Comparison of lymphoid neoplasm classification. A blinded study between a community and an academic setting

Haematological cancers: improving outcomes. A summary of updated NICE service guidance in relation to Specialist Integrated Haematological Malignancy Diagnostic Services (SIHMDS)

Haematological malignancies are a diverse group of cancers that affect the blood, bone marrow and lymphatic systems. Laboratory diagnosis of haematological malignancies is dependent on combining several technologies, including morphology, immunophenotyping, cytogenetics and molecular genetics correlated clinical details and classification according to the current WHO guidelines. The concept of the Specialised Integrated Haematological Malignancy Diagnostic Services (SIHMDS) has evolved since the UK National Institute for Health and Care Excellence (NICE) Improving Outcomes Guidance (IOG) in 2003 and subsequently various models of delivery have been established. As part of the 2016 update to the NICE IOG, these models were systematically evaluated and recommendations produced to form the basis for quality standards for future development of SIHMDS. We provide a summary of the systematic review and recommendations. Although the recommendations pertain to the UK National Health Service (NHS), they have relevance to the modern delivery of diagnostic services internationally.

30 years of lymph node pathology: biomarkers and other advances

Over the last 30 years there has been a massive change in both the clinical and pathologic aspects of malignant lymphomas. Pathologists are now able to evaluate cellular phenotypes and lineages of tumor cells using a wide variety of biomarkers and molecular techniques. The ability to identify tumor cell phenotypes has revolutionized the classification of lymphomas, leading to an internationally agreed system based on the reliable recognition of specific clinico-pathologic entities. The World Health Organization classification combines clinical features, histomorphology, immunohistochemistry, and molecular and genetic marker data to precisely categorize lymphomas. On the clinical front the increasing use of needle core biopsies has made it easier and quicker to obtain tissue samples, and the development of (18)F-fluorodeoxyglucose positron emission tomography has revolutionized the assessment of patients both at presentation and after treatment. To improve overall outcomes for lymphoma patients there have been advances in the UK organization of cancer services. Cancer networks have been established, often with network multidisciplinary team meetings, and new diagnoses of lymphoma are reviewed on a network basis by pathologists specializing in the field. National and supranational quality control systems are in place for immunohistochemistry and for molecular techniques and multicenter clinical trials provide information about the efficacy of treatment regimens. The outcome of these advances is that a patient presenting in 2012 with suspected lymphoma can expect to be biopsied rapidly, to receive an accurate pathologic diagnosis by an expert hematopathologist, which will include prognostic marker information, and to have comprehensive disease assessment and discussion by a multidisciplinary team before embarking on the most appropriate treatment for his or her clinical situation.

Importance of Expert Central Review in the Diagnosis of Lymphoid Malignancies in a Regional Cancer Network

Purpose

The accurate diagnosis of hematologic malignancies remains a challenging area for histopathologists. In 2003, the North Central London Lymphoma network was established to provide a centralized expert review service for general histopathologists based in peripheral nonspecialist hospitals. By studying samples sent for review, we sought to assess the diagnostic and clinical impact of centralized expert review in lymphoma diagnosis.

Methods

A total of 1,949 patient samples were subject to expert review between 2003 and 2008. Diagnostic discordance rates were identified after expert review, and the impact on patient management was assessed by a hematologic oncology specialist.

Results

An overall discordance rate of 27.3% was identified. Among the 10 most commonly referred lymphoid malignancies, the discordance rate varied between 3.6% and 34.1%. A small but significant number of reactive (n = 17) and malignant (n = 5) discordant diagnoses were also identified. Expert central review resulted in a major change to patient management in 2.1% of patients and prevented delays in treatment in 9.3% of patients. During the 6-year study, the discordance rate improved significantly, decreasing from 32% to 13%. Although centralized review incurred additional costs, these were relatively small compared with the costs associated with treatment.

Conclusion

This retrospective study demonstrates the importance of expert central review in the accurate diagnosis and timely management of lymphoid malignancies. Furthermore, it shows that where full centralization of services is not viable, a network comprising nonspecialist hospitals linked to a center providing expert review is a practical alternative to full unification of services at a single location and can help prevent local deskilling.

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.

WHO non-Hodgkin's lymphoma classification by criterion-based report review followed by targeted pathology review: an effective strategy for epidemiology studies

In a previous criterion-based pathology report review of 717 cases of non-Hodgkin's lymphoma in an Australian population-based epidemiologic study, a WHO category could be assigned in 91% of cases, but confidence in this classification was high in only 57.5%. Given this lack of confidence, a pathology review was done in a subset of 315 cases, with the aims of assigning a WHO classification category and the corresponding International Classification of Diseases for Oncology, Third Edition code in all cases previously unclassified or classified with low confidence and testing the accuracy of report review in assigning a confident WHO classification. After pathology review, 10 cases were ineligible (not non-Hodgkin's lymphoma, 3.2%) and 99% (301 of 305) of the remainder were assigned a WHO classification, with high confidence in 87% (261 of 301). There was 78% overall agreement between the WHO classification assigned by report review and pathology review, with 92% agreement when there was high confidence in the report review classification and 69% agreement when there was low confidence. Eighteen percent of follicular lymphomas and 23% of diffuse large B-cell lymphomas were reclassified. The pathology review increased the accuracy of WHO classification by an estimated 12.5% in the 694 cases who were still eligible in the study. Although a potential error rate of 7.5% remained, reviewing more cases, or not reviewing any cases classified with high confidence, would have produced only a small change in accuracy. Criterion-based pathology report review of all cases followed by selective pathology review in cases classified with low confidence is recommended as a cost-saving and accurate strategy for pathology review in large epidemiologic studies.

Use of the WHO lymphoma classification in a population-based epidemiological study

BACKGROUND

Non-Hodgkin's lymphoma (NHL) is pathologically diverse. Epidemiological investigations into its increasing incidence and aetiology require accurate subtype classification.

PATIENTS AND METHODS

Available pathology reports of 717 cases aged from 20 to 74 years in an Australian, population-based epidemiological study of NHL were reviewed by one anatomical pathologist to assign a World Health Organization (WHO) classification category. High or low confidence was assigned to the diagnosis of NHL, cell phenotype and WHO category and reasons given for low confidence.

RESULTS

The most informative biopsy reports were from open tissue biopsy (79% of cases), tissue core biopsy (8%), cytology (4%) and bone marrow (9%); 8% of cases had inadequate biopsies for diagnostic purposes. Immunohistochemistry or flow cytometry reports were available for 96% of cases, gene rearrangement studies for 6% and cytogenetics for 3%. The reviewer assigned high confidence to the diagnosis of NHL in 93% of cases and also the phenotype in 88%. While a WHO classification could be assigned in 91% of cases, confidence was high in only 57.5%; insufficient immunophenotyping was the commonest reason for low confidence.

CONCLUSIONS

Expert pathology review of a population-based sample of NHL can provide a WHO classification category for most cases. A high level of confidence in the classification, however, would require review of diagnostic material and additional phenotyping.

Analysis of 1983 cases of malignant lymphoma in Thailand according to the World Health Organization classification

Studying a large series of malignant lymphoma is important to increasing our understanding of this disease. Based on the World Health Organization classification system, 1983 cases of lymphoma at Siriraj Hospital were classified as either non-Hodgkin lymphoma (NHL) (92.1%) or Hodgkin lymphoma (HL) (7.9%). The NHL cases were 75% B cell type and 25% T cell type. Diffuse large B-cell lymphoma, unspecified peripheral T-cell lymphoma, follicular lymphoma, extranodal marginal zone B-cell lymphoma, precursor T lymphoblastic lymphoma, and Burkitt lymphoma accounted for 84.3% of all NHL cases found. Mixed cellularity and nodular sclerosis types constituted 77.7% of the HL cases found. An overall male preponderance was observed, but sex distribution differed among various types of lymphoma, and a female preponderance was observed in the elderly subjects. Changes in the frequency of B-cell NHL by age were characteristic: <50% in the first decade of life, a further decrease in the second decade, >60% in the third decade, and increases thereafter, reaching 90% after the seventh decade. High frequency of follicular lymphoma in Bangkok but low frequency in the Northeastern region and high frequency of HL in the Southern region were significant (P <0.05). Extranodal involvement was observed in 58.7% of NHLs, commonly affecting the upper aerodigestive tract and gastrointestinal tract, with some differences in geographical distribution. Higher frequencies of T-cell NHLs involving extranodal sites and of B-cell NHLs involving lymph nodes were significant (P <0.05). The distribution of various types of lymphoma and comparison with other large series of lymphoma further demonstrates the heterogeneity of this disease.

The clinical impact of expert pathological review on lymphoma management: a regional experience

The All Wales Lymphoma Panel (AWLP) was established in January 1998 to provide a central expert pathological review service for district general hospital pathologists. A discordance rate of 20% between the submitted and reviewed diagnosis has previously been identified. It has not been known whether this change in diagnosis affects clinical management. Ninety-nine patients whose diagnosis was changed as a result of central pathological review are presented. Between January 1998 and August 2000, 125 of 745 (17%) specimens submitted for AWLP review had a consequent change in pathological diagnosis. Of these 125 specimens, 99 (79%) complete case notes were recovered. In all 99 cases, a hypothetical management plan was generated using collected data, clinical protocols and the submitted pathological diagnosis. These plans were compared with the actual management patients received based on the reviewed diagnosis proffered by the AWLP. Forty-six of 99 (46%) cases had a change in management as a result of central pathological review. Overall, management was changed in 8% of cases referred for central pathological review. In conclusion, expert central pathological review has a direct effect on patient management.