Role of polymerase chain reaction and immunocytochemistry in the cytological assessment of lymphoid proliferations

Lymph Node Fine-Needle Cytology: Beyond Flow Cytometry

Lymph node (LN) fine-needle cytology (FNC) coupled with flow cytometry immunophenotyping provides relevant information for the diagnosis of non-Hodgkin lymphoma (NHL). Numerous studies have shown FNC samples to be suitable for different molecular procedures; in this review, some of the molecular procedures most commonly employed for NHL are briefly described and evaluated in this perspective. Fluorescence in situ hybridization and chromogenic in situ hybridization are briefly described. Polymerase chain reaction (PCR)-based assays are used to identify and quantify mutations and translocations, namely immunoglobulin (IGH) and T-cell receptor rearrangements by clonality testing and IGVH somatic hypermutations either by Sanger sequencing, single-strand conformational polymorphisms or RT-PCR strategies. High-throughput technologies (HTT) encompass numerous and different diagnostic tools that share the capacity of multiple molecular investigation and sample processing in a fast and reproducible manner. HTT includes gene expression profiling, comparative genomic hybridization, single-nucleotide polymorphism arrays and next-generation sequencing technologies. A brief description of these tools and their potential application to LN FNC is reported. The challenge for FNC will be to achieve new knowledge and apply new technologies to FNC, exploiting its own basic qualities.

Systematic review of the effectiveness of fine-needle aspiration and/or core needle biopsy for subclassifying lymphoma

CONTEXT

The World Health Organization system for lymphoma classification relies on histologic findings from excisional biopsies. In contradistinction to expert guidelines, practitioners increasingly rely on fine-needle aspiration cytology and core needle biopsies rather than excisional biopsies to diagnose lymphomas.

OBJECTIVE

To determine a rate at which fine-needle aspiration cytology and core needle biopsies, combined with flow cytometry and/or genetic techniques, can provide a diagnosis sufficient for optimal medical management of lymphoma.

DATA SOURCES

The English-language literature on fine-needle aspiration cytology and core needle biopsies for lymphoma was reviewed to identify studies that provided interpretations of all specimens regardless of whether these were deemed diagnostic.

CONCLUSIONS

Forty-two studies (1989-2012) specified the lymphoma subtypes for each diagnosis or indicated a rate at which the methods failed to provide a diagnosis. The median rate at which fine-needle aspiration cytology and core needle biopsies yielded a subtype-specific diagnosis of lymphoma was 74%. Strictly adhering to expert guidelines, which state that follicular lymphoma cannot be graded by these techniques, decreased the diagnostic yield further to 66%. Thus, 25% to 35% of fine-needle aspirates and/or core biopsies of nodes must be followed by an excisional lymph node biopsy to fully classify lymphoma.

Clonality and phenotyping analysis of alveolar lymphocytes is suggestive of pulmonary MALT lymphoma

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma, a low-grade B-cell extranodal lymphoma, is the most frequent subset of primary pulmonary lymphoma (PPL). It often associates with connective tissue disease (CTD). We aimed to evaluate the impact of concomitant CTD on diagnostic value of flow cytometry and genetic clonality analyses for the diagnostic of MALT lymphoma.

METHODS

All chest disease and pathology departments of teaching hospitals in Paris were contacted to identify patients with a histological diagnosis of PPL of the MALT subtype with or without associated CTD. We identified 44 patients in the lymphoma group; 11 had a CTD and were matched to 11 patients with CTD but without lymphoma.

RESULTS

Results of BAL analyses of MALT-PPL showed normal cellularity (370 cells/mm(3) [range 21-2300]) but increased proportion of lymphocytes (31.5% [80-2]) of the B-cell subtype (20% [1-88]). A B-cell clone was detected in 82% of cases, and specificity of clonality was 90%. Interestingly, BAL analysis results different by presence or not of a CTD. The frequency of B lymphocyte alveolitis was significantly greater in MALT patients without than with CTD (34% vs 6.5%, p = 0.007). However, BAL results for patients with CTD did not differ between those with and without lymphoma.

CONCLUSION

BAL results may be highly suggestive of pulmonary MALT lymphoma. The proportion of B-cells may vary depending on the presence of an associated CTD, but clonality analyses remained informative for the diagnostic of MALT lymphoma.

Clonal B-cell population in a reactive lymph node in acquired immunodeficiency syndrome

A 40-year-old female, HIV positive, stage C, since 4 years, complained of a right cervical lymph node swelling. Two years before, the patient had been diagnosed with follicular B-cell non-Hodgkin lymphoma (FL); she had been treated with four cycles of multiagent chemotherapy plus rituximab, the last cycle being administered 10 months before coming to our attention. An ultrasound (US) guided fine-needle cytology (FNC) showed an atypical lymphoid cell proliferation. The phenotype evidenced by flow cytometry (FC) analysis was D5: 10%, CD19: 49%, CD23: 10%, FMC7: 0%, CD10: 40%, CD10/19: 40%, lambda light chain 40%, kappa light chain 0%. FDG-positron emission tomography (PET/CT) scan showed positivity in the corresponding cervical area. Since low LDH values and a reduced lymph node size were observed, the lymph node was therefore excised; the histology revealed a reactive hyperplastic lymph node with florid follicular pattern. A subsequent PCR analysis, performed on DNA extracted from a whole histological section, did not evidence IgH rearrangement. The patient is currently undergoing strict clinical and instrumental follow-up, including PET every 3 months; after 13 months, she is alive without recurrence of lymphoma. Clonal B-cell populations in non-lymphomatous processes have been described in mucosa-associated lymphoid cell populations and reactive lymph nodes, and are considered non-malignant, antigen driven, proliferations of B-lymphocytes determined by an abnormal response to bacterial or viral antigen stimulation. The present case occurred in an HIV patient and was clinically complex because of the patient's history of FL. This experience suggests much attention in the evaluation of radiological, cytological, and FC data and in clinical correlation in patients suffering from autoimmune or immunodeficiency syndromes.

Cytologic evaluation of lymphadenopathy associated with mycosis fungoides and Sezary syndrome: role of immunophenotypic and molecular ancillary studies

BACKGROUND

The most common presenting site of extracutaneous disease in mycosis fungoides and Sezary syndrome is the peripheral lymph node. Although fine-needle aspiration biopsy has been shown to be a valuable diagnostic technique in evaluating lymphadenopathy, its utility in patients with cutaneous T-cell lymphoma has not been extensively studied. With fine-needle aspiration biopsy, material can be collected for ancillary diagnostic studies and for morphologic evaluation.

METHODS

The authors report a series of 11 fine-needle aspiration biopsy specimens from 10 mycosis fungoides and Sezary syndrome patients. Flow cytometric immunophenotyping and T-cell receptor gamma chain polymerase chain reaction were performed on fine-needle aspiration biopsy material and correlated with cytologic findings.

RESULTS

Seven of 10 patients had lymph node involvement by cutaneous T-cell lymphoma, with 3 cases exhibiting large-cell transformation and 4 cases exhibiting a small-cell pattern. Flow cytometric immunophenotyping identified an abnormal T-cell population in 6 cases. A clonal T-cell rearrangement by T-cell receptor gamma chain polymerase chain reaction (TCR-gamma PCR) was identified in 1 case in which insufficient events were present for evaluation by flow cytometry and in 1 case in which flow cytometry was not diagnostic of T-cell lymphoma. Two cases showed involvement by classic Hodgkin lymphoma diagnosed by immunohistochemistry on cell block material.

CONCLUSIONS

Fine-needle aspiration biopsy in conjunction with immunophenotyping and T-cell receptor gamma chain polymerase chain reaction is significantly useful in evaluation of lymphadenopathy in patients with mycosis fungoides and Sezary syndrome, especially for triaging lymph nodes that would otherwise not be sampled or for evaluating multiple lymph nodes.

[Fine-needle aspiration cytology. Aspects of a minimally invasive diagnostic procedure]

All practicable applications of fine-needle aspiration cytology (FNAC) for palpable tumors or non-palpable lesions guided with endoscopic and imaging procedures are presented. Multidisciplinary procedures and the technical and biological aspects of FNAC are presented. Indications and diagnostic challenges of FNAC on selected organs and neoplasms are discussed based on personal experience and the literature. Skilled and well-trained cytopathologists, the quality of the aspirate and the cytological preparation as well as supplementary immunocytochemical and molecular genetic analyses are mandatory for reliable diagnostic results. The indications and advantages of liquid-based techniques are discussed.

Applications of molecular techniques to fine-needle aspiration biopsy

The effectiveness of fine-needle aspiration biopsy (FNAB) for rendering a specific diagnosis can be improved by applying several ancillary modalities. This review details several applications of molecular techniques using FNAB specimens with an emphasis on those used for patient care. A detailed search of the literature was conducted to collect all reports that used FNAB for different types of molecular tests. Several types of molecular tests, including in-situ hybridization, polymerase chain reaction, Southern blotting, and gene microarrays using FNAB specimens have been reported. These tests have been used with different organ systems and different objectives, including the detection of cancer cells, diagnosis, distinction of benign and malignant disease, prediction of response to chemotherapy, risk assessment, and selection of patients for targeted therapy. Except for a few tests such as assessment of HER2/neu for gene amplification in breast cancer, detection of clonality in hematopoietic neoplasms, and specific chromosomal translocations in the former and in the diagnosis of soft tissue sarcoma, most of the molecular tests using FNAB specimens are currently investigational. The reported literature indicates the excellent potential of using material procured from FNAB for almost any type of molecular test. Whereas few of these tests alone are used for patient care, some of them have the potential for clinical use in the near future.