Ultrastructural Alterations of Megakaryocytes in Some Hematologic Disorders

Bone marrow and peripheral blood samples of patients affected by hematologic disorders involving the megakaryocytic line were examined at the electron microscope. While in idiopathic thrombocytopenic purpura the megakaryocytes appeared almost normal, in primary thrombocythemia there were various ultrastructural alterations interpreted as a counterpart of ineffective thrombocytopoiesis. In one patient with blastic chronic myeloid leukemia and in another with acute megakaryoblastic leukemia, the electron microscope study was very useful in the identification of immature megakaryocytes. In fact, analysis of various ultrastructural parameters allowed some blast cells to be attributed to the megakaryocytic series. Furthermore, platelet demarcation system abnormalities and alterations of the circulating thrombocytes confirm the hypothesis that there is a block in megakaryocytic maturation.

Plasma membranes purified from myeloid leukemia cells before and after differentiation. I. Characterization of spectrin-like proteins and increased association of actin

Two-step sucrose density gradient centrifugation was used to isolate the plasma membrane of a myeloid leukemia cell line (Ml). Calspectin (or fodrin) was identified in the Triton-insoluble fraction from the plasma membrane, and the molecular size and actin- and calmodulin-binding activity were studied. During differentiation of this cell line, which accompanied the induction of cell motility and phagocytic activity, the membrane-bound actin increased dramatically, whereas calspectin increased only slightly. Therefore, calspectin does not appear to have a major function in the increased binding of actin filaments to the plasma membrane, a requirement for the induction of cell motility.

Ultrastructural evaluation of periodate-reactive glycoconjugates in human leukaemia cells

Periodate-reactive glycoconjugates in human leukaemic cells were examined electron microscopically by the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method. Granules in ALL cells were classified into 4 types based on PA-TCH-SP staining features. Abnormal granules containing glycogen were observed only in children with treatment-resistant ALL. Cytoplasmic granules in leukaemic cells of patients with AML and acute monocytic leukaemia exhibited moderate reactivity. The distribution pattern of glycogen in the cytoplasm of leukaemic cells was classified into 3 types, one lacking glycogen, one containing small glycogen particles scattered throughout cytoplasm, and one showing clusters of glycogen particles. Cells with glycogen clusters were observed in ALL cells and in erythroblasts from patients with erythroleukaemia. PA-TCH-SP reactivity was detected in the rough endoplasmic reticulum in acute promyelocytic leukaemia but not in ALL or other types of AML. Megakaryoblasts in megakaryocytic crisis of chronic myelogenous leukaemia exhibited characteristic PA-TCH-SP reactivity similar to that of normal megakaryocytes.

Megakaryoblastic transformation of Ph positive chronic granulocytic leukemia

A case of well-documented and illustrated megakaryoblastic transformation in a patient with chronic granulocytic leukemia is presented. The salient features of this case were the presence of megakaryoblasts in the peripheral blood and bone marrow and characteristic cytochemical and electron microscopic findings. In addition, the authors observed an unusual, previously unreported, similarity of the abnormal platelets with those described in the Gray platelet syndrome. A literature review of the 13 previously described cases is included.

Scanning electron microscope cytochemistry of normal and leukaemic leukocytes

Backscattered Electron Imaging (BEI) is a particular technique which permits to study cytochemical reactions with the Scanning Electron Microscope (SEM). The BEI data pertaining to specific enzymatic activities can be directly correlated to the surface morphology of each individual cell. Leukocytes from 5 normal individuals, 14 patients with acute nonlymphoblastic leukaemia (ANLL), 7 patients with chronic myeloid leukaemia (CML) and 3 patients with acute lymphoblastic leukaemia (ALL) were studied for myeloperoxidase activity, acid phosphatase localization, silver staining of the nuclei and phagocytosis of iron carbonyl in the BEI mode of SEM. Some normal peripheral blood leukocytes which cannot be distinguished by their surface morphology alone were satisfactorily identified with the BEI technique. Leukaemic myeloid cells can be recognized in many cases because of their positive myeloperoxidase reaction, while monocytic elements can be characterized by the presence of surface ruffles, acid phosphatase activity and active phagocytosis. The usefulness of the BEI technique in identifying different blood cell types with the SEM and its possible application to the diagnosis of certain cases of leukaemia are discussed.

Immunologic, biochemical, and ultrastructural characterization of the leukemia cell in F344 rats

Immunologic, biochemical, and morphologic characteristics of the mononuclear cell from the leukemia of F344 rats were determined. The cells were morphologically similar to large granular lymphocytes (LGL). Surface marker analysis revealed Fc gamma receptors, no Fc gamma receptor or complement receptor activity, and an inability to spontaneously rosette guinea pig erythrocytes. Leukemia cells also had a surface immunoglobulin that hemagglutinated normal rat erythrocytes. The surface immunoglobulin and Fc gamma receptors dissociated from the cell after 2 hours of in vitro incubation, but Fc gamma receptor activity was reexpressed after 6 hours of in vitro incubation. Cells were capable of adherence to glass surfaces but had a low capacity for phagocytosis of latex beads. Cytochemical analysis revealed a consistent, strongly positive reaction for esterase that was sensitive to NaF. The cytochemical profile of the leukemia cell was similar to that described for LGL.

Eosinophilic myelocytoma in an owl monkey (Aotus trivirgatus)

A mass found in the anterior mediastinum at necropsy of an adult female owl monkey (Aotus trivirgatus) was morphologically consistent with an eosinophilic myelocytoma. Lymph nodes, kidneys, bone marrow, and other tissues were diffusely infiltrated by neoplastic cells. Intracellular and extracellular Charcot-Leyden crystals were present in the neoplasm.

Granulocytic sarcoma of the peritoneum

Granulocytic sarcoma is an unusual extramedullary tumor composed of immature cells of the myelogenous series; it usually occurs during the course of myelogenous leukemia. This paper presents a rare case of granulocytic sarcoma of the peritoneum, occurring without evidence of myelogenous leukemia in peripheral blood and bone marrow.

Cytogenetic analysis of leukaemic colonies from acute and chronic myelogenous leukaemia

We have utilized the blast cell assay of Buick et al. (1977) to grow and subsequently cytogenetically analyze cultured colony forming cells (CFUs) from patients with acute and chronic myelogenous leukaemia (AML, CML). Cytogenetic analysis of CFUs was successful in 30/36 cases (83%), a success rate similar to direct harvesting techniques. Identical clonal chromosomal abnormalities demonstrated by direct techniques were also observed in CFUs from AML and CML. Removal of T-precursor cells by E-rosetting prior to plating did not eliminate growth of karyotypically normal cells. The combination of morphologic and cytogenetic studies performed clearly established that the assay system supports the growth of leukaemic progenitors. Although both karyotypically normal and abnormal leukaemic colonies grew in this assay, growth of leukaemic colonies was much more likely if the plated cells were karyotypically abnormal (P = 0.010). Leukaemic colony growth was also more frequent if the tritiated thymidine labelling index (LI%) of plated cells was greater than or equal to 5% (P = 0.018). Leukaemic colonies were most likely (P = 0.018) to have been derived from plated cells with both abnormal karyotype and high LI% (greater than or equal to 5%). Cytogenetic analyses from cultured cells revealed only those karyotypic features found in the uncultured cells (i.e., no additional abnormal sublines were found). However, in most cases, the greatly enhanced number and quality of mitotic figures allowed for more detailed banding analysis.

Fibrous long spacing-like fibers in the bone marrow of myloproliferative disorder

Bone marrow obtained at autopsy from four cases of primary myelofibrosis and four cases of chronic myelogenous leukemia, was studied electron microscopically. In all the cases of primary myelofibrosis, the excess of collagen fibers in the bone marrow showed mostly about 2,000 A diameter and 1,000 A periodicity, i.e. fibrous long spacing (FLS)-like fibers. These FLS-like fibers were also seen in secondary myelofibrosis in three of the four cases of chronic myelogenous leukemia. These fibers were abundant around fibroblasts and small blood vessels. An apparent continuity between the dark bands of FLS-like fibers and the basement membrane material around small blood vessels was also revealed. Moreover, it was observed that these dark bands of FLS-like fibers contained acid mucopolysaccharides.

Ultrastructural characterization of de novo and secondary leukemias

Cells from 95 patients with acute leukemia were studied by cytochemistry, light microscopy, and transmission electron microscopy (TEM), and were classified according to the French-American-British (FAB) guidelines. This group included 63 patients with acute nonlymphocytic leukemia (ANLL) de novo, 18 with acute lymphocytic leukemia (ALL), and 14 with ANLL as a second malignancy. In addition, 13 cases of chronic myelocytic leukemia in blast crisis were studied. Ultrastructural examination resulted in reclassification of 6 cases of ANLL de novo; two of these were reclassified from M2 (myeloblastic leukemia with maturation) to M3 variant (microgranular variant of hypergranular promyelocytic leukemia). The classification of the cases of CML in blast crisis was identical by light microscopy and TEM. IN 1 case of myeloblastic crisis, however, basophilic granules were demonstrated by TEM but were not appreciated by light microscopy. Classification of the cases of secondary leukemia was possible by light microscopy and cytochemistry in all 14 cases, but was often difficult since the cytochemical reactions were usually less intense than in de novo ANLL. This was particularly true in those cases classified as M1, and in such cases, TEM was required to confirm the diagnosis.

Granulocytic sarcoma of the brain after renal transplantation

A case of granulocytic sarcoma of the brain in a renal transplant recipient treated with immunosuppressive agents is presented. While the increased risk of malignant lymphoma, particularly large-cell lymphoma (reticulum cell sarcoma, histiocytic lymphoma, immunoblastic sarcoma) in these patients is well known, this appears to be the first report of a granulocytic sarcoma. Granulocytic sarcoma, a rare tumor composed of immature granulocytic elements, almost never involves the parenchyma of the brain. Histochemical examination may be necessary to distinguish this lesion from other poorly-differentiated neoplasms.

Variations in the activity of nucleolar organizers in different tissues, demonstrated by silver staining of human normal and leukemic cells

A simple silver-staining technique that demonstrates those nucleolar organizing regions of metaphase chromosomes which are transcriptionally active during the preceding interphase (AgNORs) has been applied to cells obtained from the bone marrow and mitogen-stimulated peripheral blood lymphocyte cultures of hematologically normal individuals and patients with various forms of leukemia. In the majority of bone marrow cells from the normal controls and many of the patients, the number of cells with detectable AgNORs, and the staining intensities in those cells which were Ag+, were markedly reduced compared with the levels found in blood lymphocytes. The numbers of cells having satellite associations and the numbers of chromosomes participating in these associations also generally reflected the proportions of AgNORs present. When patterns of bone marrow silver staining were compared between patients with leukemia, distinct differences were found which could be correlated with cytology. It is suggested that different cell types have characteristic AgNOR staining profiles, reflecting specific regulation of ribosomal RNA synthesis in particular cell lineages. AgNOR staining may indicate, therefore, the predominant cell types that divide in the bone marrows of patients with different forms of leukemia.

3. The value of chromosome studies in the classification and management of the leukemias

Chromosome identification techniques have shown the non-random nature of cytogenetic changes in leukemia. In addition, they have identified structural chromosome abnormalities occurring in specific types of acute leukemia as classified by the FAB criteria. Such cytogenetic sub groups are associated with differing prognoses. In acute lymphocytic leukemia, even the ploidy of the leukemic cells appears important in predicting prognosis. Identification of the Philadelphia (Ph1) chromosome has diagnostic significance in chronic granulocytic leukemia. This makes possible the classification of patients into Ph1 + and Ph1 - varieties which have different responses to therapy. Similar variations are found between the 2 groups of patients who do or do not develop additional abnormalities with blastic transformation. The implication of these findings in both acute and chronic leukemia may influence choice of therapy in the future.

Granulocytic sarcoma (chloroma) initially seen as acute mastoiditis

Granulocytic sarcoma (chloroma) is a localized tumefaction of immature granulocytes that is typically seen in association with myelogenous leukemia. The primitive cell population seen in biopsy material may be misinterpreted as histiocytic lymphoma or other sarcoma unless additional studies are performed. We saw a 36-year-old woman with promyelocytic leukemia in remission who had the signs and symptoms of an acute coalescent mastoiditis. Histologic examination of the surgical specimen, however, demonstrated a granulocytic sarcoma. Our case exemplifies some of the difficulties that may be encountered in the diagnosis of granulocytic sarcoma and illustrates the point that symptoms of an inflammatory process in a patient with a diagnosis of leukemia must be regarded with a degree of suspicion.

Megakaryocyte cultures in the chronic phase and in the blast crisis of chronic myeloid leukaemia: studies on the differentiation of the megakaryocyte progenitors and on the maturation of megakaryocytes in vitro

Megakaryocyte (MK) colony formation has been studied in the chronic phase and in the blast crisis of chronic myeloid leukaemia (CML). Blood cells were grown in plasma clot for 13 d. MKs were subsequently identified by immunofluorescent techniques using two monoclonal antiplatelet antibodies (AN51 and J15). The maturation process was studied by ultrastructural methods. A marked increase in the number of circulating CFU-MK was observed in all the 10 cases studied prior to chemotherapy (70-fold increase per ml of blood). No significant modification in the regulation of MK colony formation as compared to that of normal subjects was observed. The predominant abnormality in maturation in culture was the occurrence of many hypoploid MKs (microMKs). However, the cytoplasmic maturation of the MKs was identical to that of normal subjects with occasional platelet shedding. Since microMKs predominated in some patients, scoring of MK colonies in CML necessitated immunofluorescent labelling to permit identification of MKs. During the blast crisis, MK colony formation occurred in four out of five patients with an extremely high plating efficiency in the case of promegakaryoblastic transformation. In contrast, MK colonies could not be grown from blood samples of patients with acute leukaemia, including two cases of promegakaryoblastic leukaemia. Maturation of MKs in blast crisis was identical to that of the chronic phase. Furthermore, after short periods of culture in liquid medium, circulating promegakaryoblasts from patients in blast crisis matured with the consequent production of alpha-granules and demarcation membranes. These results confirm the contention that CML represents a pluripotent stem-cell disease, involving the MK lineage, and suggest that the block in maturation during the acute phase can be overcome in vitro.

"Undifferentiated" large cell malignancies: an ultrastructural and immunocytochemical study

One of the most difficult areas of surgical pathology is the classification of "undifferentiated" or "anaplastic" large cell malignant tumors. The differential diagnosis of these tumors includes poorly differentiated carcinomas, large cell malignant lymphomas, and amelanotic malignant melanomas. In this study of 56 such cases, the application of electron microscopy and, in selected instances, of indirect immunofluorescence and immunoperoxidase staining methods have helped us reach a precise histopathologic diagnosis in the majority of neoplasms that were considered to be "undifferentiated" by light microscopy.

A new strain (KW-1) of human chronic myeloid leukemia transplantable in lasat mice

Heterotransplantation of cells from a patient with chronic myeloid leukemia into athymic nude mice and athymic asplenic lasat mice was performed. A serially transplantable tumor cell line (KW-1) was obtained in lasat mice, although the "take" rate was low. The tumor was composed of myeloid cells showing various degrees of differentiation and maturation. The cellular characteristics, the availability of lasat mice and the effect of whole body irradiation or pretreatment with anti-asialo GM1 on heterotransplantation of myeloid cells are described and discussed.

Functional characterization of the cells in chronic neutrophilic leukemia

Light and electron microscopy of neutrophils from chronic neutrophilic leukemia (CNL) did not reveal differences from normal mature neutrophils. However, functional characterization of CNL cells showed marked differences when compared to normal cells. CNL neutrophils were much less viable in suboptimal conditions. Their survival was further reduced by autologous serum and was corrected by normal human serm. CNL cells showed very active phagocytosis, but their bactericidal activity was reduced in suboptimal conditions. The total content of lysozyme and beta-glucuronidase was lower in CNL cells compared to normal neutrophils, but the release of these enzymes from stimulated cells was much higher than normal. This observation is compatible with a marked lysosomal lability. Cells from the patients' peripheral blood and bone marrow showed excessive growth in CFU-C assays. Marked susceptibility of CNL cells to cytotoxic activity of cold agglutinins, SLE sera, and CSFs was observed and may signify qualitative and/or quantitative differences in the membrane structure of CNL neutrophils, as compared to normal cells.

Growth of human malignant micromegakaryocytes in vitro

Mononuclear cells from the peripheral blood of a patient with megakaryoblastic transformation of Philadelphia chromosome-positive chronic myelogenous leukemia were cultured. Morphological and cytochemical studies and cell ploidy determinations were done daily for 4 days. PAS staining of the cells increased progressively during culture. Ultrastructural study of circulating and cultured cells revealed demarcation membranes and alpha granules indicating the cells were micromegakaryocytes. Deoxyribonucleic acid synthesis, determined by 3H-thymidine uptake, peaked at 72 hours. The DNA content of cultured cells was diploid at all times. All 15 metaphases analyzed at 72 hours were Ph1-positive. Malignant (Ph1-positive) megakaryoblasts and micromegakaryocytes grown successfully were capable of partial cytoplasmic maturation as demonstrated by glycogen deposition and increase in subcellular organelles, while endoreduplication was impaired. Malignant megakaryoblasts and micromegakaryocytes can be grown successfully in short term liquid culture and have more complete maturation in vitro than observed in vivo.

Megakaryoblastic transformation of chronic myelogenous leukemia

A 52-year-old man with Ph1-positive chronic myelogenous leukemia (CML) developed a blastic transformation in which the predominant cell type micromegakaryocytes. He did not respond to treatment. A review of the 15 previously reported cases of patients with circulating megakaryocyte abnormalities in association with either CML or a Ph1 chromosome positive myeloproliferative disorder suggests a female predominance rather than the usual male predominance of CML. Survival of the six patients reported as megakaryoblastic transformation of CML as well as this patient was poor.

SEM and TEM studies on the osmotic behavior of control and leukemic lymphocytes and polymorphonuclears

The osmotic behavior of control lymphocytes (CL) and polymorphonuclears (CPMN) was compared with that of cells from patients with chronic lymphocytic leukemia (CLL) and chronic myelocytic leukemia (CML), using the method of gradual dialysis against distilled water. The results were evaluated with a fragiligraph, and by scanning (SEM) and transmission (TEM) electron microscopy. The fragiligraphy curves showed that CLL cells are more resistant to osmotic pressure than the CL, whereas the curves for CPMN and CML cells showed an overlap. Surface alterations in CL appeared as early as 1 min of dialysis, while in CLL cells the membrane did not show major alterations even after 5 min of dialysis. CPMN also showed alterations earlier than CML cells, but this difference was not as prominent as in the case of lymphocytes and was observed for a maximum of 3 min of dialysis. The internal structure of the cells was altered earlier than the surface membrane and this was expressed mainly in the nucleus in both control and leukemic cells. Also in this respect, the internal structure of CL was altered earlier than that of CLL cells, whereas no major differences were observed between CPMN and CML cells.

Studies on chronic myeloid leukemia cell populations with colony-forming abilities in PHA-leukocyte feeder and Robinson assays

Investigation of leukemic colony-forming cells (CFC) in PHA-supplemented cultures requires removal of T lymphocyte precursors prior to culture. Using a method of discontinuous density gradient centrifugation with concurrent depletion of E-rosette forming cells, T lymphocytes were effectively separated from light density CML bone marrow and blood cell fractions. Consequently, in light density fractions (1.056 and 1.059 g/ml) pure leukemic colony growth was obtained in the PHA-leukocyte feeder (PHA-l.f.) assay. Fraction 1.062 g/ml also yielded pure leukemic colonies in most experiments. Comparison of the density distributions of leukemic PHA-l.f. CFC and Robinson CFC revealed that both CFC populations had congruent density profiles in most patients. In others PHA-l.f. CFC were found to be of somewhat higher density than Robinson CFC. The most striking divergence was apparent in a patient in blast crisis. The findings suggest that different subsets of precursor cells within the CML population proliferate in PHA-l.f. and Robinson colony methods. Both colony techniques are thus potentially useful for discriminating subpopulations of colony-forming cells in chronic myeloid leukemia.

Ultrastructural diagnosis of large cell 'undifferentiated' neoplasia

Large cell undifferentiated neoplasia' provides a generic designation for a heterogeneous group of neoplasms which by histological study, are devoid of discriminate architecture and appear under the light microscope as patternless sheets of large cytoplasmic cells. The interpretation of such a tumour will routinely present significant problems in differential diagnosis. By conventional light microscopy the neoplasm may subjectively be judged to represent a certain form of carcinoma or large cell lymphoma, but often identification is relegated to a label of "consistent with', or "undifferentiated malignant neoplasm'. Such interpretations are not acceptable and preclude rational management decisions. This paper has analysed tumour cell ultrastructure derived from a spectrum of clinicopathological situations involving the diagnostic problem of the large cell undifferentiated neoplasm. The fine structural morphologies of these enigmatic tumours are often sufficiently specific to allow resolution of the differential diagnosis and assignment of cell type. Diagnostic electron microscopy, in coordination with histopathology and clinical information, will often play a significant role in solving complex problems involving the differential diagnosis of large cell undifferentiated neoplasms.

TdT-positive and TdT-negative human leukemic cells: specific density and morphology

Peripheral blood cells from 9 E- and 6 D+ SIg- ALL patients and from 11 CML patients in TdT+ blastic crisis were subjected to discontinuous albumin gradient separation according to Dicke's method, and TdT assayed in the six fractions recovered therefrom. The major results were: (i) in E- ALL and in CML-BC, TdT+ cells could be recovered either within a narrow range of specific densities or were spread over most of the gradient, which might suggest differences in cell maturation among the patients; (ii) in some instances, most leukemic blasts were found in TdT-negative or faintly positive fractions; (iii) in most, but not all, E- All and BC, the majority of TdT+ cells was found in low density fractions; (iv) all E+ ALL had high density TdT+ cells. Cell Fractions of most patients were also examined at the electron microscope, and correlations between morphology and marker characterization were tentatively drawn.

Blastic transformation of a well-differentiated monocytic leukemia: changes in cytochemical and cell surface markers

The clinical course of a patient with a well-differentiated monocytic leukemia which later underwent blastic transformation is described. Cytochemical, ultrastructural and cell surface analysis data were obtained at periods throughout her illness and correlated with the blastic transformation. Although surface markers characteristic of monocytic leukemia persisted, a deficiency of peroxidase in the granules of this patient's monocytes was observed as well as loss of alpha-naphthyl butyrate esterase staining during transformation.

[Morphogenesis of Gaucher's cells and cells similar to them (in myelosis)]

The cytohistological resemblance between Gaucher's cells and similar cells of the bone marrow in cases of myelosis is great but their electronoptical pictures vary,. In Gaucher's cells there are membranous limited and non-limited corpuscles, composed of typical convoluted tubules, which do not contain lipids, they may be found even in the cisterns of the rough endoplasmatic reticulum and in perinuclear cisterns. They probably represent the proteinic bearer of glucosyl-ceramids, which are extracted during standard histological techniques and therefore do not form part of the histological picture. The gradual loss of the membraneceous lining around these corpuscles is probably the expression of differently advanced states of lysosomatic break down. The Gaucherlike cells of the bone marrow are apparently macrophages with many cytolysosomes, the tubular portions of which are usually not membranous limited, do not have any tendency of screwing and they differ from the previous ones in many other details.

Ultrastructural cytochemical localizations by back-scattered electron imaging of white blood cells

White blood cells have been studied in the back-scattered electron imaging (BEI) mode of scanning electron microscopy (SEM) with cytochemical methods for endogenous peroxidase, acid phosphatase, and a silver-staining method for nuclei. Peroxidase-positive granules were seen with good contrast and resolution in myeloid precursor cells and acid phosphatase activity was easily detected in macrophages and monoblasts. Silver staining permitted recognition of the shapes and location of the nuclei. In spite of the cytochemical procedures, cell surface structures were reasonably well-preserved in all methods, making direct correlation of BEI and secondary electron imaging (SEI) images an attractive feature in cell research with the scanning electron microscope.

Chronic myelomonocytic leukemia in childhood

A four-year-old child with recurrent infections and increasing hepatosplenomegaly over a three-year period was evaluated. Increased numbers of myeloid precursors packed the bone marrow and infiltrated the peripheral blood. A diagnosis of chronic myelogenous leukemia (CML) was considered but could not be confirmed by laboratory studies appropriate for the types of CML usually observed in childhood. Examination of the patient's peripheral blood smears revealed many atypical monocytoid cells with unipolar hairy projections. Scanning electron microscopy showed these to be leukemic monoblasts with characteristic broad-based ruffles on the cell surface. A population of myeloid precursors possessing narrow ridge-like profiles was also observed. Progressive infiltration of the spleen caused hypersplenism which necessitated splenectomy. Subsequently, massive liver and bone marrow involvement led to the patient's death. Terminally, the proliferating blast cells were demonstrated to be leukemic monoblasts by analysis of cytochemical staining patterns, surface immunoglobulins, serum lysozyme levels, and monocyte-mediated antibody-dependent cellular cytotoxicity studies. The findings in this case are most compatible with a diagnosis of chronic myelomonocytic leukemia (CMML), a condition not previously described in childhood. Several myeloproliferative disorders with prolonged survival have been reported in children, but special studies were not performed to determine which cell lines were abnormally proliferating. The similarities between these children and our patient with CMML suggest that monocyte studies may be useful in the diagnosis of these unusual disorders, provide insights into their pathogenesis, and aid in the selection of appropriate therapy.

Significance of Phi bodies in acute leukaemia

Material from 39 patients with acute leukaemia was investigated with the peroxidase cytochemical reaction using 3,3'diaminobenzidine (DAB) and other substrates in order to test their sensitivity in detecting myeloid differentiation. The proportion of positive blasts and of cases with Auer rods in acute myeloid leukaemia (AML) was significantly greater with DAB than with benzidine. In addition, Phi bodies were demonstrated in AML blasts only when DAB was used; Phi bodies were also observed in two out of seven cases of chronic granulocytic leukaemia in "myeloid" blast crisis but were not seen in any case of acute lymphoblastic leukaemia. Phi bodies were more numerous when the reaction was carried out at pH 9.7, and their number was significantly reduced in the presence of 3-amino 1,2,4-triazole. Both findings suggest that the Phi bodies derive from catalase-containing granules (microperoxisomes) and are distinct from Auer rods, which derive from peroxidase-containing (primary) granules. Like Auer rods, Phi bodies appear to be characteristics of immature myeloid cells in leukaemia but are seen with a higher frequency than Auer rods in acute myeloid leukemia.

Nucleolar immunofluorescence in bone marrow specimens of human hematological malignancies

Leukemic cells and myeloma cells were studied in bone marrow of untreated patients with acute and chronic myeloid leukemia, chronic lymphocytic leukemia, and multiple myeloma to provide more information on the nucleolar immunofluorescence produced by antibodies no nucleoli of HeLa cells. The nucleolar immunofluorescence was mainly observed in myeloblasts of myeloid leukemias an in immature as well as mature cells of the plasmacytic or lymphocytic cell lines of multiple myeloma or chronic lymphocytic leukemia. With respect to the nucleolar immunofluorescence, both positive and negative populations of cells were noted in the specimens of all patients studied.

Electron microscope cytochemical analysis of chronic myelocytic leukemia: a case report

A patient with Philadelphia chromosome positive CML was studied to characterize the blast transformation. Peripheral blood and bone marrow at the onset of the blast crisis were evaluated with cytochemistry, chromosome analysis, cell surface markers, terminal transferase assay, and electron microscopy. Although light microscopic examination and cytochemistry suggested lymphoblastic morphology, ultrastructural cytochemistry demonstrated the myelomonocytic features of the transformation. This study suggests that electron microscopic cytochemistry is useful in evaluating the heterogeneous nature of the blast phase of CML.

The different origin of primary and secondary chromosome aberrations in cancer

We have proposed a hypothetical model to explain the role of chromosomal aberrations in malignant development. In this model we postulate two kinds of chromosomal changes: (1) primary, active changes caused by direct interaction between the oncogenic agent and the hereditary material of the host cell. These changes are mainly somatic mutations, but may also be associated with directed structural changes visible in the microscope; and (2) secondary, passive changes arising randomly by nondisjunction and structural rearrangements. They are followed by selection of cells with changes that amplify the primary change and thus appear as nonrandom chromosome patterns. This hypothesis is discussed in the light of 1827 cases of human malignancy in which we have recently surveyed and systematized chromosomal aberrations. Special support for the idea of somatic mutations as the initiator of malignant development comes from work of Knudson and collaborators in human retinoblastoma. The Ph1 chromosome, predominant during the chronic phase of chronic myeloid leukemia (CML), is proposed as an instance of a primary change, whereas the chromosome changes during the blastic crisis of CML will illustrate the secondary changes. The most common of these secondary changes is actually the doubling of the Ph1 and thus an amplification of the primary change. The increase in number of copies of a specific chromosome reported by Green and collaborators demonstrates that this kind of amplification can result in direct response to the need for a specific gene located in that chromosome.

Tumor-host cell interactions in rats bearing Shay chloroma--ultrastructural observations in animals receiving specific and nonspecific cancer immunotherapy

Tumors of the rats bearing Shay chloroma treated with specific (polymerised tumor particles) and nonspecific (PPD tuberculin) cancer immunotherapy were assessed on electron microscopy with special emphasis on the interactions between the host's effector cells and the tumor targets. Attempt was made to cast light on the differences previously found in the effects of these two immunotherapy models on this particular tumor. Lymphocytes were found apposited to the tumor cells in all animals, but the nature of this contact varied from intimate in series B and C (animals receiving PPD) to extremely loose in series A (specific mode of therapy instituted). The same was true with the cells of the MPS (mononuclear phagocyte system), which sometimes seemed to wrap the tumor cells by their slender cytoplasmic processes. A prominent hypertrophy and orientation of the Golgi complex of a small lymphocyte, recently shown to be characteristic of cytolytic T-cells in vitro, was visualized in one case of series C. The observations were interpreted to lend support to the idea that blocking activity due to the polymerised strong tumor antigens could be responsible for the adverse effects of the active specific cancer immunotherapy in this particular system.

Meningeal granulocytic sarcoma without evidence of leukemia. Light and ultrastructural study of one case

An unusual case of meningeal granulocytic sarcoma without evidence of Leukemia is presented. The patient, a 40 year old female, presented with a chronic subdural haematoma. Three months later a large meningeal tumor was discovered adjacent to the previous haematoma and was found to be a granulocytic sarcoma by the use of electron microscopy. The tumor was treated by surgical excision followed by radiotherapy and chemotherapy. The patient remains free of symptoms and without evidence of leukemia in the peripheral blood or bone marrow 9 months after the diagnosis was established. The ultrastructural findings in the tumor and diagnostic difficulties often encountered are emphasized.

Ultrastructural study of B-bodies in leukapheresed cells of patients with acute leukemia

Peculiar inclusions, which we call B-bodies, have been observed in cells collected by leukapheresis from patients with acute leukemia. B-bodies, which often have virus-like features, were present in blast cells of 24 (44%)( of the 54 patients examined; in 16 out of 29 with acute myelogenous leukemia, 5 out of 16 with acute lymphoblastic leukemia, 2 out of 3 with undifferentiated leukemia, and 1 out of 2 with myelogenous leukemia in blastic transformation. The ultrastructure of these apparently polymorphic inclusions was always based on a system of of cytoplasmic channels containing dense, axial filaments. Patients with B-bodies were mostly women near menopause (70% of the positives).

The acute monocytic leukemias: multidisciplinary studies in 45 patients

The clinical and laboratory features of 37 patients with variants of acute monocytic leukemia are described. Three of these 37 patients who had extensive extramedullary leukemic tissue infiltration are examples of true histiocytic "lymphomas." Three additional patients with undifferentiated leukemias, one patient with refractory anemia with excess of blasts, one patient with chronic myelomonocytic leukemia, one patient with B-lymphocyte diffuse "histiocytic" lymphoma and one patient with "null" cell, terminal deoxynucleotidyl transferase-positive lymphoblastic lymphoma had bone marrow cells with monocytic features. Another patient had dual populations of lymphoid and monocytoid leukemic cells. The true monocytic leukemias, acute monocytic leukemia (AMOL) and acute myelomonocytic leukemia (AMMOL), are closely related to acute myelocytic leukemia (AML) morphologically and by their response to chemotherapy. like AML, the leukemic cells from the AMMOL and AMOL patients form leukemic clusters in semisolid media. Cytochemical staining of leukemic cells for nonspecific esterases, presence of Fc receptor on the cell surface, phagocytic ability, low TdT activity, presence of surface "ruffles" and "ridges" on scanning EM, elevations of serum lysozyme, and clinical manifestations of leukemic tissue infiltration are features which accompanied monocytic differentiation in these cases.

Ultrastructural features of basophil and mast cell granulopoiesis in blastic phase Philadelphia chromosome-positive leukemia

Ultrastructural and ultracytochemical studies were performed on blood and bone marrow specimens from 18 patients with Philadelphia chromosome-positive blastic leukemia; 7 patients were in blast transformation following a typical history of chronic myelogenous leukemia and 11 patients presented with "acute leukemia." The patients were divided into 2 morphologic groups on the basis of light microscopic and cytochemical observations. In group I, which consisted of 11 patients, the proliferating cells were "lymphoid" in appearance and demonstrated many cytochemical, biochemical, and immunologic features similar to those of the lymphoblasts of non-T, non-B acute lymphoblastic leukemia. In group II, which consisted of 7 patients, the proliferating cells were myeloid in appearance. On the basis of ultrastructural observations, the 11 group I patients were divided into 2 subgroups, A and B. Subgroup IA, consisting of 5 patients, was characterized by blasts that demonstrated no differentiating features. In subgroup IB, consisting of 6 patients, 20-30% of the leukemic cells contained inclusions that resembled leukemic mast cell or basophil granules. The leukemic cells in the 7 group II patients manifested myeloid characteristics by light microscopy and prominent basophil and mast cell granulopoiesis by electron microscopy. Abnormalities of other myeloid cell lines were also observed in both the lymphoid and myeloid groups of patients.

Expression of a cell surface glycoprotein (p180) related to cell-substratum adhesion during differentiation of mouse myeloid leukemia cells

Mouse myeloid leukemia M1 cells were induced to differentiate in vitro into macrophages and granulocytes by various inducers including ascitic fluid. Differentiated M1 cells induced with ascitic fluid expressed a differentiation-associated cell surface glycoprotein with a molecular weight of 180,000 (p180), which can be labeled by lactoperoxidase-catalyzed radioiodination or metabolic labeling with L-[14C]fucose. p180 was also induced by treatment with conditioned medium of hamster embryo cells, dexamethasone, dibutyryl cyclic adenosine 3':5'-monophosphate, and prostaglandin E1. Ascitic fluid, conditioned medium of hamster embryo cells, and dexamethasone induced all the differentiation-associated properties tested, whereas dibutyryl cyclic adenosine 3':5'-monophosphate and prostaglandin E1 induced lysozyme activity and adhesiveness to the substratum but not phagocytosis, locomotive activity, Fc receptors, or morphological changes. The adherent cells induced by dibutyryl cyclic adenosine 3':5'-monophosphate produced a large amount of p180, while the floating cells produced very little, but no difference was detected in the lysozyme activities of the two cell types. These results suggest that p180 is associated with cell-substratum adhesion of differentiated M1 cells.