Acute myeloid leukemia: immunohistologic findings in paraffin-embedded bone marrow biopsy specimens

Factors Affecting Early Death and Survival of Patients With Acute Promyelocytic Leukemia Treated With ATRA-Based Therapy Regimens

PURPOSE

To perform a retrospective analysis of the prognostic relevance of clinicopathologic parameters in a well-documented cohort of patients treated with all-trans-retinoic acid (ATRA)-based induction regimens in order to discover which indicators can predict a high risk of early death (ED) and patient survival.

PATIENTS AND METHODS

We analyzed data of 288 newly diagnosed adult acute promyelocytic leukemia patients in Hangzhou, China. The median follow-up time was 32 months (range, 6-78 months).

RESULTS

The 3-year disease-free and overall survival rates were 90.83% and 91.69%, respectively. In the multivariable analysis, older age (≥ 60 years) was the only independent risk factor for ED (hazard ratio [HR] = 15.057; P = .004). High white blood cell count was not a risk factor for ED (P = .055), but it was for relapse (HR = 2.7; P = .009). FLT3 mutation (HR = 3.9; 95% confidence interval, 1.4 to 10; P = .007) and older age (≥ 60 years) (HR = 5.3; 95% confidence interval, 2.4 to 11; P < .001) were prognostic factors for poorer disease-free and overall survival. Interestingly, CD15 negativity (HR = 0.23; P = .049) was a prognostic factor for relapse. The ED rate was 5.9% (17/288 patients).

CONCLUSION

The perceived impact of the identification of these high-risk factors should be described in order to decide whether any modifications to treatment strategy should be entertained.

Acute leukemia immunohistochemistry: a systematic diagnostic approach

CONTEXT

The diagnosis and classification of leukemia is becoming increasingly complex. Current classification schemes incorporate morphologic features, immunophenotype, molecular genetics, and clinical data to specifically categorize leukemias into various subtypes. Although sophisticated methodologies are frequently used to detect characteristic features conferring diagnostic, prognostic, or therapeutic implications, a thorough microscopic examination remains essential to the pathologic evaluation. Detailed blast immunophenotyping can be performed with lineage- and maturation-specific markers. Although no one marker is pathognomonic for one malignancy, a well-chosen panel of antibodies can efficiently aid the diagnosis and classification of acute leukemias.

OBJECTIVE

To review important developments from recent and historical literature. General immunohistochemical staining patterns of the most commonly encountered lymphoid and myeloid leukemias are emphasized. The goal is to discuss the immunostaining of acute leukemias when flow cytometry and genetic studies are not available.

DATA SOURCES

A comprehensive review was performed of the relevant literature indexed in PubMed (National Library of Medicine) and referenced medical texts. Additional references were identified in the reviewed manuscripts.

CONCLUSIONS

Immunophenotyping of blasts using an immunohistochemical approach to lymphoid and myeloid malignancies is presented. Initial and subsequent additional antibody panels are suggested to confirm or exclude each possibility in the differential diagnosis and a general strategy for diagnostic evaluation is discussed. Although the use of immunohistochemistry alone is limited and evaluation by flow cytometry and genetic studies is highly recommended, unavoidable situations requiring analysis of formalin-fixed tissue specimens arise. When performed in an optimized laboratory and combined with a careful morphologic examination, the immunohistochemical approach represents a useful laboratory tool for classifying various leukemias.

Giant cell tumor of the extrahepatic biliary tree: a clinicopathologic study of 4 cases and comparison with anaplastic spindle and giant cell carcinoma with osteoclast-like giant cells

We report four previously undescribed primary giant cell tumors of the extrahepatic biliary tree and morphologically compare them with 10 anaplastic spindle and giant cell carcinomas with osteoclast-like giant cells of the gallbladder. Two giant cell tumors were located in the distal common bile duct; one in the cystic duct and one in the gallbladder. The 3 patients with bile duct tumors were male, and the only patient with a gallbladder tumor was a female. The age of the patients ranged from 45 to 60 years with an average of 55 years. The patients with bile duct tumors presented with biliary obstruction, and the patient with a gallbladder tumor presented with symptoms of cholelithiasis and a gallbladder mass. Histologically, the tumors were similar to giant cell tumors of bone. They consisted of a mixture of mononuclear and multinucleated osteoclast-like giant cells. The mononuclear cells showed no atypical features, and their nuclei were similar to those of the multinucleated giant cells. CD163 immunoreactivity was restricted to the mononuclear cells, whereas CD68 and HAM 56 labeled only the multinucleated osteoclast-like giant cells. The mononuclear cells were EMA-positive but did not express cytokeratins. Follow-up showed that 3 patients were alive and disease-free 3.7 to 7 years after surgery. The anaplastic spindle and giant cell carcinomas contained a fewer number of osteoclast-like giant cells, and their mononuclear cells showed considerable variation in size and shape, marked cytologic atypia, and numerous mitotic figures. They were focally cytokeratin positive (AE1/AE3; CAM 5.2) and did not label with CD163, CD68, and HAM 56. The benign osteoclast-like giant cells showed immunoreactivity for CD68 and HAM 56 but were negative for CD163 and cytokeratins. Giant cell tumors of the extrahepatic biliary tree are benign true histiocytic neoplasms that should be distinguished from the highly lethal anaplastic spindle and giant cell carcinomas with osteoclast-like giant cells by detailed cytologic analysis and immunohistochemical stains for CD163, CD68, HAM 56, and cytokeratins.

Natural feline coronavirus infection: differences in cytokine patterns in association with the outcome of infection

Natural and experimental feline coronavirus (FCoV) infection leads to systemic viral spread via monocyte-associated viraemia and induces systemic proliferation of monocytes/macrophages. In the majority of naturally infected animals, FCoV infection remains subclinical and is associated with generalised B and T cell hyperplasia, but no other pathological findings. A minority of cats, however, develop feline infectious peritonitis (FIP), a fatal systemic granulomatous disease. This is generally accompanied by B and T cell depletion. The obvious functional differences of lymphatic tissues in FCoV-infected cats with and without FIP suggest that they contribute to the outcome of FCoV infection. This study attempted to evaluate the functional changes in haemolymphatic tissues after natural FCoV infection, with special emphasis on the magnitude, phenotype and function of the monocyte/macrophage population. The spleen, mesenteric lymph nodes and bone marrow from naturally FCoV-infected cats with and without FIP and specific pathogen-free (SPF) control cats were examined for the quantity and activation state of monocytes/macrophages both by immunohistology and by quantitative real time PCR for the transcription of interleukin (IL)-1β, IL-6, IL-10, IL-12 p40, tumour necrosis factor (TNF), granulocyte colony stimulating factor (G-CSF), macrophage-CSF (M-CSF) and GM-CSF. Compared to cats with FIP, FCoV-infected cats without FIP exhibited significantly higher IL-10 levels in the spleen and significantly lower levels of IL-6, G- and M-CSF in mesenteric lymph nodes. In cats with FIP, however, IL-12 p40 levels were significantly lower in lymphatic tissues in comparison to both SPF cats and FCoV-infected cats without FIP. In comparison to SPF cats, FIP cats had significantly higher IL-1β levels and lower TNF levels in mesenteric lymph nodes and lower M-CSF levels in the spleen. Findings indicate that FCoV-infected cats which do not develop FIP are able to mount an effective FCoV-specific immune response and can avoid excessive macrophage activation and FIP, possibly by upregulation of IL-10 production. Development of FIP, however, might be due to a lack of IL-12 which inhibits an effective cellular immune response and allows for monocyte/macrophage activation and the development of FIP.

Applications of Flow Cytometry and Immunohistochemistry to Diagnostic Hematopathology

Objective.—Diagnostic hematopathology depends on the applications of flow cytometric immunophenotyping and immunohistochemical immunophenotyping combined with the cytomorphology and histologic features of each case. Select cases may require additional ancillary cytogenetic and molecular studies for diagnosis. The purpose of this review is to focus on the applications of flow cytometric and immunohistochemical immunophenotyping of paraffin-embedded tissue to diagnostic hematopathology. Advantages and disadvantages of these techniques are examined.

Data Sources.—The literature is extensively reviewed (PubMed 1985–2003) with an emphasis on the most recent applications and those that are most useful clinically, both diagnostically and prognostically.

Study Selection.—Studies were selected based on statistically significant results in large studies with reported adequate clinical follow-up.

Data Extraction.—The methodology was reviewed in the selected studies to ensure reliable comparison of reported data.

Data Synthesis.—Flow cytometric immunophenotyping offers the sensitive detection of antigens for which antibodies may not be available for paraffin immunohistochemical immunophenotyping. However, paraffin immunohistochemical immunophenotyping offers preservation of architecture and evaluation of expression of some proteins, which may not be available by flow cytometric immunophenotyping. These techniques should be used as complimentary tools in diagnostic hematopathology.

Conclusions.—There are extensive applications of flow cytometric and immunohistochemical immunophenotyping to diagnostic hematopathology. As cytogenetic and molecular findings evolve in diagnostic hematopathology, there may be additional applications of flow cytometric and immunohistochemical immunophenotyping to this field of pathology.

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.

Evaluation of bone marrow specimens with acute myelogenous leukemia for CD34, CD15, CD117, and myeloperoxidase

CONTEXT

Immunophenotyping of bone marrow (BM) specimens with acute myelogenous leukemia (AML) may be performed by flow cytometric (FC) or immunohistochemical (IH) techniques. Some markers (CD34, CD15, and CD117) are available for both techniques. Myeloperoxidase (MPO) analysis may be performed by enzyme cytochemical (EC) or IH techniques.

OBJECTIVE

To determine the reliability of these markers and MPO by these techniques, we designed a study to compare the results of analyses of these markers and MPO by FC (CD34, CD15, and CD117), EC (MPO), and IH (CD34, CD15, CD117, and MPO) techniques.

MATERIALS AND METHODS

Twenty-nine AMLs formed the basis of the study. These AMLs all had been immunophenotyped previously by FC analysis; 27 also had had EC analysis performed. Of the AMLs, 29 had BM core biopsies and 26 had BM clots that could be evaluated. The paraffin blocks of the 29 BM core biopsies and 26 BM clots were stained for CD34, CD117, MPO, and CD15. These results were compared with results by FC analysis (CD34, CD15, and CD117) and EC analysis (MPO).

RESULTS

Immunodetection of CD34 expression in AML had a similar sensitivity by FC and IH techniques. Immunodetection of CD15 and CD117 had a higher sensitivity by FC analysis than by IH analysis. Detection of MPO by IH analysis was more sensitive than by EC analysis. There was no correlation of French-American-British (FAB) subtype of AML with CD34 or CD117 expression. Expression of CD15 was associated with AMLs with a monocytic component. Myeloperoxidase reactivity by IH analysis was observed in AMLs originally FAB subtyped as M0.

CONCLUSIONS

CD34 can be equally detected by FC and IH techniques. CD15 and CD117 are better detected by FC analysis and MPO is better detected by IH analysis.

Acute lymphoblastic leukaemia: correlation between morphological/immunohistochemical and molecular biological findings in bone marrow biopsy specimens

BACKGROUND

Although numerous antibodies suitable for use on paraffin wax embedded sections are available for the subtyping of acute leukaemia (acute myelogenous leukaemia (AML) and acute lymphoblastic leukaemia (ALL)) in bone marrow biopsy sections, unequivocal identification of the cell line involved is sometimes impossible.

METHODS

Forty eight formalin fixed, paraffin wax embedded bone marrow biopsy specimens that had been decalcified in EDTA were investigated, including 42 thought to exhibit ALL on the basis of bone marrow smears. Five specimens exhibited AML and one biphenotypic leukaemia, as diagnosed immunohistochemically in bone marrow biopsies. Immunostaining was performed with antibodies against relatively specific B and T cell antigens. The blasts were investigated for rearrangements of the immunoglobulin heavy chain (IgH) and the T cell antigen receptor (TCR) genes.

RESULTS

Amplifiable DNA was obtained from all 48 specimens. An IgH gene rearrangement was detected in 20 of 23 c-ALL specimens. Four of seven T cell ALL (T-ALL) specimens had a TCR-gamma gene rearrangement, and the one B cell ALL (B-ALL) specimen exhibited a clonal IgH gene. Three of four cases of unclassifiable ALL could be assigned to the B cell lineage on the basis of gene rearrangement analysis. Seven cases originally diagnosed in smears as ALL were rediagnosed as AML (n = 5) or biphenotypic leukaemia (n = 2) because of immunohistochemical reactivity for myeloperoxidase or lysozyme. Two of these AML cases and two of three cases of biphenotypic leukaemia exhibited a monoclonal IgH gene rearrangement.

CONCLUSIONS

Acute leukaemia can be subtyped in bone marrow sections with a limited panel of antibodies suitable for use on paraffin wax embedded sections (against CD3, CD10, CD20, CD79a, myeloperoxidase, and lysozyme). In patients with ALL and a diagnostically equivocal immunophenotype, gene rearrangement analysis might indicate whether the B or T cell lineage is involved.

Cerebrospinal fluid examination in a case of childhood orbital granulocytic sarcoma

The diagnosis of a case of childhood orbital granulocytic sarcoma, initially classified as a poorly-differentiated malignant tumor, was finally considered at the time of relapse following primary treatment with chemotherapy and local irradiation. At this time, systematic cerebrospinal fluid examination showed numerous blast cells with Auer rods, consistent with the diagnosis of meningeal acute myeloid leukemia of M2 type, and concomitant biopsy of the tumor indicated the diagnosis of chloroma. Reevaluation of the primary biopsy confirmed this diagnosis.

Assessment of the value of immunohistochemistry in the subtyping of acute leukemia on routinely processed bone marrow biopsy specimens with particular reference to macrophage-associated antibodies

The value of immunohistochemical staining in the subtyping of acute leukemia was investigated on 36 routinely processed (formalin-fixed and paraffin-embedded) trephine biopsy specimens from the iliac crest containing diffuse infiltrates of acute myelogenous leukemia (AML; n = 23) and acute lymphoblastic leukemia (ALL; n = 13). These were stained with a broad panel of antibodies (n = 23) against various leukocyte antigens, among them 11 macrophage-associated antibodies (MAAs): Ki-M1p, MAC387, HAM56, LN5, KP1 (CD68), PG-M1 (CD68), Ki-M4p, DAKO-DRC (CD35), and antibodies against lysozyme, alpha 1-antichymotrypsin, and S100 protein. The French-American-British (FAB) classification subtypes of the AML cases, as determined by enzyme-cytochemical and/or immunocytological investigation of bone marrow smears, were as follows: M1 = 6, M2 = 5, M4 = 7, M5 = 3, and AML (not classified) = 2. The 13 cases of ALL were classified as follows: c-ALL (pre-B-ALL) = 7, B-ALL = 3, T-ALL = 2, and ALL (not classified) = 1. All the MAAs except LN5, Ki-M4p, and DAKO-DRC stained blast cells in AML. However, the number of stained blast cells varied considerably within and between the individual subtypes (M4/5 > M2/1). Using Fisher's exact test a significant difference in frequency of blast cell staining between AML and ALL was found for four MAAs (anti-lysozyme, MAC387, Ki-M1p, and KP1) and two of the three myeloid cell markers applied (Ki-My2p and anti-neutrophil elastase). Of these six antibodies, the combination of anti-lysozyme and KP1 can be recommended for use in routine diagnostics for the differentiation of AML from ALL on the basis of immunohistochemical staining because both of these antibodies were found to stain a relatively large percentage of cases of AML but none of ALL. However, none of the MAAs were found to discriminate reliably between the FAB M4/5 and M1/2 subtypes of AML.

Bone marrow histology. 3: Value of bone marrow core biopsy in acute leukaemia, myelodysplastic syndromes, and chronic myeloid leukaemia

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Anti-CD34 immunoperoxidase staining in paraffin sections of acute leukemia: Comparison with flow cytometric immunophenotyping

Anti-CD34 is a monoclonal antibody that reacts with bone marrow progenitor cells and leukemic blasts, and is expressed on 30% to 50% of all acute leukemias. Detection of CD34 has previously been restricted to flow cytometric studies. To expand the utility of CD34, we immunostained 46 paraffin-embedded bone marrow specimens with acute leukemia; results were compared with flow cytometric studies. CD34 reactivity was also evaluated in nine chronic leukemia cases, 27 malignant lymphoma cases (Hodgkin's disease and non-Hodgkin's lymphoma), six normal bone marrow specimens, and three benign, hyperplastic lymph node specimens. All cases that were CD34 positive by flow cytometry (11 of 19 B-cell precursor acute lymphoblastic leukemia cases, one of six T-cell acute lymphoblastic leukemia cases, and seven of 21 acute myeloblastic leukemia cases) were also CD34 positive in paraffin sections. Both cell membrane and cytoplasmic staining was seen. The positivity percentage and fluorescence intensity by flow cytometry correlated with the estimated number of stained cells and the intensity of immunoperoxidase staining in 18 of 19 CD34-positive cases. The remaining bone marrow and lymph node cases studied were CD34 negative; prominent endothelial cell staining, however, was noted. This is the first report of anti-CD34 staining of acute leukemia in paraffin-embedded sections. In contrast to other monoclonal antibodies reactive in bone marrow paraffin sections with leukemia, anti-CD34 immunoperoxidase staining is limited to leukemic blasts and may provide useful diagnostic information when flow cytometric studies are not available.

Immunohistochemical evaluation of bone marrow lymphoid nodules in chronic myeloproliferative disorders

One hundred and seventy bone marrow biopsies from patients with chronic myeloproliferative disorders (CMPDs) were evaluated for the presence of lymphoid nodules (LNs) and were immunostained using a panel of monoclonal antibodies (UCHL1, 4KB5 and L26) recognizing different lymphocyte antigens. LNs were found in 35% of cases of idiopathic thrombocythaemia, 24.6% of myelofibrosis/osteomyelosclerosis, 18.2% of polycythaemia vera 12.1% of chronic myeloid leukaemia and 19.2% of borderline cases. Varying degrees of immunohistochemical positivity for the three antibodies tested were found. LNs were always made up of variable proportions of both T- and B-lymphocytes with a prevalence of T-cells. This latter observation suggests that bone marrow LNs in CMPDs could be an expression of reactivity.