Cytomorphological description and intra-observer agreement in whole slide imaging for canine lymphoma.

Whole slide imaging (WSI) uses robotic microscopes for computerising entire slides into digital images. The aim of this study was to assess the agreement between WSI and optical microscopy for evaluating canine lymphoma cytological samples. Forty-four slides were computerised using a WSI scanner and the digital and glass slides were examined by three observers with different levels of expertise. Morphology and grade of lymphoma were scored on the basis of the updated Kiel classification and intra-observer agreement was assessed. The accuracy of determining the grade of lymphoma with digital and glass slides based on the results of flow cytometry (FC) was established. The overall intra-observer agreement for cytomorphological features was fair to moderate (κ=0.34-0.52) for the three observers and moderate (κ=0.44-0.53) for the evaluation of grade of malignancy. The diagnostic agreement between FC and digital slides was slight (κ=0.16) for the inexperienced observer, fair (κ=0.32) for the mildly experienced observer and moderate (κ=0.50) for the very experienced observer. The diagnostic agreement between FC and glass slides was fair (κ=0.37) for the inexperienced observer, substantial (κ=0.63) for the mildly experienced observer and moderate (κ=0.50) for the very experienced observer. These findings underline the importance of observer experience in determining the grade of malignancy, especially if digital slides are used. The study also identifies some technical limitations of the WSI scanner used in this study, mainly linked to image quality, which might affect the morphological evaluation of neoplastic cells.

Label-Free Optofluidic Nanobiosensor Enables Real-Time Analysis of Single-Cell Cytokine Secretion.

Single-cell analysis of cytokine secretion is essential to understand the heterogeneity of cellular functionalities and develop novel therapies for multiple diseases. Unraveling the dynamic secretion process at single-cell resolution reveals the real-time functional status of individual cells. Fluorescent and colorimetric-based methodologies require tedious molecular labeling that brings inevitable interferences with cell integrity and compromises the temporal resolution. An innovative label-free optofluidic nanoplasmonic biosensor is introduced for single-cell analysis in real time. The nanobiosensor incorporates a novel design of a multifunctional microfluidic system with small volume microchamber and regulation channels for reliable monitoring of cytokine secretion from individual cells for hours. Different interleukin-2 secretion profiles are detected and distinguished from single lymphoma cells. The sensor configuration combined with optical spectroscopic imaging further allows us to determine the spatial single-cell secretion fingerprints in real time. This new biosensor system is anticipated to be a powerful tool to characterize single-cell signaling for basic and clinical research.

Effect of bafilomycin and NAADP on membrane-associated ATPases and respiration of isolated mitochondria of the murine Nemeth-Kellner lymphoma.

The goal of the study was to estimate the effect of a selective V-type H+ -ATPase inhibitor bafilomycin A1 and nicotinic acid adenine dinucleotide phosphate (NAADP) on energetic processes in NK/Ly cell by directly measuring the respiration of isolated mitochondria and ATPase activities. NAADP (7 µM) increased the activity of Na+ /K+ -ATPase in the postmitochondrial fraction of NK/Ly cells, but lower concentration of NAADP decreased it (0.1 and 1 µM). The increase the activity of plasma membrane Ca2+ ATPase (PMCA) under NAADP application (1 and 7 µM) was observed. However, NAADP (1 µM) decreased activities of sarcoendoplasmic reticulum Ca2+ -ATPase (SERCA) and basal Mg2+ -ATPase. Bafilomycin A1 (1 µM) increased the activity of Na+ /K+ -ATPase and potentiated the effect of NAADP (1 µM) on this pump. At the same time, bafilomycin A1 (1 µM) completely prevented all effects of NAADP (1 µM) on activities of PMCA, SERCA, and basal Mg2+ -ATPase, confirming that these effects are dependent on acidic stores. Bafilomycin A1 or NAADP decreased respiratory and oxidative phosphorylation rates in NK/Ly mitochondria when α-ketoglutarate was used as substrate in contrast to succinate. Thus, α-ketoglutarate oxidation is more sensitive to bafilomycin A1 and NAADP influences compared with succinate oxidation. However, bafilomycin A1 + NAADP and any of these compounds separately lead to full uncoupling of mitochondria after ADP addition irrespectively to substrate used. Bafilomycin A1 affects isolated tumor mitochondria more effectively in combination with NAADP. Bafilomycin and NAADP alter some membrane-associated ATPases and inhibit respiration in mitochondria of the Nemeth-Kellner lymphoma. SIGNIFICANCE OF RESEARCH PARAGRAPH: Bafilomycin A1 potentiates the effect of NAADP by inhibiting the mitochondrial energetic process in lymphoma cells and activity of Na+ /K+ -ATPase. The obtained data show promising possibility to use bafilomycin A1 and NAADP as chemotherapeutic agents for lymphoma cells treatment. This is important because lymphomas are seventh most common form of cancer. Today the lymphoma mortality is 15% to 30%, whereas the effectiveness of malignant neoplasms treatment is less than 50%.

Nanoscale Quantifying the Effects of Targeted Drug on Chemotherapy in Lymphoma Treatment Using Atomic Force Microscopy.

The applications of targeted drugs in treating cancers have significantly improved the survival rates of patients. However, in the clinical practice, targeted drugs are commonly combined with chemotherapy drugs, causing that the exact contribution of targeted drugs to the clinical outcome is difficult to evaluate. Quantitatively investigating the effects of targeted drugs on chemotherapy drugs on cancer cells is useful for us to understand drug actions and design better drugs. The advent of atomic force microscopy (AFM) provides a powerful tool for probing the nanoscale physiological activities of single live cells. In this paper, the detailed changes in cell morphology and mechanical properties were quantified on single lymphoma cells during the actions of rituximab (a monoclonal antibody targeted drug) and two chemotherapy drugs (cisplatin and cytarabine) by AFM. AFM imaging revealed the distinct changes of cellular ultramicrostructures induced by the drugs. The changes of cellular mechanical properties after the drug stimulations were measured by AFM indenting. The statistical histograms of cellular surface roughness and mechanical properties quantitatively showed that rituximab could remarkably strengthen the killing effects of chemotherapy drugs. The study offers a new way to quantify the synergistic interactions between targeted drugs and chemotherapy drugs at the nanoscale, which will have potential impacts on predicting the efficacies of drug combinations before clinical treatments.

Signet ring cell lymphoma with plasmacytic differentiation in a pig.

A case of signet ring cell lymphoma in a 3-year-old mixed-breed sow is described. Macroscopical examination revealed enlargement of superficial, thoracic and abdominal lymph nodes and multiple tumor masses in the liver. The neoplastic tissue was composed of follicle center-like structures, in which neoplastic cells with Russell bodies were conspicuous. The bodies were immunostained for IgM (κ), and corresponded to moderately dense amorphous material within markedly distended cisternae of rough endoplasmic reticulum (RER) at the ultrastructural level. In contrast to typical signet ring cell lymphoma, the component cells of which resemble follicular center B lymphocytes with poorly developed RER, most neoplastic cells had features of plasma cells characterized by a cartwheel arrangement of heterochromatin and development of RER. Signet ring cells frequently had one or a few large Russell bodies occupying the entire cytoplasm, which may have been caused by abundant synthesis and defective secretion of immunoglobulin.

Structural and biochemical changes in mitochondria after cisplatin treatment of Dalton's lymphoma-bearing mice.

Cisplatin treatment of tumor-bearing mice and analysis of ultrastructural features of mitochondria in the kidney and Dalton's lymphoma cells showed the appearance of more roundish mitochondria with thickened membranes. It also caused the reduction in the number and irregularity in the shape of cristae and formation of vacuoles in the mitochondria. After cisplatin treatment, decreased level of protein, succinate dehydrogenase activity, and increased level of lipid peroxidation were noted in Dalton's lymphoma tumor cells and kidney. Cisplatin-mediated decrease in SDH activity, GSH level and an increase in LPO in the mitochondria of kidney could play an important role to produce nephrotoxicity. However, in DL cells, decrease in cellular GSH could be noteworthy than mt-GSH, along with decrease in SDH activity and increase in LPO in the cisplatin-mediated anticancer activity. These changes could play an important role to produce both the cisplatin-mediated effects i.e. anticancer activity and nephrotoxicity. Cisplatin-induced biochemical and ultrastructural changes in mitochondria after cisplatin treatment should be an important factor in the development of biochemical injury in mitochondria and affecting the overall metabolism in the cells. The findings from the present studies indicate multilevel effect of cisplatin in the cells and do support the earlier view that mitochondria could be a critical target in cisplatin-mediated anticancer activity and toxicity in the hosts.

[Pathological features and ultrastructure of N-methyl-N-nitrosourea (MNU)-induced thymic lymphomas in mice].

The objective of study was to investigate the origin and to classify the subtype of N-methyl-N-nitrosourea (MNU)-induced thymic lymphomas in mice. Histopathologic, immunohistochemical and ultrastructural studies were performed to analyze the pathological features of the neoplasms. The results showed that the thymus in all cases became totally replaced by sheets of cells of the lymphoid series. All the tumors coexpressed CD3 and TdT. Transmission electron microscopic study showed the plasma membranes of malignant lymphoma cells were smooth. The nuclear profiles were usually regular, with varying percentage of convoluted nuclei. Few cell organoids were observed in cytoplasm. In conclusion, all the MNU-induced tumor classified by histopathologic, immunohistochemical and ultrastructural studies as precursor lymphoblastic lymphoma that were unquestionably related to the thymus origin and T-cell lineage.

A case of canine vasotropic and vasoinvasive nonepitheliotropic lymphoma with unusual tumor cells and extensive dermal necrosis.

A 14-year-old, spayed female Shih-tzu dog presented with masses in the dorsal aspect of cervical region and digit of the right anterior limb. Extensive necrosis was seen in the dermal tissue overlying the tumor, and diffuse round cell proliferation and infiltration were seen histologically from the superficial dermis to the deep dermis. Two types of proliferating cells were present: lymphoblast-like cells with round-oval, vesicular nuclei and moderate-large nucleoli; and smaller cells with characteristic irregularly shaped nuclei. Electron microscopy of these smaller cells showed cerebriform, pleomorphic nuclei with a chromatin pattern characteristic of lymphoid cells, as seen in lymphoblast-like tumor cells. Immunohistochemically, both types of tumor cells were positive for CD3. Most vessel walls had been invaded by tumor cells, resulting in extensive dermal necrosis and hemorrhage. Based on these histopathological findings, the tumor was diagnosed as vasotropic and vasoinvasive nonepitheliotropic lymphoma, characterized by a notable presence of unusual tumor cells with irregularly shaped nuclei and extensive dermal necrosis.

Carcinoma versus cytokeratin-positive lymphoma: a case report emphasizing the diagnostic role of electron microscopy.

Lymphoma diagnosis rarely needs electron microscopy (EM), but one area where it can be useful is in the distinction of cytokeratin-positive lymphoma from carcinoma. The authors describe such a case, where difficulties were encountered due to lack of antibody specificity, distinguishing reactive from tumoral cells, and suboptimal sampling for EM. The tumor was in a lymph node next to the right submandibular gland in a 69-year-old man. This was a malignant tumor, composed of sheets of monomorphic large round cells. Interpretation on the part of a team of pathologists who examined this tumor was divided. On histological sections, the differential diagnosis was between carcinoma and lymphoma, which was modified to cytokeratin-positive lymphoma versus carcinoma since tumor cells were found to be cytokeratin-positive. EM of tumor retrieved from formalin showed plasmablastic features, in keeping with lymphoma with plasmablastic differentiation, one of the light microscopy diagnoses. The moderately strong positivity of cytokeratin and the positivity for Ber-EP4, however, supported carcinoma, and further sampling for EM was carried out, specifically on a cytokeratin-positive area of the wax block. Tonofibrils were found, supporting carcinoma. The final diagnosis was undifferentiated carcinoma with unknown primary site. The study emphasizes the need to take into account the imperfect specificity of cytokeratin, which can be found in several hemolymphoid neoplasms, to distinguish reactive from neoplastic cells, and to secure appropriate sampling for EM. This is one of the occasions where dewaxing (of an immunohistochemically defined wax block) offers positive advantages, despite compromised structural preservation, in the search for diagnostically important organelles.

Ultrastructural studies of jaw lymphomas and apoptosis.

Research on ultrastructural cytopathological changes and apoptosis that occur in jaw lymphoma were done by using electron microscopy and ground sections. The author described this tumor in 1977-1978 as a highly malignant and lethal condition affecting children between 2 and 8 years (mean age 5 years). A duration of illness between 2 and 3 weeks is common and with a general condition of severe toxicity, anemia, and high body temperature. Clinical and pathological features of 24 children with jaw lymphoma seen in the Maxillofacial Unit, Surgical Specialized Hospital, Medical city, Baghdad, are described. Thirteen males and 11 females were included, with a death rate at 91.1%. The morphological characteristics were examined by ground sections. Lymphoblastic lymphoma features were observed and apoptotic changes were seen in some of the cells. Electron microscopy showed a high number of mitotic figures and lymphoblast transformation to plasma cells with high nucleo-cytoplasmic ratio. Some cells had double nuclei and some nuclei were more convoluted. Apoptotic changes were seen in some cells; chromatin clumps aggregated near the nuclear membrane. Cytoplasmic processes and mitochondria showing degeneration and virus-like particles were seen in both nuclei and cytoplasm. The presence of a high mitotic figure with active oncogenic virus growth and reduced apoptosis is a poor prognostic feature in jaw lymphoma.

Biological characteristics of cultured cells derived from various types of human brain tumors.

We placed in culture brain tumors from 45 cases (7 cases of astrocytoma, 2 from oligodendrogliomas, 2 glioblastomas, 2 ependymomas, 13 meningiomas, 6 pituitary adenomas, 5 neurinomas, a malignant lymphoma, a choroid plexus papilloma, and 6 metastatic tumors) and succeeded in making a primary culture from 33, and maintained 17 in vitro over a considerable period of time (greater than three months). In the early period of the primary cultures, the astrocytoma cells had cytoplasmic processes which contacted each other, the oligodendroglioma cells were small and spindle-shaped, the glioblastoma cells were neoplastic with pleopmorphic features and possessed cytoplasmic processes, the ependymoma cells formed a rosette-like cell arrangement, the meningioma cells were spindle- or round-shaped cells and characterized as forming psammoma bodies, the pituitary adenoma cells were round- or oval-shaped cells and produced growth hormone (GH), adenocorticoid tropic hormone (ACTH), prolactin, or other hypophyseal hormones, the choroid plexus papilloma cells were round-or polygonal and showed a papillary cell arrangement, the neurinoma cells were spindle- or fibrous-shaped cells, and the malignant lymphoma cells were round and formed cell aggregates floating in the culture medium.

Ultrastructural studies on malignant lymphoma in dogs, with the use of computer imaging.

Malignant lymphoma is one among the most often diagnosed malignant tumors in dogs. In the course of the disease lymphatic glands become enlarged and infiltrations form in internal organs or skin. Studies on the ultrastructure of neoplastic lymphocytes were carried out on a formalin-fixed and parafin-embedded material with a Hulquist and Karlsson's method. Numerous aplastic cells with large nuclei, abundan eu- or heterochromatin and unstabilised nucleolus were observed on TEM slides. The cells differed clearly from normal lymphocytes with highly condesed heterochromatin and stabilised nucleoli.

Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases.

Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with 'malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer-Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.

A new method to extract nuclei from paraffin-embedded tissue to study lymphomas using interphase fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) is difficult to accomplish using thin-sections of paraffin-embedded lymphoid tissue because of the high cellularity and truncated cells that interfere with accurate scoring of individual nuclei. We modified and tested a new technique to isolate individual nuclei from tissue cores of paraffin-embedded tissue processed with xylene, proteinase K, citric acid, and pepsin. The efficacy of this method to study paraffin-embedded tissue was investigated in six normal lymph nodes or tonsils and 32 malignant lymphomas including five mantle cell, five follicular, five Burkitt, five extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue, five anaplastic large-cell, and seven diffuse large B-cell. Fusion of CCND1 and IgH, BCL2 and IgH, c-myc and IgH, and MALT1 and API2 were detected using probes with a dual-fusion FISH strategy. Anomalies involving ALK and BCL6 were detected using break-apart FISH probes. FISH studies were successful for each of the 38 specimens. Chromosome anomalies were detected in each malignant specimen, but not in the normal lymphoid tissue. The correct chromosome anomaly was detected in 22 of 22 specimens with genetic abnormalities that were established by other genetic techniques. This FISH technique is useful to detect chromosome anomalies with high sensitivity and specificity in paraffin-embedded tissue and may provide important diagnostic and prognostic genetic information.

Abdominal lymphoma: differentiation from pancreatic carcinoma with Doppler US.

BACKGROUND: Marked lymphadenopathy around the pancreas due to lymphoma (abdominal lymphoma) occasionally can mimic a total pancreatic carcinoma on ultrasonography (US). We investigated whether US and color Doppler US allowed differentiation between those pathologies. METHODS: We analyzed the US and color Doppler results of 12 cases of abdominal peripancreatic lymphoma and 21 cases of total pancreatic carcinoma. RESULTS: With regard to shape, echogenicity of the lesion, and mode of vascular involvement, there was no difference between groups. With regard to maximal velocities and resistive indices of the involved vessels, there was no difference between groups. However, the presence of turbulent flows in the involved vessels was seen exclusively in the pancreatic carcinoma group. CONCLUSION: The presence or absence of turbulent flow in the involved vessels is a very important finding for differentiating abdominal lymphomas from total pancreatic carcinomas.

Intracranial lymphomas in simian retrovirus-positive Macaca fascicularis.

Two young adult Macaca fascicularis each had unilateral mydriasis and ptosis. Both animals were euthanatized, monkey No. I for progressive neurologic signs and monkey No. 2 because of a positive intradermal tuberculin test. At necropsy, each animal had a single intracranial mass on the ventral surface of the midbrain, surrounding the oculomotor nerve. Histologically, both masses were immunoblastic lymphomas. Immunohistochemical staining revealed the neoplasms to be of B-cell origin. Simian retrovirus (SRV) was isolated from both monkeys, but simian immunodeficiency virus was not found. Both animals lacked antibody to SRV. Both animals had antibodies to Epstein-Barr-like virus (EBV), but EBV antigens were not found by immunohistochemistry. Polymerase chain reaction analysis for integrated EBV DNA was unproductive. One of the animals (monkey No. 2) had a pulmonary infection with Mycobacterium avium, suggesting that immunosuppression was present. These cases represent a unique and previously undescribed type of solitary lymphoma in SRV-infected macaques.

Sensitivity to macrophages decreases with tumor progression in the AKR lymphoma.

Resistance to immune reactions, innate or acquired, may be one of the mechanisms responsible for the progression of tumors. We have, indeed shown higher numbers of macrophages surrounding low- as compared to high-malignancy cells. In the present study we examined the level of cell surface molecules known to determine sensitivity to macrophages, namely galactose (GAL) and sialic acid (SA) residues. A histochemical assay for identification of SA by electron microscopy showed a higher cell surface content on metastatic (MT) than on primary (PT) tumor cells. The FACS data seen with fluorescent lectins showed a higher binding of Sambucus nigra agglutinin, which identifies SA attached to terminal GAL in -2.6 or -2.3 linkage, in MT than in PT cells. Binding of Maakia amurensis lectin (MAL-1), which identifies SA at position 3 of GAL, showed that the MT cells contain two subpopulations, one binding more MAL-1 and another less. Cell sorting showed a more aggressive behavior of the first population. The comparison of Peanut agglutinin (PNA) binding, which identifies GAL, demonstrated a decreased amount of PNA receptors in MT as compared to PT cells. Western blot analysis of the membranal proteins with different lectins, identified 3 sialylated glycoproteins. The 88 kDa glycoprotein had no significance for metastatic potential. The 130 kDa glycoprotein was higher in MT than on PT cells. The 220 kDa glycoprotein was practically present only on MT cells. The tendency observed was of a higher level of membranal glycoconjugates terminally sialylated with subterminal galactose residues, inMT cells as compared to PT cells. This may explain the recently found decrease in apoptotic cell death with increasing aggressiveness of the AKR lymphoma and suggests a lower sensitivity to macrophages with tumor progression. Treatment based on the reduction in sialic acid content might render the tumor cells more vulnerable to macrophages. We found, indeed, that Wheat germ agglutinin (WGA) injected in vivo, exerted an inhibitory effect on growth of the lymphoma. We found moreover that WGA-treated tumor cells were more sensitive than nontreated cells to macrophages in vitro.

Computerized morphometric analysis of human leukemic and lymphomatous cells in various histological environments of central nervous system.

The leukemic and lymphomatous cells appear within the central nervous system (CNS) in 5 different environments: in CNS vessels, perivascular spaces, meninges, nervous tissue and in CNS hemorrhages. A computerized analysis of geometric and densitometric parameters of neoplastic cells in these compartments were done for better recognition of penetration and spreading of leukemia and lymphoma within the CNS. A post-mortem neuropathological investigations were carried out on 16 patients deceased due to acute myeloblastic leukemias (M1, M2), blastic phase of chronic myelogenous leukemia, lymphoblastic lymphoma and acute lymphoblastic leukemia. Following nuclear parameters of neoplastic cells were analyzed: area, "form factor", mean, minimal and maximal density. An evident differentiation of nuclear parameters within the CNS environments was found. The nuclei within the perivascular spaces and especially in CNS hemorrhages were significantly shrunken and dense (p < 0.01), but not evidently deformed. The intracerebral infiltrates appeared to be most differentiated group (p < 0.01). Morphometric values of leukemic and lymphomatous cells show regressive changes of neoplastic cells within the CNS perivascular spaces, nervous tissue and in CNS hemorrhages. These changes depend on unfavorable factors in the mentioned CNS environments, and also on time of cell persistence in these regions. Meninges were found to be the only CNS structure facilitating the survival and proliferation of leukemic and lymphomatous cells.