Immunohistochemistry in bone marrow pathology: a useful adjunct for morphologic diagnosis

Patient characteristics and outcome of CD20-positive HIV-associated lymphoma: a single-center KwaZulu-Natal, South African hospital 12-year retrospective review

BACKGROUND

Due to the high prevalence of HIV, HIV-associated lymphoma (HAL) is a common malignancy in South Africa. However, there is a paucity of literature on HAL from this region. The objective of this study was to profile the clinical characteristics and outcome of CD20-positive HAL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), with or without rituximab (R), from a single center in KwaZulu -Natal, South Africa.

METHODS

Retrospective chart review of adult patients treated from 2006 to 2018 for HIV-associated CD20-positive lymphoma. The clinical characteristics, complete response (CR), and 2-year overall survival (OS) are described.

RESULTS

The analysis included 102 patients, 54% females, median age of 39 years, and median CD4 cell count of 196 cells/μL. Bone marrow involvement was noted in 5%. Eighty-six percent of the cohort received concomitant antiretroviral therapy and chemotherapy, 76% of the CHOP group, and 92% of the R-CHOP group. Overall, a CR was seen in 55% (95% CI 45%; 65%), with a 2-year OS of 59% (95% CI 50%, 69%). A CR was attained in 46% on CHOP and 64% on R-CHOP, with a 2-year disease-free survival (DFS) for CHOP of 42% and 50% for R-CHOP.

CONCLUSION

Although the clinical characteristics and laboratory findings are similar to other higher-income cohorts, there was a difference in gender and incidence of marrow involvement. The low incidence of marrow involvement has prompted more routine use of immunohistochemistry and flow cytometry in staging marrows of HAL locally. Further randomized studies are required for the establishment of locally validated, cost-effective treatment guidelines.

The Expressions of CD30 and CD123 of Mastocytosis in Taiwan

Mastocytosis is a rare disease with a low incidence in Asia-Pacific populations. CD30 and CD123 may have potential prognostic and therapeutic value, but the results are inconsistent. Because racial disparities may exist, we aim to evaluate the expressions of CD30 and CD123 in a series of mastocytosis cases in Taiwan. Twelve patients with systemic and 7 with cutaneous forms of mastocytosis were studied. The expressions of CD30 and CD123 were correlated with the clinical features of the patients. Eighty-three percent (10/12) of patients with systemic mastocytosis (SM) had an associated hematological neoplasm. Four of the SM patients had both "B" and "C" findings, and they had a median survival time of 0.9 months. CD30 expression was positive in 50% (6/12) of SM cases and 100% (6/6) of cutaneous mastocytosis cases. CD123 was expressed focally or weakly in only 2 SM-associated hematological neoplasm cases. The distribution of mastocytosis subtypes and the expression of CD30 and CD123 in Taiwan differed from those reported in North America and Europe. However, mastocytosis, especially indolent forms, is easily overlooked as its heterogeneous and nonspecific clinical manifestations. A high index of suspicion and improved diagnostic methods can be helpful.

In Situ Gene Expression in Native Cryofixed Bone Tissue

Bone is a very complex tissue that is constantly changing throughout the lifespan. The precise mechanism of bone regeneration remains poorly understood. Large bone defects can be caused by gunshot injury, trauma, accidents, congenital anomalies and tissue resection due to cancer. Therefore, understanding bone homeostasis and regeneration has considerable clinical and scientific importance in the development of bone therapy. Macrophages are well known innate immune cells secreting different combinations of cytokines and their role in bone regeneration during bone healing is essential. Here, we present a method to identify mRNA transcripts in cryosections of non-decalcified rat bone using in situ hybridization and hybridization chain reaction to explore gene expression in situ for better understanding the gene expression of the bone tissues.

Clinical impact of dysplastic changes in acquired aplastic anemia: A systematic study of bone marrow biopsies in children and adults

Aplastic anemia (AA) is a rare disorder characterized by suppression of bone marrow function, which can progress to myelodysplastic syndrome (MDS) or to acute myeloid leukemia (AML). To determine if there are characteristics in bone marrow biopsies in children and adults previously diagnosed with acquired AA, which could predict progression to MDS, we evaluated 118 hypocellular bone marrow biopsies from adults (76 patients) and children (42) diagnosed initially with acquired AA previously to any treatment. Histology was reviewed according to a detailed protocol including Bennett and Orazi criteria for hypocellular myelodysplastic syndrome (h-MDS) and Bauman et al. criteria for refractory cytopenia of childhood (RCC). Twelve patients (10.2%; 6 children and 6 adults) progressed to MDS after a median time of 56 months. Criteria described by Bennett and Orazi suggestive of h-MDS in bone marrow biopsies were detected in 16 cases (13.5%; 8 adults and 8 children), and none in patients that progressed to MDS/AML. Twenty adults' biopsies (26.3%) had the histological criteria used for the diagnosis of pediatric RCC, and none showed MDS/AML evolution. Ten children (23.8%) were reclassified morphologically as RCC, and only one progressed to MDS. In this population with acquired aplastic anemia (AAA), no histological/immunohistochemical (H/IHC) bone marrow findings could discriminate patients with higher risk for myeloid clonal progression, which questions the diagnosis of h-MDS/RCC based only on the finding of dysplasia in the cases without increased blasts and/or the characteristic genetic abnormalities.

Rapid in-situ hybridization and immunohistochemistry: a pilot comparative study of two rapid diagnostic techniques for establishing monoclonality in plasma cell dyscrasias

Background

Light chain restriction needs to be established on the paraffin embedded tissue in certain types of plasma cell dyscrasias when serum levels of monoclonal immunoglobulins and light chain assays in the urine and serum may be normal. Rapid-in-situ-hybridisation (RISH) is thought to be a superior to immunohistochemistry (IHC) for kappa and lambda staining due to brighter and crisp staining without any background.

Methods

Fifty cases were included in this pilot study. Serum light chain restriction status of the case was taken as gold standard. The results of standard IHC for kappa and lambda immunoglobulins on the bone marrow biopsy of these cases was compared with RISH performed by the two commercially available kits. The results of the two methods were compared for sensitivity, need to repeat the test and background staining.

Results

The study found that in IHC first run sensitivity was 58% which improved to 88% after the second run. For RISH the sensitivity was 100%.

Conclusion

Rapid-in-situ-hybridisation (RISH) is a superior technique to IHC for detecting kappa and lambda light chain in plasma cells. The test is as labour intensive and time consuming as the routine IHC but has no background staining with more bright and crisp staining quality.

Radiographic Enlargement of Mandibular Canal as an Extranodal Primary Non-Hodgkin's Lymphoma Early Sign in an Asymptomatic Patient

Non-Hodgkin's lymphoma (NHL) is a lymphoproliferative disorder, from a subgroup of heterogeneous hematologic malignancies; the term “extranodal” refers to malignant involvement of tissues other than lymph nodes, tonsils, spleen, pharyngeal lymphatic ring, or thymus. Only 0.6% of all NHL are at mandible alone, and it may involve the inferior alveolar canal. We describe a case of bilateral enlargement of the mandibular canal without symptomatology, which was shown in a panoramic radiograph and cone beam computed tomography in a rehabilitation routine exam, as an early sign of primary extranodal NHL.

How we do: optimizing bone marrow biopsy logistics for sign-out within 2 days

Since the introduction of fast diagnostic tracks in many areas of oncology, the traditional processing of bone marrow biopsies (BMB), requiring either resin embedding or lengthy fixation and decalcification, is due to an upgrade. Thanks to a growing number of new commercially available tissue processors, microwave-enhanced processing is becoming a standard tool in the pathology laboratory, allowing rapid fixation and decalcification of BMB with preserved morphology and antigens. In this short report, we describe the use of a commercially available EDTA-based decalcification fluid (USEDECALC, Medite, Orlando, USA) in combination with the LOGOS J (Milestone, Bergamo, Italy), a closed microwave-enhanced tissue processor, for overnight fixation, decalcification, and paraffin impregnation of the BMB. This allows next-day reporting without impaired morphology or immunohistochemistry, and even improved DNA quality of the BMB.

Dealing with bone marrow biopsies in the staging of classical Hodgkin lymphoma: an old issue revisited in the (18)F-fluorodeoxyglucose-positron emission tomography era

Bone marrow biopsy is recommended for staging of classical Hodgkin lymphoma. The aim of this study was to compare bone marrow evaluation by histology with that obtained by (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET). One hundred and three cases of Classical Hodgkin Lymphoma were reviewed. All patients were submitted to FDG-PET evaluation. Bone marrow biopsy results were compared with clinical data and FDG-PET results. Ninety-one cases had available bone marrow biopsies. Overall, there were 16 positive and one suspect case. In five cases, the FDG-PET scan was positive and biopsy was negative: 1/5 was found to correspond to a bone fracture, 3/5 showed marked reactive bone marrow changes and in 1/5 no explanation for the discrepancy was found. FDG-PET showed high sensitivity, supporting the idea that when it is negative, biopsy could be avoided. Care should be taken in patients with a positive FDG-PET, where confirmation by bone marrow biopsy should be recommended.

Histopathological and immunohistochemical evaluation of bone marrow biopsy in myelodysplastic syndromes

SUMMARY In myelodysplastic syndromes (MDS), bone marrow biopsy (BMB) is now considered part of a multidisciplinary approach to bone marrow (BM) examination that must include cytological and cytogenetic assessment, while flow-cytometry and molecular studies can provide additional useful information. Undervalued in the past, BM histology has recently grown in importance in terms of diagnosis (i.e., MDS with BM fibrosis, hypoplastic MDS) and prognostic assessment (i.e., clusters of CD34+ blasts). Thus, BM histology must be considered complementary and not overlapping with the results of the other methods of BM study. Moreover, in recent years, numerous clinico-pathological studies have evidentiated, codified and standardized a series of histopathological parameters that are now considered essential for an effective and clinically useful histomorphological evaluation of the BMB. The aim of this work is to describe the histopathological and immunohistochemical approach to BMB that the pathologists of the Lombard Hematological Network (Rete Ematologica Lombarda [REL]; Italy) are carrying out on a standardized and shared basis in MDS patients.

[B-cell neoplasms with plasmacellular and plasmablastic differentiation]

Plasma cell malignancies are tumors of terminally differentiated B-cells in which the neoplastic plasma cells are the dominant and proliferating tumor cell component. Plasma cell myeloma (PCM) is one of the most common hematological neoplasms and typically does not cause diagnostic problems. A morphologically and immunophenotypically detectable plasmacellular orplasmablastic differentiation is, however, commonly observed in a wide range of mature B-cell lymphomas. A confident separation of the distinct entities requires the integration of clinical and morphological findings as well as an adequate phenotyping of both the plasma cell and the B-cell component if present. Detection of lymphotropic viruses, specific translocations and novel molecular markers, such as the MYD88 L265P mutation occurring in the vast majority of lymphoplasmacytic lymphomas complement our diagnostic repertoire. In this review we describe the most commonly observed diagnostic problems in separating small B-cell lymphomas from PCM and high-grade B-cell non-Hodgkin lymphoma (B-NHL) with plasmablastic differentiation from extramedullary spread of aggressive PCM and provide helpful criteria for routine diagnostics.

Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, and Monoclonal B-Cell Lymphocytosis

Chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), and monoclonal B-cell lymphocytosis (MBL) are clonal proliferations of small, mature B cells. CLL and SLL are considered neoplastic, although they are indolent and many patients with these lymphomas never require treatment. Most MBL cases share immunophenotypic and genetic features with CLL and SLL but have a small burden of clonal cells. This review focuses on the pathologic features of CLL, SLL, and MBL and their differential diagnoses. Guidelines are provided to separate the entities from one another and to avoid pitfalls in distinguishing these entities from other lymphomas and from reactive lymphoid proliferations.

Immunohematopoietic stem cell transplantation in Cape Town: a ten-year outcome analysis in adults

BACKGROUND AND OBJECTIVES

Immunohematopoietic stem cell transplantation has curative potential in selected hematologic disorders. Stem cell transplantation was introduced into South Africa in 1970 as a structured experimental and clinical program. In this report, we summarize the demography and outcome by disease category, gender, and type of procedure in patients older than 18 years of age who were seen from April 1995 to December 2002.

PATIENTS AND METHODS

This retrospective analysis included 247 individuals over 18 years of age for whom complete data were available. These patients received grafts mostly from peripheral blood with the appropriate stem cell population recovered by apheresis.

RESULTS

Patient ages ranged from 20 to 65 years with a median age of 42 years. There were 101 females and 146 males. There were no withdrawals and 63% survived to the end of the study. At 96 months of follow-up, a stable plateau was reached for each disease category. Median survival was 3.3 years (n=6, 14.6%) for acute lymphoblastic anemia, 3.1 years (n=44, 18%) for acute myeloid leukemia, 2.8 years (n=47, 19%) for chronic granulocytic leukemia, 2.8 years (n=71, 29%) for lymphoma, 1.5 years (n=23, 9%) for myeloma, 1.43 years (n=10, 4%) for aplasia, and 1.4 years (n=38, 15%) for a miscellaneous group comprising less than 10 examples each. Multivariate analysis showed that only diagnosis and age had a significant impact on survival, but these two variables might be interrelated. There was no significant difference in outcome by source of graft.

CONCLUSION

The results confirm that procedures carried out in a properly constituted and dedicated unit, which meets established criteria and strictly observes treatment protocols, generate results comparable to those in a First World referral center. Low rates of transplant-related mortality, rejection and graft-versus-host disease are confirmed, but the benefits cannot be extrapolated outside of academically oriented and supervised facilities.

Mouse phenotyping

Model organisms like the mouse are important tools to learn more about gene function in man. Within the last 20 years many mutant mouse lines have been generated by different methods such as ENU mutagenesis, constitutive and conditional knock-out approaches, knock-down, introduction of human genes, and knock-in techniques, thus creating models which mimic human conditions. Due to pleiotropic effects, one gene may have different functions in different organ systems or time points during development. Therefore mutant mouse lines have to be phenotyped comprehensively in a highly standardized manner to enable the detection of phenotypes which might otherwise remain hidden. The German Mouse Clinic (GMC) has been established at the Helmholtz Zentrum München as a phenotyping platform with open access to the scientific community (www.mousclinic.de; [1]). The GMC is a member of the EUMODIC consortium which created the European standard workflow EMPReSSslim for the systemic phenotyping of mouse models (http://www.eumodic.org/[2]).

Lack of utility of CD20 immunohistochemistry in staging bone marrow biopsies for diffuse large B-cell lymphoma

The utility of CD20 immunohistochemistry in the evaluation of staging bone marrow biopsies of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients has not been extensively studied. We used 113 routinely processed bone marrow biopsies to study the extent and pattern of involvement by lymphoma and CD20 staining. Twelve (10.6%) of 113 cases had involvement by morphology, and 5 (41.7%) of these showed histologic discordance between the primary site and the bone marrow. All cases with morphologic evidence of bone marrow involvement showed staining for CD20. Four (3.5%) of 113 cases had non-neoplastic aggregates that stained for CD20. One case (0.9%) showed a small benign lymphoid aggregate by immunohistochemistry that was not evident by morphology. Our results demonstrate that CD20 staining did not detect any examples of bone marrow involvement by DLBCL that were not evident by morphology. We conclude that immunohistochemistry for CD20 adds no increase in the sensitivity of detection of bone marrow infiltration by DLBCL.

Bone marrow aspirate and biopsy: a pathologist's perspective. II. interpretation of the bone marrow aspirate and biopsy

Bone marrow examination has become increasingly important for the diagnosis and treatment of hematologic and other illnesses. Morphologic evaluation of the bone marrow aspirate and biopsy has recently been supplemented by increasingly sophisticated ancillary assays, including immunocytochemistry, cytogenetic analysis, flow cytometry, and molecular assays. With our rapidly expanding knowledge of the clinical and biologic diversity of leukemia and other hematologic neoplasms, and an increasing variety of therapeutic options, the bone marrow examination has became more critical for therapeutic monitoring and planning optimal therapy. Sensitive molecular techniques, in vitro drug sensitivity testing, and a number of other special assays are available to provide valuable data to assist these endeavors. Fortunately, improvements in bone marrow aspirate and needle technology has made the procurement of adequate specimens more reliable and efficient, while the use of conscious sedation has improved patient comfort. The procurement of bone marrow specimens was reviewed in the first part of this series. This paper specifically addresses the diagnostic interpretation of bone marrow specimens and the use of ancillary techniques.

Systemic first-line phenotyping

With the completion of the mouse genome sequence an essential task for biomedical sciences in the twenty-first century will be the generation and functional analysis of mouse models for every gene in the mammalian genome. More than 30,000 mutations in ES cells will be engineered and thousands of mouse disease models will become available over the coming years by the collaborative effort of the International Mouse Knockout Consortium. In order to realize the full value of the mouse models proper characterization, archiving and dissemination of mouse disease models to the research community have to be performed. Phenotyping centers (mouse clinics) provide the necessary capacity, broad expertise, equipment, and infrastructure to carry out large-scale systemic first-line phenotyping. Using the example of the German Mouse Clinic (GMC) we will introduce the reader to the different aspects of the organization of a mouse clinic and present selected methods used in first-line phenotyping.

Immunohistochemical evaluation of 95 bone marrow reactive plasmacytoses

We histologically and immunohistochemically studied 95 bone marrow (BM) reactive plasmacytoses. Ten biopsies from plasma cell myeloma (PCM) patients served as a control group. In addition, we studied 10 monoclonal gammopathy of undetermined significance (MGUS) cases. Histologically, plasmacytosis varied between 5% and 25% with an interstitial pattern of plasma cell (PC) distribution being characteristically displayed. Immunohistochemically, we did not find any CD56/NCAM nor cyclin D1 expression in all biopsies (95 of 95, 100%), not even a weak, doubtful one; PCs were all polyclonal and CD138 positive. On the contrary, myeloma-associated PCs showed monoclonality for kappa- or lambda- light chain and strong CD56/NCAM immunoreactivity (8 of 10, 80%); four of them were cyclin D1 positive. Osteoblasts exhibited similar CD56/NCAM expression in both groups. Our data confirm the diagnostic utility of CD56/NCAM in the phenotypic characterization of polyclonal plasma cells, suggesting an important role of this particular immunomarker in the BM trephine study of polyclonal versus neoplastic plasmacytic infiltrations.

Application of Immunohistochemistry in the Diagnosis of Non-Hodgkin and Hodgkin Lymphoma

Context.—Beginning with the immunologic classifications of Lukes and Collins and Kiel and culminating in the Revised European-American Lymphoma and World Health Organization classifications, the diagnosis of lymphoid tumors relies heavily on the determination of cell lineage, maturation, and function, based on antigen expression in addition to morphology and clinical features. Technologic advances in immunology, antibody production, genetic analysis, cloning, and the identification of new genes and proteins by microarray and proteomics have provided pathologists with many antibodies to use in routine diagnosis.

Objective.—To provide guidance to the practicing pathologist in the appropriate selection of an antibody panel for the diagnosis of lymphoma based on morphology and relevant clinical data and to avoid pitfalls in the interpretation of immunohistochemical data. Attention is given to some of the newer antibodies, particularly against transcription factors, that are diagnostically and prognostically useful.

Data Sources.—The information presented in this article is based on review of the literature using the OVID database (Ovid MEDLINE 1950 to present with daily update) and 20 years of experience in diagnostic hematopathology.

Conclusions.—Immunophenotyping is required for the diagnosis and classification of lymphoid malignancies. Many paraffin-reactive antibodies are available to the pathologist but most are not specific. To avoid diagnostic pitfalls, interpretation of marker studies must be based on a panel and knowledge of a particular antigen's expression in normal, reactive, and neoplastic conditions.

Histological analysis of bone

Bone is an important target tissue for alcohol. Moderate alcohol consumption may slow bone loss during aging, but alcohol consumption inhibits bone growth during adolescence, and alcohol abuse in adults is an important risk factor for osteoporosis. Various techniques have been applied for evaluating the impact of alcohol on bone, including densitometry for assessment of bone mass and density, computed tomography for evaluation of bone microarchitecture, serum biochemistry for measurement of markers of global bone resorption and formation, and histomorphometry for assessment of cellular activity. Of these methods, histomorphometry is the gold standard for assessing bone because it is the only method for the direct in situ analysis of bone cells and their activities. The procedures described in this chapter provide tools for the histomorphometric characterization of the effects of alcohol on cancellous and cortical bone growth and turnover. Specifically detailed are processes for embedding, cutting, staining, and evaluating histological bone specimens with a focus on rodent models.

Diagnosis and Classification of Malignant Lymphoma and Related Entities in the Bone Marrow Trephine Biopsy

The trephine bone marrow (BM) biopsy is an important diagnostic tool in patients with malignant lymphoma. BM examination can serve to establish or confirm a primary diagnosis of lymphoma or to determine the extent of disease dissemination for staging purposes. BM histology renders information which cannot be gained equally from aspirate material, such as spacial distribution and extent of infiltrates, BM cellularity and fibrosis. Furthermore, cytology including flow cytometric immunophenotyping can give false-negative results in BM involvement by lymphoma due to intralesional fibrosis. In addition to morphological examination, the availability of a broad panel of antibodies suitable for paraffin-embedded tissues, in conjunction with less damaging decalcification procedures, nowadays enables us to perform complete immunophenotyping on BM trephines and allows for classification of lymphoma infiltrates according to established algorithms. Molecular determination of clonality and interphase fluorescent in situ hybridization can be employed selectively to resolve difficult cases. This review describes important diagnostic features of malignant lymphoma in the BM, relevant differential diagnoses, and the proper use of ancillary techniques.

Optimal processing of bone marrow trephine biopsy: the Hammersmith Protocol

Specimens of bone marrow trephine biopsy (BMT) are transported and fixed in acetic acid-zinc-formalin fixative, decalcified in 10% formic acid-5% formaldehyde and processed with other specimens to paraffin-wax embedding. Sections, 1-microm-thick, are cut by experienced histotechnologists and used for haematoxylin and eosin, Giemsa, reticulin silver and other histological stains. Further, all immunohistochemical procedures used in the laboratory, including double immunostaining, can be used on these sections with no or minimal modifications. About 10,000 BMT specimens have been analysed using this procedure since 1997 and diseases involving the bone marrow have been classified successfully. More recently, standardised polymerase chain reaction-based analysis and mRNA in situ hybridisation studies have been conducted. Excellent morphology with good antigen, DNA and RNA preservation is offered by the Hammersmith Protocol.

Ultrasonic Decalcification Offers New Perspectives for Rapid FISH, DNA, and RT-PCR Analysis in Bone Marrow Trephines

The requisite analyses on bone marrow biopsies are increasing: Molecular analyses such as fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and reverse transcriptase (RT)-PCR are demanded in addition to morphology and immunohistochemistry to improve diagnostic accuracy. Moreover, analysis of certain molecular prognostic or predictive biomarkers is increasingly mandatory in the assessment of hematologic diseases. In some circumstances, only formalin fixed, bone-containing tissue is available for molecular analysis. Because various fixation and decalcification procedures can impair DNA and RNA quality, there is an urgent need for standardized decalcification protocols which allow FISH and PCR analysis. In this study we developed a routinely applicable decalcification protocol to optimize the molecular analysis method although preserving morphology and immunohistochemical results. Therefore, we compared 2 different approaches including ultrasonic decalcification versus nonultrasonic procedures and ethylenediaminetetraacetate-based reagents versus acid-based ones. In our hands, the combined use of ultrasound and ethylenediaminetetraacetate-based reagents permits successful interphase FISH, PCR, and RT-PCR analysis whereas concomitantly preserving morphology and antigeneicity.