Bone marrow manifestations of infections and systemic diseases observed in bone marrow trephine biopsy review

Autopsy-related histomorphological findings in neonatal sepsis: a narrative review

Neonatal sepsis is an important concern in the field of neonatology, contributing significantly to morbidity and mortality among newborns worldwide. Despite progress in medical care, the accurate diagnosis and comprehension of the pathological underpinnings of neonatal sepsis continue to present challenges. Conventional diagnostic autopsy (CDA) provides unique opportunities to gain insights into the histomorphological alterations associated with neonatal sepsis. There is a paucity of literature regarding autopsy-related histomorphological features in neonatal sepsis in various organs. This narrative review aims to glean data from published literature concerning autopsy-related histomorphological findings in neonatal sepsis, which would aid in understanding organ-related pathological changes and assisting pathologists in determining the exact cause of death.

A critical assessment of the diatom test of rib bone marrow as a supporting procedure in the case of drowning

Diatoms (Bacillariophyta), being single-celled photosynthetic organisms, are widely distributed in aquatic ecosystems around the globe. Their exoskeletons are resistant to most environmental factors as well as chemical reagents in laboratory settings. Moreover, the ornamentation featured on exoskeletons can be used to identify individual diatomaceous species. As a result, the detection of diatoms in the internal organs, and especially rib marrow, of corpses found in water can serve as an important tool for diagnosing drowning as the cause of death as long as passive postmortem penetration of diatoms into those organs is excluded. In the environmental experiments described in this paper, diatoms were detected in rib marrow only when contamination resulted from a mechanical breach of bone integrity and structure, irrespective of the residence time of bone material in the aquatic environment. Our research suggests that the presence of diatom in the rib marrow may be the gold standard in the diagnosis of drowning in the future. Our animal model research dispels one of the doubts, such as the possibility of passive penetration of diatoms into the bone marrow, which is still under discussion in the forensic medicine community.

Morphological Spectrum of Bone Marrow Aspirates in Infections: A Clinico-Hematological Analysis

Context

Bone marrow examination (BME) is an invaluable tool for cases with pyrexia of unknown origin and pancytopenia. However, it is under-utilized for diagnosing infectious etiology and there is a paucity of literature regarding its role in infective pathology.

Aims

This study aims to bring to light the role of BME in diagnosing infectious pathology.

Settings and Design

A retrospective study was carried out on bone marrow aspirates (BMAs) sent to the hematology department over the past 4 years. Clinical details, peripheral smears and BMA were retrieved from the records and analyzed.

Subjects and Methods

Leishman-stained peripheral smears and BMA were studied along with bone marrow biopsy wherever feasible.

Results

A total of 52 cases were studied. The most common clinical presentation was fever, clinical finding was splenomegaly and hematological finding was anemia. Based on the morphological findings in combination with clinical history, cases were categorized into-parasitic (26.9%), viral (23.1%), tubercular (11.5%), and nonspecific infections (38.5%). Parasites such as Leishmania donovani, microfilaria, plasmodium falciparum, and vivax were reported in 14/52 (27%) cases. Associated BMA findings were plasmacytosis, eosinophilia, reactive lymphocytosis, or dyserythopoiesis. In 38% (20/52) cases, no specific cause of infection was found in the bone marrow. These patients showed histiocytosis, hemophagocytosis, maturation arrest in myeloid lineage, relative myeloid hyperplasia, dysmyelopoiesis, toxic granulation/vacuolation in myeloid cells, lymphocytosis, increased plasma cells or monocytosis in marrow.

Conclusions

Increased histiocytes, hemophagocytosis, dysplastic changes, maturation arrest, relative myeloid hyperplasia or reactive plasmacytosis, lymphocytosis, and monocytosis are BMA features which must alert the pathologist towards an infectious disease process, a knowledge of these changes can help extend the scope of BME beyond hemato-lymphoid malignancies.

Two Cases of Hemophagocytic Lymphohistiocytosis Associated with Disseminated Histoplasmosis Presented with Transient Pancytopenia

Transient pancytopenia due to reactive bone marrow suppression often occurs in hemophagocytic lymphohistiocytosis (HLH), a syndrome resulting from excessive immune activation following a severe infection. We reported two cases with pancytopenia and disseminated histoplasmosis accompanied by HLH, initially suspected to be blood malignancies. Our first case documented the relevance between the improvement of pancytopenia and the clearance of Histoplasma capsulatum in serial bone marrow aspirations. The second case showed immense Histoplasma engulfment by the macrophage in relation to a severe clinical condition, followed by improvement of clinical symptoms in accordance with the recovery of pancytopenia. These two cases highlighted the importance of comprehensive and critical analysis for cases with concurrent pancytopenia and severe infection, since it may be that the pancytopenia underlies the severe infection or vice versa.

Bone marrow aspiration and biopsy: techniques and practice implications

Bone marrow aspiration and biopsy (BMAB) is a valuable diagnostic procedure commonly performed for evaluation of a wide spectrum of diseases including hematologic abnormalities, nonhematologic malignancies, metabolic abnormalities, and tumor treatment response such as chemotherapy and bone marrow transplantation, hematologic tumor staging, and suspected infection in patients with fever of unknown origin. This minimally invasive intervention offers excellent safety profile and a high diagnostic yield. Radiologists should be familiar with clinical implications of BMAB for patient care and be able to implement various technical armamentarium available to achieve a safe intervention while maximizing procedure yield.

Bone Marrow Aspiration/Biopsy in the Evaluation of Fever of Unknown Origin in Patients with AIDS

BACKGROUND

HIV can interrupt the normal development of bone marrow cell lines. Bone marrow aspiration/biopsy (BMA/B) has been described as a diagnostic tool in AIDS patients with fever of unknown origin (FUO). In this review, we aimed to study patients with AIDS who had undergone a BMA/B to investigate FUO and describe the pathologies diagnosed in the biopsy.

METHODS

Thirty-four BMA/B samples were collected from AIDS patients admitted for work-up of FUO to the infectious disease ward of a tertiary referral HIV center in Tehran, Iran, between September 2014 and September 2015. Data including age, sex, duration of disease, CD4 cell counts, hepatitis B (HBV) and C (HCV) coinfection, the primary presentation of AIDS, and the treatment history were retrieved and analyzed. Patients underwent BMA/B. An expert pathologist reviewed the BMA/B specimens.

RESULTS

The mean age of the patients was 37.5 years (range, 26-56), and 27 (79%) were men. Twenty-seven (79%) patients contracted HIV from injection drug use, and 7 (21%) via sexual transmission. Only 3 (9%) of the BMA/B examinations were normal. Hypocellular bone marrow was diagnosed in 22 (65%) patients. Other pathologies included granulomas in 6 (18%), hematologic malignancies in 2 (6%), and leishmaniasis Aspergillosis, each in 1 (3%) patient. Six (17%) of the specimens were found to have tuberculosis infections.

CONCLUSION

Hypocellular bone marrow was the most common pathology on BMA/B examinations, followed by the presence of granulomas. Tuberculosis, Aspergillosis, and Leishmaniasis the opportunistic infections diagnosed on BMA/B specimens. Our results support BMA/B as an appropriate diagnostic tool for early diagnosis of opportunistic infections and malignancies in AIDS. BMA/B is indispensable in the armament of diagnostic tools of the physicians managing AIDS patients.

Role of Bone Marrow Examination in the Evaluation of Infections: Clinico-Hematological Analysis in a Tertiary Care Centre

OBJECTIVE

Bone marrow examination (BME) is an important modality for investigation of case of pyrexia of unknown origin (PUO). However, its yield in the diagnosis of infections has not been extensively studied and its role has not been well established. The aim of the study was to investigate the usefulness of BME and to evaluate the etiological and clinico-hematological profile in cases of bone marrow infections.

MATERIAL AND METHOD

This was a retrospective study where bone marrow cases were retrieved and a review of bone marrow findings with an infectious etiology from July 2014 to June 2018 was done. Detailed history, clinical examination and hematological parameters at presentation were recorded. Clinico-hematological correlation using descriptive statistics was performed.

RESULTS

The study included 55 cases, on analysis of which the maximum number of infections were those of leishmaniasis accounting for 35%, followed by HIV (29%) and tuberculosis (15%). Other etiological agents included fungal infections (histoplasmosis and aspergillosis), Enteric fever, Scrub typhus, parvovirus, falciparum malaria and filariasis. The most common clinical presentation was fever (80%) and the most common clinical finding was splenomegaly (66%).

CONCLUSION

Bone marrow examination is an important diagnostic tool to delineate etiological diagnosis in infectious conditions, particularly those presenting with PUO. Moreover, it is particularly important if urgent diagnosis is required or if alternate diagnostic modalities have not revealed a reason for PUO.

Severe Bone Marrow Edema Among Patients Who Underwent Prior Marrow Stimulation Technique Is a Significant Predictor of Graft Failure After Autologous Chondrocyte Implantation

BACKGROUND

Autologous chondrocyte implantation (ACI) is a well-established cartilage repair procedure; however, numerous studies have shown higher ACI graft failure rates after prior marrow stimulation techniques (MSTs).

PURPOSE

To identify which factors may predict decreased graft survival after ACI among patients who underwent a prior MST. A secondary aim was to investigate the specificity of these predictors.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

In this review of prospectively collected data, the authors analyzed 38 patients who had failed prior MST surgery and subsequently underwent collagen-covered ACI (case group). The case group was divided into graft failure ACI (n = 8, 21%) and successful ACI (n = 30, 79%). Fourteen clinical variables were categorized and analyzed to determine predictors for failure of the ACI graft: age, body mass index, sex, defect characteristics (number, size, location, etiology, type), presence of kissing lesion, intraoperative presence of intralesional osteophyte, time between an MST and ACI, previous surgery, duration of the symptoms, and concomitant surgical procedure. Preoperative magnetic resonance imaging (MRI) was used to evaluate the severity of subchondral bone marrow edema (BME), graded I (absent) to IV (severe), and the presence of subchondral cyst, hypertrophic sclerosis, and intralesional osteophyte. The effects of these MRI findings on the graft survivor were also investigated. Concurrently, a control group without a prior MST was matched to investigate the specificity of the previously determined predictors. These patients were matched individually according to age, sex, body mass index, and outcome of the procedure (failure [n = 8] or successful [n = 30] per the case group).

RESULTS

In the case group, the presence of preoperative severe BME was significantly higher among patients with failed ACI as compared with patients with successful ACI (P < .001). In the control group, the presence of severe BME was not significantly different between the failure and successful groups (P = .747). The ACI graft failure rate among patients with a prior MST and preoperative grade IV BME was 83.7% at 5 years postoperatively, resulting in a significantly lower survival rate as compared with patients with a prior MST and without severe BME (5-year graft failure rate, 6.5%; P < .001). All the other parameters did not differ significantly.

CONCLUSION

After a prior MST, the presence of grade IV BME by MRI was a predictive factor for graft failure among patients who then underwent second-generation ACI.

Our approach to bone marrow biopsies in cytopenia

Unexplained cytopenia is one of the most common indications for performing trephine bone marrow (BM) biopsy (BMB). The histopathological examination in this regard must be seen in the broader context of a multimodal approach in order to reach an as entity-specific as possible diagnosis, considering medical history, physical examination, laboratory data, peripheral blood morphology, BM aspiration smear, flow cytometry results and, if indicated, cytogenetics and molecular genetics. The particular irreplaceability of the histopathological work-up and the expectations to the BMB lie especially in the detection of fibrosing and/or focal processes (e.g. localized islets of blasts) and disorders extrinsic to the BM such as e.g. metastases, thrombotic microangiopathies, granulomatous myelitides etc. We propose a systematic combined histopathological pattern-based and blood count-based approach that can be applied in such circumstances to achieve a precise diagnosis or, at least, a clinically useful differential diagnosis, particularly taking into consideration specific morphologic pitfalls and application of ancillary techniques. Constitutional BM failure syndromes will not be profoundly addressed.

Automated enumeration of lymphoid and plasma cells in bone marrow to establish normal reference ranges

Aims

The number of precursor and mature lymphoid cells and plasma cells in normal bone marrow trephine (BMT) biopsies throughout the human lifespan is unknown. Reference ranges have been established from aspirated marrow, but due to haemodilution errors, these do not accurately reflect the native marrow milieu. We aimed to define age-specific, normal reference ranges for lymphoid and plasma cells in BMT biopsy specimens using a combined immunophenotyping and digital enumeration approach.

Methods

Morphologically normal BMT biopsy specimens (n=483) were obtained from patients aged 1 month to 90 years of age. Immunohistochemistry was performed to identify lymphoid progenitors , T-lymphocytes (CD3), B-lymphocytes (CD20) and plasma cells (CD138 and MUM1). Positive cells were counted using digital enumeration software, and the percent positivity for each antigen was determined per case. Mean values were generated for specific age groups, and age-defined reference ranges were determined for each antigen using normalised data.

Results

A mean of 16 609 cells (range: 7210–34 097) were counted per biopsy. Infant marrows showed a predominance of immature lymphoid progenitors and B cells. With increasing age, an increase in mean T cell and plasma cell numbers were observed. The results showed the same trends to flow cytometry references for aspirate material although the absolute values differed.

Conclusions

Combined immunohistochemistry and automated enumeration gives an accurate, reproducible number of antigen-positive cells and has generated normal reference ranges for these cell types in BMT biopsies. The method and ranges we have established have the potential to be applied in routine clinical practice.

Contribution to diagnosis and treatment of bone marrow aspirate results in critically ill patients undergoing bone marrow aspiration: a retrospective study of 193 consecutive patients

Background

The purpose of the work was to assess the contribution to diagnosis and/or treatment (CDT) of bone marrow aspiration (BMA) in the critically ill patient.

Methods

The retrospective study included 193 patients. On the basis of BMA findings, contribution to diagnosis was defined by one of four previously unestablished diagnoses (maturation arrest of granulocyte precursors, hemophagocytic lymphohistiocytosis, hematological malignancy, marrow infiltration with cancer cells) and to treatment as the initiation or withdrawal of a specific treatment including the decision to forgo life-sustaining treatment (DFLST).

Results

A CDT of BMA was observed in 40/193 patients (20.7%). BMA contributed to diagnosis in 37 cases (granulocyte precursor maturation arrest, N = 10; hemophagocytic lymphohistiocytosis, N = 12; hematological malignancy, N = 15) and to treatment in 14, including three DFLSTs. In multivariate analysis, the factors associated with a CDT were hematological malignancy, cancer or non-malignant hematological abnormality known on admission, indication for BMA excluding isolated thrombocytopenia, higher pre-BMA HScore (calculated prior to BMA), and higher SOFA score with or without platelet-count SOFA subscore. In the 160 patients without hematological malignancy or cancer known on admission, non-malignant hematological abnormality known on admission, indication for BMA excluding isolated thrombocytopenia, higher pre-BMA HScore, and higher SOFA score calculated with or without platelet-count SOFA subscore were independently associated with a CDT of BMA.

Conclusion

BMA can have a significant CDT in ICU patients with or without a known hematological malignancy or cancer on admission. An HScore calculated before BMA can be a valuable tool for predicting a CDT of BMA.

Electronic supplementary material

The online version of this article (10.1186/s40560-017-0263-7) contains supplementary material, which is available to authorized users.

HIV infection presenting as bone marrow cryptococcosis

Disseminated cryptococcal infection is an uncommon initial manifestation in immunocompromised patients. We report a rare case of a 40-year-old female presenting with fever and burning epigastrium. Peripheral blood film revealed a leukoerythroblastic picture with thrombocytopenia. Bone marrow aspiration showed granulomas along with cryptococcal yeast forms. The ELISA test for detection of human immunodeficiency virus (HIV) antigen was positive. Disseminated cryptococcosis can develop as the first manifestation of HIV infection in previously healthy individuals and granulomas in such bone marrow aspiration smears are a valuable clue to an underlying opportunistic infection.

Clinical forms of canine visceral Leishmaniasis in naturally Leishmania infantum-infected dogs and related myelogram and hemogram changes

Hematological analysis has limited applications for disease diagnosis in Leishmania infantum–infected dogs, but it can be very important in evaluating the clinical forms of the disease and in understanding the evolution of canine visceral leishmaniasis (CVL) pathogenesis. Recently, we demonstrated that alterations in leucopoiesis and erythropoiesis are related to clinical status and bone marrow parasite density in dogs naturally infected by L. infantum. To further characterize these alterations, we evaluated the association between the hematological parameters in bone marrow and peripheral blood alterations in groups of L. infantum–infected dogs: asymptomatic I (AD-I: serum negative/PCR+), asymptomatic II (AD-II: serum positive), oligosymptomatic (OD), and symptomatic (SD). Results were compared with those from noninfected dogs (NID). The SD group was found to present a decrease in erythropoietic lineage with concomitant reductions in erythrocytes, hemoglobin, and hematocrit parameters, resulting in anemia. The SD group also had increased neutrophils and precursors and decreased band eosinophils and eosinophils, leading to peripheral blood leucopenia. In the AD-II group, lymphocytosis occurred in both the peripheral blood and the bone marrow compartments. The SD group exhibited lymphocytosis in the bone marrow, with lymphopenia in the peripheral blood. In contrast, the AD-I group, showed no significant changes suggestive of CVL, presenting normal counts in bone marrow and peripheral blood. Our results showed for the first time that important changes in hematopoiesis and hematological parameters occur during ongoing CVL in naturally infected dogs, mainly in symptomatic disease. Taken together, our results based on myelogram and hemogram parameters enable better understanding of the pathogenesis of the anemia, lymphocytosis, and lymphopenia, as well as the leucopenia (eosinopenia and monocytopenia), that contribute to CVL prognosis.

Detection of porcine circovirus type 2 and viral replication by in situ hybridization in primary lymphoid organs from naturally and experimentally infected pigs

Porcine circovirus type 2 (PCV2) infection is the cause of postweaning multisystemic wasting syndrome (PMWS). It has been speculated whether cell types permissive of replication are found in the primary lymphoid organs and whether infection of these tissues has an important role in the pathogenesis of PMWS. The aim of this study was to determine if primary lymphoid organ cells support viral replication during PCV2 infection. This was done by histopathological examination of thymus and bone marrow from pigs experimentally inoculated with PCV2 (n = 24), mock-infected pigs (n = 12), pigs naturally affected by PMWS (n = 33), and age-matched healthy control animals (n = 29). In situ hybridization (ISH) techniques were used to detect PCV2 nucleic acid irrespective of replicative status (complementary probe, CP) or to detect only the replicative form of the virus (replicative form probe, RFP). PCV2 was not detected in the experimentally PCV2-inoculated pigs or the control animals. Among the PMWS-affected pigs, 19 of 20 (95%) thymuses were positive for PCV2 by CP ISH, and 7 of 19 (37%) of these also supported viral replication. By CP ISH, PCV2 was detected in 16 of 33 (48%) bone marrow samples, and 5 of 16 (31%) of these also supported replication. The 2 ISH probes labeled the same cell types, which were histiocytes in both organs and lymphocytes in thymus. The RFP labeled fewer cells than the CP. Thus, PCV2 nucleic acids and replication were found in bone marrow and thymus of PMWS-affected pigs, but there was no evidence that primary lymphoid organ cells are major supporters of PCV2 replication.

Bone marrow necrosis related to paracoccidioidomycosis: the first eight cases identified at autopsy

AIMS

To report the first eight bone marrow necrosis (BMN) cases related to paracoccidioidomycosis (PCM) from patient autopsies with well-documented bone marrow (BM) histology and cytology.

METHODS AND RESULTS

A retrospective evaluation was performed on BM specimens from eight autopsied patients from Botucatu University Hospital with PCM-related BMN. Relevant BMN literature was searched and analysed.

CONCLUSIONS

All eight patients had acute PCM. Six had histological only (biopsies) and two cytological only (smears) specimens. Five biopsy specimens revealed severe and one mild coagulation patterned necrotic areas. Five had osteonecrosis. The cytological specimens also showed typical BMN patterns. Paracoccidioides brasiliensis yeast forms were visible within necrotic areas in all cases.

Hematological profile in pyrexia of unknown origin: role of bone marrow trephine biopsy vis-à-vis aspiration

BACKGROUND

Bone marrow examination, by aspiration and/or trephine biopsy, is an important procedure in arriving at a diagnosis for long-duration febrile illness. The role of trephine biopsy in immunocompromised host, especially HIV-positive patients, has been well studied in the literature. However, its utility in immunocompetent patients is still shrouded by controversy. Thus, the authors attempted to evaluate the utility of marrow aspirate vis-à-vis trephine biopsy in establishing a diagnosis in cases of pyrexia of unknown origin in immunocompetent individuals, along with an analysis of haematological alterations in these patients.

MATERIALS AND METHODS

Over a period of 8 years, 121 patients with pyrexia of unknown origin underwent both bone marrow aspiration and trephine biopsy as a part of diagnostic work-up. These cases were reviewed for their clinical data and hematological findings, including detailed morphological features in aspiration smears and trephine biopsies. Bone marrow aspiration and biopsy were compared for their diagnostic efficacy in these patients.

RESULTS

A wide age range (2-65 years) was noted with a slight male predominance (2 : 1). Anemia was the most common feature in peripheral blood findings, seen in 97.5% of patients. Bone marrow aspiration was diagnostic in only 16.5% of cases, which revealed leishmaniasis or pure red cell aplasia. Granulomas were infrequent in marrow aspiration smears, as only two cases (1.6%) showed ill defined epithelioid cell collections. Compared to this, trephine biopsy offered a diagnosis in 76% of the cases. Granulomas were a frequent finding in the trephine biopsy, being present in 70% of the cases included. Additional cases diagnosed on biopsy (over those diagnosed with aspiration smears) included lymphoma, tuberculosis, fungal infection, sarcoidosis and hypocellular marrow.

CONCLUSION

Bone marrow trephine biopsy is an important adjunct to aspiration in arriving at an aetiological diagnosis of patient with long-duration febrile illness, and should be routinely performed in such cases. The presence of granulomas in trephine biopsy increases the likelihood of an etiologic diagnosis in these patients.

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.

Toxoplasma gondii: effect of maternal infection in the development of lymphoid organs of BALB/c neonates

Toxoplasmosis is one of the worldwide parasitic zoonoses. Alterations in the lymphopoietic system are still poorly studied. We analyzed lymphoid organs of BALB/c mice neonates from Toxoplasma gondii-intraperitoneally-infected mothers on 19th day of gestation, with 30 tachyzoites of strain RH. Normal non-infected pregnant females were used as controls. At 7 days after birth, animals were classified as neonates from infected (NIM) and neonates from non-infected mothers (NNIM). Weight of the thymus and number of thymic cells in NIM were decreased, percentage of apoptosis was significantly increased. Decrease in lymphocytes and monocytes and an increase of plasma cells were observed in bone marrow of NIM. Peripheral blood of NIM showed an increase of monocytes and neutrophils and a decrease in lymphocytes. Infection of the mother during the last day of gestation provokes in the neonates changes in the lymphoid organs that could explain survival of 75% of them.

Reactive versus neoplastic bone marrow: problems and pitfalls

Examination of the bone marrow poses several unique challenges to the pathologist: it is a semisolid organ without helpful gross correlation, it exists in a dynamic state with the peripheral blood and other organs of the lymphohemopoietic system, and the diagnosis of diseases affecting bone marrow often depends heavily on ancillary special studies. The bone marrow examination ideally encompasses review of the bone marrow biopsy histology (with or without additional nondecalcified clot preparation material), bone marrow aspirate smear cytology, and the peripheral blood smear; optimal procurement and processing of these samples is critical in ensuring that a maximal level of diagnostic information can be extracted. The pathologist must be aware of the clinical context of the bone marrow and the results of ancillary tests, whether these are ordered by the pathologist or the clinician. A combination of excellent diagnostic samples, appropriate ancillary tests, and knowledge of the clinical context provides the best background to distinguish between the common reactive and neoplastic processes that involve the bone marrow and to avoid diagnostic pitfalls in making these distinctions.

Early effects of tocilizumab on bone and bone marrow lesions in a collagen-induced arthritis monkey model

To understand the contribution of IL-6/IL-6R to subchondral bone and bone marrow abnormality in RA patients and the effects of tocilizumab on those abnormalities, we evaluated early change in a collagen-induced arthritis (CIA) monkey model with or without a single administration of tocilizumab. Six CIA cynomolgus monkeys received tocilizumab and 3 CIA monkeys received vehicle only. Their interphalangeal joints were analyzed using HE, silver impregnation (SI), or immunohistochemistry (RANKL) staining. The number of osteoclasts increased in the arthritis control but was suppressed in the tocilizumab-treated animals. Osteoblast/stromal cells of the arthritis control monkeys were of monolayer, while in the tocilizumab-treated monkeys, the cells were multi-layer or differentiated osteoblasts, and the meshwork of the reticulum fibers showed recovery in the SI. Hematopoietic marrow was replaced by interstitial fluid and reticulum fibers were eliminated in the arthritic model but showed recovery in the tocilizumab-treated animals. RANKL showed overproduction with arthritis and suppressed with tocilizumab treatment. The evidence indicates that IL-6/IL-6R is involved in subchondral bone and bone marrow change in RA patients. Tocilizumab treatment recovered changes in the CIA monkeys as a result of the co-differentiation between the osteoclasts and the osteoblast/stramal cells, at least partially through the suppression of RANKL overproduction.

Infiltrative myelopathy by paracoccidioidomycosis. A review and report of nine cases with emphasis on bone marrow morphology

AIMS

To report nine additional well-defined cases with infiltrative myelopathy by paracoccidioidomycosis (PCM), to describe the specific lesions and infection-related stromal abnormalities, to review the literature on this type of involvement and to introduce a new cause of granulomatous lesions of bone marrow.

METHODS AND RESULTS

Different bone marrow specimens were studied (aspirated smears, aspirated clots, biopsy imprints and biopsies) from nine patients with acute or subacute forms of PCM known to have PCM infiltrative myelopathy.

CONCLUSIONS

The biopsy specimens were the best for demonstrating bone marrow involvement by PCM. The lesions varied from compact and focal granulomas with few fungal cells to numerous disseminated fungal cells within a loose granulomatous inflammatory reaction, with a continuum between these extremes suggesting a spectrum of immune response to the fungi. Other findings such as bone marrow fibrosis, parenchymal coagulative necrosis and bone necrosis were also observed in the affected areas.

Ancillary techniques in bone marrow pathology: molecular diagnostics on bone marrow trephine biopsies

Pathologic examination of trephine bone marrow (BM) biopsies plays a central role in the diagnosis and staging of haematological neoplasms and other disorders affecting haematopoiesis. Haematopathology has been profoundly influenced by the advent of molecular genetic techniques suitable for paraffin-embedded tissues, and certain applications, such as the determination of B- and T-cell clonality, belong to its standard diagnostic repertoire. Many of these molecular tests can be performed successfully with nucleic acids extracted from BM trephine biopsies, if some technical aspects specific to this template source such as various fixation and decalcification procedures are taken into consideration. The current indications for molecular BM diagnostics range from the confirmation of lymphoma involvement with gene rearrangement analysis, demonstration of tumor-specific translocations in lymphoid and chronic myeloproliferative disorders along to the detection of microorganisms or marrow involvement by soft tissue sarcomas. The availability of quantitative polymerase chain reaction techniques for the investigation of allelic imbalances and gene expression levels in paraffin-embedded material also open new avenues for research and advanced diagnostics. The molecular detection of minimal residual disease in haematological neoplasms, especially in the context of new treatment strategies, will provide future challenges. This article summarizes the current state of the art in molecular diagnostics applied to paraffin-embedded BM biopsies.

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

Pathomorphological examination of trephine biopsies of the bone marrow (BM) represents a standard method for the diagnosis and staging of hematologic neoplasms and other disorders involving the BM. The increasing knowledge about the genetic basis and biology of hematologic neoplasms, as well as the recently proposed WHO classification system, provide the framework for an accurate diagnosis. Although conventional morphology remains the gold standard for paraffin-embedded BM trephines, immunohistochemical stainings have become an integral part of the diagnostic workup. Antibodies suitable for paraffin sections are generally applicable to BM trephines, but modifications of staining protocols may be necessary due to the alternative fixatives and decalcification procedures used for BM biopsies. The indications for immunostainings range from confirmation and classification of lymphoma involvement, subclassification of acute leukemias, and estimating blast counts in myelodysplastic and myeloproliferative syndromes to characterization of BM involvement in nonhematologic neoplasms. Although subtyping of NHL in the BM is more difficult from the point of morphology, classification of the entities that frequently involve the BM, especially the small B-cell lymphomas, can easily be achieved with the help of immunohistochemistry. In this review, we try to summarize the current state of the art in BM immunohistochemistry for the diagnosis of hematologic disorders. Moreover, diagnostic algorithms and useful antibody panels are proposed for a rational and cost-effective approach.

A pathologist's perspective on bone marrow aspiration and biopsy: I. Performing a bone marrow examination

The bone marrow aspirate and biopsy is an important medical procedure for the diagnosis of hematologic malignancies and other diseases, and for the follow-up evaluation of patients undergoing chemotherapy, bone marrow transplantation, and other forms of medical therapy. During the procedure, liquid bone marrow is aspirated from the posterior iliac crest or sternum with a special needle, smeared on glass microscope slides by one of several techniques, and stained by the Wright-Giemsa or other techniques for micro-scopic examination. The bone marrow core biopsy is obtained from the posterior iliac crest with a Jamshidi or similar needle and processed in the same manner as other surgical specimens. Flow cytometric examination, cytochemical stains, cytogenetic and molecular analysis, and other diagnostic procedures can be performed on bone marrow aspirate material, while sections prepared from the bone marrow biopsy can be stained by the immunoperoxidase or other techniques. The bone marrow procedure can be performed with a minimum of discomfort to the patient if adequate local anesthesia is utilized. Pain, bleeding, and infection are rare complications of the bone marrow procedure performed at the posterior iliac crest, while death from cardiac tamponade has rarely occurred from the sternal bone marrow aspiration. The recent development of bone marrow biopsy needles with specially sharpened cutting edges and core-securing devices has reduced the discomfort of the procedure and improved the quality of the specimens obtained.

Bone marrow pathology in AIDS

Bone marrow morphology is frequently abnormal in patients with AIDS. In this study, we reviewed 97 bone marrow biopsies of AIDS patients performed between 1998 and 2000 in the Emílio Ribas Institute of Infectology, which is the reference department for HIV. Specific diagnoses were performed in 33 cases. Fungi were observed in eight cases. Five of them were Histoplasma capsulatum, two were Cryptococcus neoformans, and one probably Candida albicans. Acid-fast bacilli were observed in 12 bone marrow biopsies, three of which were diagnosed to have no mycobacteriosis clinically. Foci of necrosis with clusters of macrophages without any well-formed granuloma were observed in nine cases and well-formed granuloma in three cases. Lymphomatous infiltration was observed in four cases of non-Hodgkin's lymphoma and in two Hodgkin's diseases (mixed cellularity). Extensive necrosis of bone marrow was observed in one case of Burkitt's lymphoma. In conclusion, bone marrow biopsy should be performed to elucidate the etiology of cytopenias, secondary infections, and fever of undetermined origin in AIDS patients.

Bone marrow biopsy: interpretive guidelines for the surgical pathologist

Ideally, the bone marrow core biopsy should be reviewed with knowledge of the clinical history, complete blood count, and findings in the peripheral blood and bone marrow aspirate smears. However, for a variety of reasons, the pathologist may receive the core biopsy and aspirate clot section without all of this information. Although this approach is not optimal, a great deal of valuable information can be generated from these specimens. Over the past 20 years, there has been considerable progress in the fields of flow cytometric analysis, immunohistochemistry, and molecular diagnostic studies that can be performed on smears or extracted DNA from paraffin embedded tissue. These modalities have augmented and refined diagnostic criteria formerly ascertained by light microscopy, cytochemistry, and cytogenetics. This is particularly true of some myeloid and lymphoreticular neoplasms where a collaborative and multidisciplinary approach to the diagnosis has become necessary. Despite this growing complexity and dependence on newer methodologies, the traditional role of histopathology in evaluating the bone marrow biopsy remains as important as it has been in the past. In this review, we focus on contemporary practices and expectations for interpreting bone marrow biopsies and clot sections.