a lymphoma and the results were correlated with those of histopathologic examination in 14 cases. In this study, the concordance between FNAC plus FCM and histopathologic examination was 90% for low-grade non-Hodgkin's malignant lymphomas (NHLs) and 83% for high-grade NHL. The limits of this morphologic and phenotypic approach are (i) partial tumor infiltrations, (ii) Hodgkin lymphoma, and (iii) T-cell NHL. In conclusion, it may be said that this combined approach is very useful for diagnosis and follow-up of patients but requires teams experienced in the sampling technique and the morphologic diagnosis of the various types of low-grade NHL in which supplementary ancillary studies may be performed when morphology and flow cytometry immunophenoyping are not conclusive.

Diagnostic pathology of lymphoproliferative disorders

The last 20 years have seen a dramatic change in the way we classify, and therefore diagnose, lymphoma. Two decades ago, the International Working Formulation enabled diagnosis and management on the basis of H&E sections alone, with no mandatory requirement for immunophenotyping, molecular studies or any other ancillary investigations. The concept of categorisation by 'clinicopathological entities' defined by clinical features, morphology, immunophenotype and more recently, genotype, began with the Kiel, and Lukes and Collins classifications in the late 1970s, becoming fully expressed in the REAL and subsequently WHO classifications. The current, multidisciplinary approach to categorisation adds significantly to the task facing the anatomical pathologist, since it requires distribution of biopsy material to all the appropriate specialised laboratories, the gathering of a range of cross-disciplinary information, the correlation of all diagnostic findings, deduction of a definitive diagnosis and, finally, integration of all the above into a single multiparameter report. In this review, we summarise the contemporary approach to the biopsy, diagnosis and reporting of lymphoproliferative disorders.

A Simple Antigen Retrieval Method for the Optimal Demonstration of Cyclin-D1 Overexpression in Formalin-Fixed Paraffin-Embedded Cases of Mantle Cell Lymphoma

Successful diagnosis of mantle cell lymphoma (MCL) by immunohistochemistry is largely dependent on the successful demonstration of cyclin D1 overexpression in cases that fit clinical, morphologic, and immunophenotypical profiles. Accurate diagnosis in these cases is important due to the aggressive progression and poor survival times associated with this type of lymphoma. However, demonstration of cyclin D1 by immunohistochemistry on formalin-fixed, paraffin-embedded tissue is often fraught with technical difficulties, chiefly poor staining intensity largely due to insufficient antigen retrieval. The authors report a simple antigen retrieval technique that combines both heat and enzymatic treatment to demonstrate cyclin D1 overexpression. Furthermore, it appears that the antigen retrieval method is the key factor in the demonstration of cyclin D1, as detection systems with differing sensitivities (labeled streptavidin biotin [ABC] and dextran polymeric conjugate [Envision]) fail to demonstrate any significant differences in their staining intensities. This isa simple, cost-effective method that can be performed manually or can easily be adapted to suit automated staining systems.

The role of flow cytometric immunophenotyping in improving the diagnostic accuracy in referred fine-needle aspiration specimens

Flow cytometric (FCM) immunophenotyping has an important role in the diagnostic work up of fine-needle aspiration (FNA) specimens obtained from lymphoid lesions. The objective of the present study was to evaluate the feasibility of this method with respect to referred FNA specimens. One hundred and two FNA specimens referred to our laboratory for FCM analysis during the last 3 years were studied. Specimens were sent, accompanied by cytological smears, from 11 distant hospitals by ordinary mail. The evaluation of potential B-cell monoclonality, the main diagnostic issue to be resolved using FCM, was possible in 86 of these 102 cases. The remaining 16 samples could not be analyzed or adequately interpreted because of sparse or necrotic material. A monoclonal B-cell population was found in 17/86 satisfactory cases, of which 16 were histologically confirmed. Eight cases contained cells positive for the epithelial marker Ber-EP4 and were diagnosed accordingly as carcinomas. FCM analysis of specimens obtained with a clinical question of Hodgkin lymphoma or T-cell lymphomas did not yield definitive data. The time lapse between sampling and analysis (12-84 hr) did not affect the results. This probably was due to the fact that all aspirates were taken in Roswell Park Memorial Institute (RPMI) cell medium, supplemented with 50% fetal calf serum. In conclusion, this retrospective study establishes that it is possible, in the majority of cases, to refer FNA material for FCM immunophenotyping by mail, and that results regarding B-cell clonality in the case of small-cell lymphomas are reliable also after a transportation period of 3-4 days. Carcinoma may be similarly diagnosed and a diagnosis of lymphoma may be excluded in reactive proliferations. Cases with only a few atypical cells or specimens from patients suspected of having Hodgkin lymphoma or T-cell lymphomas are not suitable for analysis by FCM.

Determination of light chain restriction in fine-needle aspiration-type preparations of B-cell lymphomas by mRNA in situ hybridization

The purpose of this study was to investigate whether B-cell clonality could be demonstrated in fine-needle aspiration (FNA)-type preparations by using automated and manual in situ hybridization (ISH) systems. FNA-like preparations were made from 10 cases of B-cell lymphoma and 5 cases of reactive lymphoid hyperplasia. Kappa/lambda expression was determined using an automated mRNA ISH assay or a manual ISH system. Other variables tested included type and length of fixation, protease digestion, and time in chromogen. Clonality data were corroborated by either flow cytometry or tissue-based analysis. Optimal conditions required formalin fixation, strong protease digestion, and prolonged hybridization and chromogen times; under these conditions, monoclonality was demonstrated by in situ in 8 of 10 cases. Each of the five cases of reactive lymphoid hyperplasia showed polyclonal light chain expression by automated mRNA ISH. In situ kappa/lambda mRNA analysis of FNA-type specimens allows direct determination of monoclonality in cytologic preparations.

Superficial malignant neoplasms in southwestern Ethiopia: a cytopathological approach

The aim of this study was to describe the distributions of superficial malignant neoplasms diagnosed by fine-needle aspiration cytology (FNAC). A prospective cross-sectional study was conducted within the Jimma Teaching Hospital, Pathology Department, Jimma University during the years between September 1998 and August 2002. Cases fulfilling cytopathological evidences of superficial malignancies were included whereas deep-seated malignancies were excluded from the study. An air-dried smear stained with the Wright staining procedure was utilized for the FNAC diagnostic technique. A total of 3,200 cases were investigated during the study period where 267 (8.3%) cases were of primary superficial malignant neoplasms, with 98 cases in the peak age group of 40-59 yr (36.7%) and a median age of 38.0 yr (range, 0.2-88 yr). The most frequent superficial cytodiagnosis was breast carcinoma, 79 (29.6%) cases; followed by non-Hodgkin's lymphomas, 37 (13.9%) cases; and soft tissue sarcomas, 26 (9.7%) cases. The overall male-to-female ratio showed preponderance to female patients (1:1.3). Carcinomas were identified more frequently in those >40 yr of age whereas sarcomas were identified in those <40 yr of age (P > 0.05). The most common malignant neoplasm in women was breast carcinomas found in 74 (27.7%) cases, whereas in men non-Hodgkin's lymphomas were found in 29 (10.9%) cases. Large proportions of carcinomas (88 cases, 33.0%), lymphomas (33 cases, 12.4%), and sarcomas (20 cases, 7.5%) were detected on the trunk, head, and neck, as well as on the lower limb regions, respectively. This study uncovered different types of superficial malignant neoplasms that are prevalent in the southwestern part of Ethiopia. The most common types of cytodiagnoses such as breast carcinomas, etc. may suggest that attention be given to future high-caliber prospective studies in trying to identify some of the associated strong risk factors for the disease under study. This study may be helpful to local health planners in prioritizing some of the commonest malignancies. Some of the diagnostic challenges of lymphomas and thyroid follicular lesions were shown also. This investigation is the first in Ethiopia and therefore may act as baseline data for similar studies in the future.

Role of fine-needle aspiration cytology in breast lymphoma

Lymphomas of the breast are rare and may mimic carcinoma clinically. We investigated the ability of fine-needle aspiration (FNA) biopsy combined with adjunctive flow cytometry (FC), immunofluorescence microscopy (IFM), and immunocytochemistry (ICH) to diagnose and eventually subclassify lymphomas of the breast according to the Revised European American Lymphoma/World Health Organization classification. We retrieved 21 breast aspirates from 19 patients with a cytologic diagnosis of lymphoma or plasmacytoma over a 10-year period (1992-2002), excluding 98 benign intramammary lymph nodes and 1 atypical lymphohistiocytic proliferation (Rosai Dorfman disease). FC was performed in 15/21 aspirates, IFM in 1/21, ICH in 3/21. Histologic follow-up (HF) was obtained for 10 patients, most of them with primary lymphoma. For the remaining nine patients without HF, flow cytometric analysis, comparative morphology, or remission after chemotherapy regimens supported the cytologic diagnosis. Of 19 patients, 11 patients had a secondary lymphoma (SL) and 8 patients had a primary lymphoma (PL). FNA and FC/IFM/ICH classified 7/8 PLs as B-cell lymphomas and 1/8 PLs as plasmacytoma. However, FNA could only subclassify 3 of 8 PLs. FNA and/or FC subclassified accurately 10/11 SLs. All cases were accurately immunophenotyped as B-, T-cell non-Hodgkin's lymphomas or plasmacytoma. World Health Organization classification was achieved in 3/8 PLs (42%) and 10/11 SLs (91%; P = 0.04). Subclassification (which has an impact on long-term management and prognosis) was significantly better in SL, when a previous histologic diagnosis had already been made, when compared to PL, of which 5/8 cases (62.5%) could not be accurately classified.

Cytologic findings of marginal zone lymphoma

BACKGROUND

Low-grade lymphomas can be difficult to diagnose in cytology specimens, especially marginal zone B-cell lymphomas (MZLs). MZL is a low-grade lymphoma characterized by a heterogeneous lymphoid population, which can be difficult to distinguish from reactive processes in cytology specimens.

METHODS

Fourteen cytology specimens of MZL from 11 patients with histologically confirmed MZL (n = 10) or flow cytometry (FC)-confirmed MZL (n = 1) were reviewed, including 13 fine-needle aspiration biopsy (FNAB) specimens (salivary gland, n = 6; lung, n = 3; lymph node, n = 2; breast, n = 1; and soft tissue, n = 1) and 1 pleural effusion specimen. Cytologic preparations included air-dried and alcohol-fixed direct smears, ThinPrep(R) slides, and cell blocks. FC studies were available in six specimens.

RESULTS

All 13 FNAB specimens were composed predominantly of intermediate-sized lymphoid cells with interspersed small, round lymphocytes and transformed cells. The intermediate-sized cells displayed a moderate amount of cytoplasm, slight nuclear membrane irregularities, and inconspicuous-to-absent nucleoli. The pleural fluid contained mostly small-to-intermediate-sized, round lymphocytes. In 10 specimens, the intermediate-sized cells often showed plasmacytoid morphology, which were seen best in Diff-Quik (Mercedes Scientific Co., Inc., Sarasota, FL)-stained slides. Monocytoid cells (n = 6 specimens), plasma cells (n = 7), lymphohistiocytic aggregates (n = 11), and tingible body macrophages (n = 5) were variably identified. Lymphoepithelial lesions were not observed. Three specimens with FC studies showed a phenotype compatible with MZL, and three specimens were nondiagnostic.

CONCLUSIONS

Cytologic features suggestive of MZL included abundant intermediate-sized lymphoid cells with mild atypia in a background of small lymphocytes and transformed cells, often with plasmacytoid morphology. Flow cytometry was beneficial only in selected MZL cytology specimens. Surgical correlation may be necessary to confirm the diagnosis.

Adult T-cell leukemia/lymphoma: a cytopathologic, immunocytochemical, and flow cytometric study

BACKGROUND

Adult T-cell leukemia/lymphoma (ATLL) is a postthymic lymphoproliferative neoplasm of T cells caused by human T-cell lymphotropic virus (HTLV-1). Most cases are found in Japan, the Caribbean basin, and West Africa.

DESIGN

To identify diagnostic parameters for cytology in this neoplasm, the authors undertook a retrospective review of all ATLL samples from 1990 to 2000.

RESULTS

One hundred fourteen samples from 34 patients with the diagnosis of ATLL were reviewed: 80 cerebrospinal fluids, 7 pleural effusions, 4 bronchoalveolar lavages, 2 peritoneal effusions as well as fine-needle aspirations of 15 lymph nodes, 4 subcutaneous lesions, and 2 breast nodules. Twenty-one patients were women and 13 were men, with an age range of 30 to 71 years. Morphologically, all specimens were characterized by the presence of a polymorphous population of lymphocytes ranging from small bland-appearing lymphocytes to large atypical ones with bizarre, multilobulated nuclei (flower-like or clover leaf cells) with coarse chromatin and prominent nucleoli. The cytoplasm was deeply basophilic with occasional vacuoles. Immunocytochemistry was performed on 17 specimens from 14 patients. In all cases tested, tumor cells were immunoreactive for CD3, CD4, CD5, and CD25 and were nonimmunoreactive for CD7 and CD8. Flow cytometry was performed on 12 specimens from 9 patients. The tumor cells in all cases tested were positive for CD2, CD3, CD4, CD5, and CD25 and were negative for CD7.

CONCLUSIONS

Despite the polymorphous nature of ATLL, diagnosis can be established by close attention to nuclear cytologic features in conjunction with ancillary studies such as immunocytochemistry and/or flow cytometry.