Role of ancillary techniques in diagnosing and subclassifying non-Hodgkin's lymphomas on fine needle aspiration cytology

Diagnostic Discrepancies in Small-volume Biopsy for the Initial Diagnosis, Recurrence, and Transformation of Follicular Lymphoma: A Multi-Institutional Collaborative Study

Small-volume biopsies (SVBs) including fine-needle aspiration (FNA), cell block, and needle core biopsies (NCB) are increasingly utilized to diagnose and guide the clinical management of lymphoma. We established a multi-institutional interdisciplinary collaboration of cytopathologists, hematopathologists, and oncologists focused on the role of SVB in the management of patients with follicular lymphoma (FL). To assess the performance characteristics of SVB in this setting, we evaluated all consecutive SVBs performed for clinical indications of initial diagnosis, recurrence, or transformation of FL over a 5-year period and focused on the 182 that had at least one subsequent biopsy within 3 months as part of the same clinical work-up. The most common outcome of a subsequent biopsy as part of the same clinical work-up was a more specific diagnosis usually assigning the pathologic grade (111/182, 61%), followed by a complete agreement with the SVB (24/182, 13%), and change from nondiagnostic on initial biopsy to diagnostic on subsequent biopsy (21/182, 12%). A minority resulted in a diagnostic change from benign to lymphoma (17/182, 9%), a change in FL grade (5/182, 3%), or change in the lymphoma diagnostic category (4/182, 2%). There were no cases where an initial diagnosis of lymphoma was overturned. The distribution of discrepancies was similar across initial SVB types (FNA, FNA + cell block, NCB with or without FNA). Tissue limitations were noted in a minority of cases (53/182, 29%) and were enriched among initially nondiagnostic biopsies (16/21, 76%). Flow cytometry immunophenotyping was performed in the majority of cases both at the first and last biopsy (147/182, 81%). SVB can be a powerful method to detect FL in various clinical indications, with discrepant cases mostly resulting from a refinement in the initial diagnosis.

Cytological Diagnosis of Aggressive Small-Cell Lymphomas

BACKGROUND

Despite their sometimes deceivingly bland appearance, some small-cell lymphomas are very aggressive and the prognosis of patients depends on a prompt diagnosis that allows the initiation of appropriate therapy.

SUMMARY

The present review discusses the salient cytological features of the most common aggressive small-cell lymphomas and then proceeds to analyze their main diagnostic criteria, including the usage of ancillary techniques.

KEY MESSAGES

Lymph node fine-needle aspiration cytology is a fast, safe, cheap, minimally invasive, and accurate procedure that can be used for a prompt and accurate diagnosis of lymphomas.

Diagnostic accuracy of Thinprep® in cervical lymph node aspiration: Assessment according to the Sydney system

BACKGROUND

Fine-needle aspiration cytology (FNAC) is a reliable technique that has been used for many years in lymphadenopathy diagnosis. Although conventional smear is the standard approach in FNAC, liquid-based cytology (LBC) is accepted as an alternative method. Reporting standardization is a significant gap in fine-needle aspiration cytology, leading to failure in pathologist-clinician dialog and interobserver variability. In 2020, an expert panel proposed the Sydney system for classifying and reporting lymph node aspiration cytology. This study aimed to evaluate the diagnostic accuracy of LBC in lymph node aspiration cytology under the guidance of the Sydney system.

METHODS

Five hundred-four LBC samples were reevaluated and classified according to the Sydney system. Of these, n = 24 were categorized as L1-inadequate/non-diagnostic, n = 283 as L2-benign, n = 36 as L3- atypical cells of undetermined significance/atypical lymphoid cells of uncertain significance (AUS/ALUS), n = 48 as L4-suspicious, and n = 113 as L5-malignant. Four hundred-one samples were histopathologically confirmed. The diagnostic accuracy of LBC and the risk of malignancy for each Sydney category were calculated.

RESULTS

The results were as follows: sensitivity 98.97%; specificity 98.60%; positive predictive value 94.80%; negative predictive value 99.29%; and overall diagnostic accuracy 98.75%. The ROM was 16.6% for L1, 0.7% for L2, 88.8% for L3, and 100% for L4 and L5.

CONCLUSION

LBC is suitable for use in lymph node aspiration under the guidance of the Sydney system and has high diagnostic accuracy. Future comprehensive studies will increase the applicability of the Sydney system and minimize interobserver variability.

A Novel Approach to Classification and Reporting of Lymph Node Fine-Needle Cytology: Application of the Proposed Sydney System

Fine-needle cytology (FNC) is a useful diagnostic tool in the first line evaluation of lymphadenopathy of unknown aetiology. Nevertheless, considering the large number of conditions presenting as lymphadenopathy, lymph node cytology represents a challenging scenario. Recently, an expert panel published the proposal of the Sydney system for performing classification and reporting of lymph node cytopathology; the aim of the present study was to evaluate the applicability of this system. Thus, 300 lymph node FNCs performed over 1 year were reviewed and categorized according to the Sydney system classification. Overall, n = 20 cases (6.7%) were categorized as L1-inadequate/non-diagnostic; n = 104 (34.7%) as benign (L2); n = 25 (8.3%) as atypical (L3); n = 13 (4.3%) as suspicious (L4), and n = 138 (46%) as malignant (L5). FNC diagnoses were correlated with histopathologic and clinical follow-up to assess the diagnostic accuracy and the risk of malignancy (ROM) for each diagnostic category. Statistical analysis showed the following results: sensitivity 98.47%, specificity 95.33%, positive predictive value 96.27%, negative predictive value 98.08%, and accuracy 97.06%. The ROM was 50% for the category L1, 1.92% for L2, 58.3% for L3, and 100% for L4 and L5. In conclusion, FNC coupled with ancillary techniques ensures satisfactory diagnostic accuracy and the implementation of the Sydney system may improve the practice of cytopathologists.

Assessment of risk of malignancy by application of the proposed Sydney system for classification and reporting lymph node cytopathology

BACKGROUND

Fine-needle aspiration cytology (FNAC) is one of the most commonly used techniques for evaluating lymphadenopathy. Recently, the Sydney system was proposed for assessing the performance, classification, and reporting of lymph node (LN) cytopathology. The present study was conducted to assess the risk of malignancy associated with each of the diagnostic categories of the proposed Sydney system.

METHODS

This was a 2-year retrospective study of LN-FNAs; cytologic diagnoses were categorized by the proposed Sydney system. Cytological diagnoses were correlated with the corresponding histopathological diagnoses to assess diagnostic accuracy and risk of malignancy for each diagnostic category.

RESULTS

Of 23,335 FNAs during the study period, 6983 (30%) were performed on LNs. Of these, 289 (4.1%) cases were reported as nondiagnostic/inadequate (L1); 3397 (48.6%) were reported as benign (L2); 33(0.5%) as atypical cells of undetermined significance (L3), 96 (1.4%) as suspicious for malignancy (L4) and 3168 (45.4%) as malignant (L5). Subsequent histopathology was available for 618 (8.8%) cases. On cytohistopathologic correlation, 552 (89.3%) were concordant and 66 (10.7%) discordant. The overall sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of LN-FNA were 79.9%, 98.7%, 98.4%, 83.1%, and 89.3%, respectively. The risk of malignancy was 27.5% for the nondiagnostic category, 11.5% for the benign, 66.7% for the atypical, 88% for the suspicious, and 99.6% for the malignant categories.

CONCLUSIONS

FNAC has high diagnostic accuracy for the diagnosis of various LN pathologies. Application of the proposed Sydney system can help in achieving uniformity and reproducibility in cytologic diagnoses and also help in risk-stratification on cytology.

A Proposal for the Performance, Classification, and Reporting of Lymph Node Fine-Needle Aspiration Cytopathology: The Sydney System

BACKGROUND

The evaluation of lymph nodes (LN) by fine-needle aspiration cytology (FNAC) is routinely used in many institutions but it is not uniformly accepted mainly because of the lack of guidelines and a cytopathological diagnostic classification. A committee of cytopathologists has developed a system of performance, classification, and reporting for LN-FNAC.

METHODS

The committee members prepared a document that has circulated among them five times; the final text has been approved by all the participants. It is based on a review of the international literature and on the expertise of the members. The system integrates clinical and imaging data with cytopathological features and ancillary techniques. The project has received the endorsement and patronage of the International Academy of Cytology and the European Federation of the Cytology Societies.

RESULTS

Clinical, imaging, and serological data of lymphadenopathies, indications for LN-FNAC, technical procedures, and ancillary techniques are evaluated with specific recommendations. The reporting system includes two diagnostic levels. The first should provide basic diagnostic information and includes five categories: inadequate/insufficient, benign, atypical lymphoid cells of undetermined/uncertain significance, suspicious, and malignant. For each category, specific recommendations are provided. The second diagnostic level, when achievable, should produce the identification of specific benign or malignant entities and additional information by utilizing ancillary testing.

CONCLUSION

The authors believe that the introduction of this system for performing and reporting LN-FNAC may improve the quality of the procedure, the report, and the communication between cytopathologists and the clinicians. This system may lead to a greater acceptance and utilization of LN-FNAC and to a better interdisciplinary understanding of the results of this procedure.

Role of Ancillary Techniques in Fluid Cytology

The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.

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.

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.

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.

Lymph node fine needle cytology in the staging and follow-up of cutaneous lymphomas

Background

Lymph nodal involvement is an important clinical-pathological sign in primary cutaneous lymphoma (PCL), as it marks the transformation/evolution of the disease from localized to systemic; therefore the surveillance of lymph nodes is important in the staging and follow up of PCL. Fine needle cytology (FNC) is widely used in the diagnosis of lymphadenopathies but has rarely been reported in PCL staging and follow-up. In this study an experience on reactive and neoplastic lymphadenopathies arisen in PCL and investigated by FNC, combined to ancillary techniques, is reported.

Methods

Twenty-one lymph node FNC from as many PCL patients were retrieved; 17 patients had mycosis fungoides (MF) and 4 a primary cutaneous B-cell lymphoma (PBL). In all cases, rapid on site evaluation (ROSE) was performed and additional passes were used to perform flow cytometry (FC), immunocytochemistry (ICC) and/or polymerase chain reaction (PCR) to assess or rule out a possible clonality of the corresponding cell populations.

Results

FNC combined with FC, ICC, and PCR identified 12 cases of reactive, non specific, hyperplasia (BRH), 4 dermatopathic lymphadenopathy (DL), 4 lymph nodal involvement by MF and 1 lymph nodal involvement by cutaneous B-cell lymphoma.

Conclusions

FNC coupled with ancillary techniques is an effective tool to evaluate lymph node status in PCL patients, provided that ROSE and a rational usage of ancillary techniques is performed according to the clinical context and the available material. The method can be reasonably used as first line procedure in PCL staging and follow up, avoiding expensive and often ill tolerated biopsies when not strictly needed.

Cytopathology in the diagnosis of lymphoma

FNA is a simple, safe, and an inexpensive sampling technique that plays an important role in the evaluation of lymphadenopathy. The key to enhancing the accuracy of FNA diagnosis of lymphoma is the multi parameter approach in which the cytomorphologic features are evaluated in correlation with the results of ancillary studies and clinical context. A full understanding of the current lymphoma classification, clinical features associated with each lymphoma subtype and the impact of the diagnosis on patient management is essential in FNA diagnosis of lymphoma. It is also important to recognize the limitations of FNA in the primary diagnosis of some subtypes of lymphoma, and tissue biopsy should be recommended for a definitive diagnosis and subclassification in such cases.

Fine-needle aspiration cytology of orbital and eyelid lesions

Fine-needle aspiration cytology (FNAC) of orbital lesions is now increasingly popular. Because of its unique location and the occurrence of varieties of lesions, diagnosis of orbital lesion is a challenge to the cytopathologists. FNAC of orbital and eyelid tumors is a suitable diagnostic technique that necessitates close co-operation between the ophthalmologist and pathologist. No radical procedure should be planned on the basis of FNAC, but it allows the diagnosis of a new primary lesion or the recurrence or metastasis of a tumor and can be done to identify lesions that require either specific medical therapy, as in nonresectable, inflammatory, and lymphoid tumors, or limited surgery for benign resectable neoplasms. With the help of various ancillary techniques a definitive diagnosis is possible on orbital and adnexal lesions. It is essential to have a detailed knowledge on the FNAC of these lesions and their potential pitfalls. In this present review, we have discussed various orbital lesions, their clinical presentations, cytomorphology, and ancillary techniques to confirm the diagnosis.

Immunoglobulin heavy-chain fluorescence in situ hybridization-chromogenic in situ hybridization DNA probe split signal in the clonality assessment of lymphoproliferative processes on cytological samples

BACKGROUND

The human immunoglobulin heavy-chain (IGH) locus at chromosome 14q32 is frequently involved in different translocations of non-Hodgkin lymphoma (NHL), and the detection of any breakage involving the IGH locus should identify a B-cell NHL. The split-signal IGH fluorescence in situ hybridization-chromogenic in situ hybridization (FISH-CISH) DNA probe is a mixture of 2 fluorochrome-labeled DNAs: a green one that binds the telomeric segment and a red one that binds the centromeric segment, both on the IGH breakpoint. In the current study, the authors tested the capability of the IGH FISH-CISH DNA probe to detect IGH translocations and diagnose B-cell lymphoproliferative processes on cytological samples.

METHODS

Fifty cytological specimens from cases of lymphoproliferative processes were tested using the split-signal IGH FISH-CISH DNA probe and the results were compared with light-chain assessment by flow cytometry (FC), IGH status was tested by polymerase chain reaction (PCR), and clinicohistological data.

RESULTS

The signal score produced comparable results on FISH and CISH analysis and detected 29 positive, 15 negative, and 6 inadequate cases; there were 29 true-positive cases (66%), 9 true-negative cases (20%), 6 false-negative cases (14%), and no false-positive cases (0%). Comparing the sensitivity of the IGH FISH-CISH DNA split probe with FC and PCR, the highest sensitivity was obtained by FC, followed by FISH-CISH and PCR.

CONCLUSIONS

The split-signal IGH FISH-CISH DNA probe is effective in detecting any translocation involving the IGH locus. This probe can be used on different samples from different B-cell lymphoproliferative processes, although it is not useful for classifying specific entities. Cancer (Cancer Cytopathol) 2012;. © 2012 American Cancer Society.

Value of fine needle aspiration cytology in head and neck lymphoma: experience in a head and neck cancer unit in the United Kingdom

CONCLUSION

In our experience, fine needle aspiration cytology (FNAC) combined with immunocytochemistry/flow cytometry in the investigation of lymphoma presenting in the neck is highly valuable. In our unit it has a sensitivity of 95.5% and a positive predictive value (PPV) of 96.8% and is the first-line investigation in suspected lymphoma. It enables planning of radiological and haematological investigations and obviates panendoscopy as part of the staging protocol.

OBJECTIVE

Lymphoma commonly presents to otolaryngologists. The aim of our study was to evaluate the accuracy of FNAC in lymphoma presenting in the neck at our institute.

METHODS

Data were collected retrospectively between 2003 and 2007. Separate searches for cytological and histopathological diagnosis of lymphoma on cervical lymph node biopsies were cross-referenced. Immunocytochemistry stains used were recorded.

RESULTS

A total of 121 cases met the inclusion criteria. The FNAC diagnosis of lymphoma was correct on lymph node biopsy in 68.6% (83/121). In 18 (14.9%) cases a false-negative result and in 3 (2.5%) cases a false-positive result was seen. In all, 17 (14.0%) cases were non-diagnostic (11 inadequate and 6 suspicious). In 16/20 (80.0%) cases of wrong diagnosis, immunocytochemistry had not been performed. Flow cytometry and immunocytochemistry were used in 67 cases and the FNAC diagnosis had a sensitivity of 95.5% and a PPV of 96.8% in this group.

Long-term reversibility of renal dysfunction associated to light chain deposition disease with bortezomib and dexamethasone and high dose therapy and autologous stem cell transplantation

A 63-year-old woman presented with progressive renal insufficiency, until a glomerular filtration rate (GFR) of 12 mL/min. A renal biopsy demonstrated glomerular deposition of immunoglobulin κlight chain. The presence of a small population of monoclonal plasmacytes producing an only light κmonoclonal component was demonstrated and Bortezomib and Dexamethasone (BD) was provided as initial therapy. After seven courses of therapy, renal function improved without dialysis requirements up to a GFR 31 mL/min. Under hematological complete response (HCR) the patient underwent high dose of melphalan (HDM) and autologous peripheral blood stem cell transplant. Fifty-four months later the patient remains in HCR and the GFR has progressively improved up to 48 mL/min. This report describes a notably renal function improvement in a patient with Light Chain Deposition Disease after therapy with BD followed by HDM, which can support this treatment as a future option for these patients.

The utilization of fine needle aspiration biopsy (FNAB) and flow cytometry (FC) in the diagnosis and classification of non-Hodgkin B-cell and T-cell lymphomas

The subtypes of non-Hodgkin lymphomas may have similar morphology, but have a wide variation in origin, immunophenotype and biological features. Many ancillary investigations are available to help overcome these problems, including fine needle aspiration biopsy (FNAB) and flow cytometry (FC). FNAB coupled with FC can reliably distinguish between reactive and neoplastic lymphoid populations. It can be used in the diagnosis and classification of many lymphomas, obviating the need for surgical biopsy in a significant number of patients.

Laser scanning cytometry: capturing the immune system in situ

Until recently, it has not been possible to image and functionally correlate the key molecular and cellular events underpinning immunity and tolerance in the intact immune system. Certainly, the field has been revolutionized by the advent of tetramers to identify physiologically relevant specificities of T cells, and the introduction of models in which transgenic T-cell receptor and/or B-cell receptor-bearing lymphocytes are adoptively transferred into normal mice and can then be identified by clonotype-specific antibodies using flow cytometry in vitro, or immunohistochemistry ex vivo. However, these approaches do not allow for quantitative analysis of the precise anatomical, phenotypic, signaling, and functional parameters required for dissecting the development of immune responses in health and disease in vivo. Traditionally, assessment of signal transduction pathways has required biochemical or molecular biological analysis of isolated and highly purified subsets of immune system cells. Inevitably, this creates potential artifacts and does not allow identification of the key signaling events for individual cells present in their microenvironment in situ. These difficulties have now been overcome by new methodologies in cell signaling analysis that are sufficiently sensitive to detect signaling events occurring in individual cells in situ and the development of technologies such as laser scanning cytometry that provide the tools to analyze physiologically relevant interactions between molecules and cells of the innate and the adaptive immune system within their natural environmental niche in vivo.

The spectrum of coincident entities with small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) diagnosed by cytology

BACKGROUND

The cytologic diagnosis of Small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) often relies on finding a small lymphoid population with the characteristic immunoprofile by ancillary testing. There are only a few reports of other processes identified with SLL/CLL. The aim of this study was to review the fine needle aspiration (FNA) and touch prep (TP) diagnoses of SLL/CLL in order to identify any coincident entities.

MATERIALS AND METHODS

We retrospectively reviewed all FNA and TP cytology cases between January 2005 and May 2009 with a diagnosis of SLL/CLL to determine the presence of any coincident process.

RESULTS

We identified 29 cases, including 23 FNAs and six TPs, from 23 patients. Ancillary studies were utilized in 97% of the cases, including flow cytometry (FC, 79%), immunohistochemistry (IHC, 55%), fluorescent in situ hybridization studies (24%) and special stains (7%). Coincident entities were identified in nine cases (31%) and included seven (28%) neoplastic entities (Hodgkin lymphoma [HL], adenocarcinoma, squamous cell carcinoma, seminoma) and two (7%) non-neoplastic entities (infection and immunoglobulin containing cells). Six cases (21%) suspicious for large cell transformation were also identified.

CONCLUSION

In our review of SLL/CLL, coincident entities were present in 31% of the cases and included a spectrum of non-neoplastic and neoplastic processes. FC was the most frequently utilized ancillary test, but IHC provided important information by excluding a mantle cell lymphoma or confirming a coincident process. Thus, cytomorphologic evaluation in these patients is important due to the high risk of a coincident process that may not be apparent by FC alone and may require clinical management.

Use of flow cytometric immunophenotyping to refine the cytological diagnosis of canine lymphoma

The diagnosis of canine lymphoma is a multi-step process involving clinical examination, diagnostic imaging, cytology, haematology, biochemical profiling, histopathology and ancillary techniques such as flow cytometry (FC). In human medicine, FC (in addition to cytology) is reported to increase the accuracy of diagnosis of most lymphoma sub-types. In dogs, FC can add a number of useful diagnostic features to the morphological evaluation of lymphoma including the evaluation of B or T cell lineage, antigen quantification and evaluation of aberrant patterns, the assessment of clonality, staging and the evaluation of minimal residual disease. In comparison to other immunophenotyping techniques, FC is rapid and easy to perform and 'gating' techniques can resolve mixed cell populations although the use of fresh samples is required and the appropriate equipment and its maintenance are quite expensive. The use of FC to refine cytological diagnosis could be further enhanced by the use of a multi-parametric approach and by the development of a wider panel of standardised canine-specific antibodies.

Fine needle aspiration cytology and flow cytometry immunophenotyping of non-Hodgkin lymphoma: can we do better?

OBJECTIVE

To evaluate the diagnostic efficiency of fine needle aspiration cytology/flow cytometry (FNAC/FC) in the diagnosis and classification of non-Hodgkin lymphoma (NHL) in a series of 446 cases and to compare the results with those of previous experiences to evaluate whether there had been an improvement in FNAC/FC diagnostic accuracy.

METHODS

FNAC/FC was used to analyse 446 cases of benign reactive hyperplasia (BRH), NHL and NHL relapse (rNHL) in 362 lymph nodes and 84 extranodal lesions. When a diagnosis of NHL was reached, a classification was attempted combining FC data and cytological features. Sensitivity, specificity and positive and negative predictive values (PPV and NPV) of FNAC/FC in the diagnosis and classification of NHL were calculated and compared with those available in the literature.

RESULTS

FNAC/FC provided a diagnosis of NHL and rNHL in 245 cases and of BRH in 188 cases. In nine cases, the diagnosis was 'suggestive of NHL' (sNHL) and in four cases was inadequate. Histology and clinical follow-up confirmed 102 cases of NHL and detected one false positive. In 18 cases of BRH diagnosed by FNAC/FC, histological examination revealed 14 BRH and four NHL (false negatives). All nine cases diagnosed as sNHL were confirmed by histology. Including sNHL cases as false negatives, statistical analysis showed 94.9% sensitivity, 99.4% specificity, 99.6% PPV and 93.4% NPV in the diagnosis of NHL. A specific subtype was diagnosed in 125 cases and confirmed in 67 of 70 cases that had histological biopsies. Statistical analysis did not demonstrate significant improvements between the present series and previous studies either in diagnosis or in classification of NHL.

CONCLUSIONS

FNAC/FC is a fundamental tool in the diagnosis and classification of NHL but the exiguity of diagnostic material and other technical and clinical limitations will probably continue to limit further improvement of the technique.

Clinical applications of slide-based cytometry--an update

Slide-based cytometric approaches open the possibility to obtain quantitative and objective data from specimens that so far have not been accessible to this kind of analysis. In this review, we will highlight the specific advantages of slide-based cytometry (SBC) and show the applications that have been established for clinical samples. Focuses are cytomic analyses of oncological and hematological samples where the slide-based concept turned out to open new dimensions in understanding underlying cellular networks. We review the recent literature and point out future applications.

Immunocytochemical typing of primary tumors on fine-needle aspiration cytologies of lymph nodes

The aim of this study was to analyze the role of immunocytochemistry as an ancillary method on routine FNACs of enlarged lymph nodes, using different markers. In a validating cohort study all patients had confirmatory histological and/or clinical follow-up. 10 FNACs were analyzed for the differentiation of Non-Hodgkin Lymphoma (NHL) from metastatic carcinoma (MC), 30 cases to identify the sites of metastatic unknown primary tumors and 16 cases were checked to confirm clinical suspicion of a specific MC. Accuracy to differentiate NHL from MC was 100%, 92.3% to identify a primary tumor site of MC, and 100% to confirm a clinical suspicion of a specific MC. In 7 cases, the site of the primary tumor remained clinically unknown. Application of immunocytochemical markers on the same slide used for microscopic diagnosis is a useful tool in the routine assessment of FNACs of lymph nodes.

Cytopathological diagnosis in a cancer registry: a useful diagnostic tool?

BACKGROUND

To assess the role of cytology in tumor diagnosis and to explore the potential of this technique to improve tumor registry quality, the authors investigated the role of cytology as a diagnostic tool in registry databases.

METHODS

Through the Italian Network of Cancer Registry (AIRTum) archive, the authors retrieved tumors diagnosed during the years 1983-2002 from several registries, Varese, Torino, Ragusa, Ferrara, Genova, and the Tuscan Cancer Registry. The authors then analyzed the amount of morphological confirmation by topographic code, distinguishing cytological from histological diagnosis. The authors analyzed, only for the Tuscan Cancer Registry, the amount of morphological confirmation by both histological and cytological diagnosis and demonstrated the variation of cytological confirmation with stage of tumor.

RESULTS

The better morphological modality for diagnosis was rarely cytology, particularly among lung and pleural tumors; when considered together with histological analysis, cytology examination was often reported in cervical uterine and breast tumors. The usefulness of cytology increases with tumor stage, particularly in sites where biopsy is performed with difficulty.

CONCLUSIONS

Cytology may be useful to improve tumoral characterization in advanced stages or in sites inaccessible for histology; moreover, cytology is useful as an initial detector of pathology, prior to histology. A prospect of improvement in diagnostic cytopathology and the use of ancillary techniques, such as molecular biology, could help clinicians and could increase the accuracy of cancer registration.

Combined applications of fine needle aspiration cytology and flow cytometric immunphenotyping for diagnosis and classification of non Hodgkin lymphoma

Aims and objectives

In this present study we have evaluated the feasibility of sub-classification of non-Hodgkin's lymphoma (NHL) cases according to World Health Organization's (WHO) classification on fine needle aspiration cytology (FNAC) material along with flow cytometric immunotyping (FCI) as an adjunct.

Materials and methods

In this five years study, only cases suggested or confirmed as NHL by FNAC were selected and FCI was performed with a complete panel of antibodies (CD3, CD2, CD 4, CD5, CD8, CD7, CD10, CD19, CD20, CD23, CD45, κ and λ) by dual color flow cytometry. Both cytologic findings and FCI data were interpreted together to diagnose and sub-classify NHL according to WHO classification. Wherever possible the diagnoses were compared with cytology.

Results

There were total 48 cases included in this study. The cases were classified on FNAC as predominant small cells (12), mixed small and large cells (5) and large cells (26). In five cases a suggestion of NHL was offered on FNAC material and these cases were labeled as NHL not otherwise specified (NHL-NOS). Flow cytometry could be performed in 45 cases (93.8%) and in rest of the three cases the material was inadequate because of scanty blood mixed aspirate. Light chain restriction was demonstrated in 30 cases out of 40 cases of B-NHL (75%). There were 15 cases each of κ and λ light chain restriction in these 30 cases. With the help of combined FCI and FNAC, it was possible to sub-classify 38 cases of NHL (79%) according to WHO classification. Combined FNAC and FCI data helped to diagnose 9 cases of small lymphocytic lymphoma (SLL), 2 cases of mantle cell lymphoma (MCL), 4 cases of follicular lymphoma (FL), 17 cases of diffuse large B lymphoma (DLBL) and 6 cases of lymphoblastic lymphoma. Histopathology diagnosis was available in 31 cases of NHL out of which there were 14 recurrent and 17 cases of primary NHL. Out of 15 DLBL cases diagnosed on FCI and FNAC, histology confirmed 14 cases and one of these cases was diagnosed as Burkitt's lymphoma on histology. Cases of FL (4), SLL (3) and MCL (2) were well correlated with histopathology. Out of the five cases suggestive of NHL on cytology, histopathology was available in four cases. Histology diagnosis was given as DLBL (1), SLL (1), anaplastic large cell lymphoma (1) and FL transformed into large cell NHL (1). Considering histopathology as gold standard, diagnostic specificity of combined FNAC and FCI was 100% (31/31) and sensitivity in sub-classification was 83.8% (26/31).

Conclusion

FNAC combined with FCI may be helpful in accurately sub-classifying NHL according to WHO classification. Many of the subtypes of NHL such as FL and MCL which were previously recognized as a pure morphologic entity can be diagnosed by combined use of FNAC and FCI. Other ancillary investigations such as chromosomal changes, cell proliferation markers etc. may be helpful in this aspect.