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Objective: To test whether automated measurements of cortisol-induced changes in the leukocyte differential can provide an early marker of myocardial infarction, especially when combined with the rapid creatine kinase-MB isoenzyme.Design: A prospective, blinded study of these measurements at the time of initial assessment in the emergency department.Setting: Large multispecialty clinic hospital.Patients: 511 consecutive patients presenting to the emergency department with chest pain. One hundred twenty-seven patients with infection, trauma, or metastatic cancer or receiving myelosuppressive or glucocorticoid therapy were excluded.Measurements: Automated leukocyte differentials, rapid creatine kinase-MB levels, cortisol levels, and routine clinical measurements.Results: Of 69 patients with myocardial infarction, only 39% had diagnostic electrocardiographic ST-segment elevation. ST-segment elevation had a specificity of 99% and a positive predictive value of 93%. A relative lymphocytopenia (lymphocyte decrease < 20.3%) or elevated rapid creatine kinase-MB level (> 4.7 ng/mL) was more sensitive than ST-segment elevation (sensitivities of 58% and 56%, respectively) but less specific (specificities of 91% and 93%, respectively). The presence of both a relative lymphocytopenia and an elevated rapid creatine kinase-MB level had a sensitivity of 44%, a specificity of 99.7%, and a positive predictive value of 97% (95% Cl, 80% to 99%). Both a relative lymphocytopenia and an elevated rapid creatine kinase-MB level were independent (P < 0.001) predictors of infarction in patients without ST-segment elevation. If myocardial infarction was suspected by the presence of both abnormal markers or ST-segment elevation, the sensitivity for early diagnosis increased from 39% (ST elevation alone) to 65% (Cl, 52% to 76%); the specificity was 99%; and the positive predictive value was 94% (Cl, 82% to 98%).Conclusions: The presence of both a relative lymphocytopenia and an elevated rapid creatine kinase-MB level was an accurate early marker of myocardial infarction that appeared to improve the sensitivity of early diagnosis compared with that of ST-segment elevation alone. [ABSTRACT FROM AUTHOR]

Red cell morphology as determined by microscopic examination of a stained blood film is an old and traditional approach to the evaluation of an anemic patient. The examination of a well-made and well-stained peripheral blood film remains an important and vital tool in the evaluation of the anemic patient and provides direction for the subsequent laboratory evaluation of the patient's anemia. This article provides a review of the important red cell changes necessary for evaluation in determining the cause of anemia.

Automated image processing analysis for leukocyte differential counting started 30 years ago principally as a mimic of the traditional microscopic method. Several types of systems were used in the 1970s and 1980s. In the late 1990s, two new image processing systems were developed with new technology for cell image analysis. They possess an intelligent neural network software and can be connected to an Ethernet for telehematologic diagnosis and consultation.

The automated hematology analyzer with CBC and differential results has replaced the traditional manual or individual assay methods for hematologic parameters and the eyecount leukocyte differential as the initial screening and detection system for hematologic abnormalities in modern hospitals and clinics. The traditional review of all automated hematology instrument results by preparation, staining, and microscopic examination of a blood film has disappeared in most institutions. The reasons are the more accurate detection of specimens with distributional or morphologic abnormalities by the instruments than by the traditional eyecount method. The opportunity for a clinician to request a microscopic examination of a blood film, whether or not it is flagged, must be preserved, because the clinician's knowledge of the patient's history, physical findings, and current or prior therapy may indicate review to discover an abnormality that may not have been apparent from the instrument results alone. There has also been a dramatic reduction of the numbers of medical technologists and technicians in medical laboratories. Automation of the CBC and differential counts has reduced the number of technologists needed for performance of these tests. But other factors have had a negative effect, such as the necessity to reduce costs. Consolidation of hematology and chemistry laboratories in core laboratories may produce savings in labor costs, but may also create problems of creating and maintaining areas of expertise, such as hematologic morphology, because of the cross-training required and the necessity of personnel to do all things. This article suggests and documents a number of measures that can be infinity stituted by the laboratory and by clinicians to reduce the number of eyecount differentials and blood film reviews that need to be performed. The first effort is to convince clinicians that valid data exist that confirm that a policy of allowing the laboratory to initiate blood film review based on findings of the CBC and automated differential is a more sensitive and accurate method of detecting patients with blood film abnormalities than routine blood film review of all specimens by technologists. Clinicians need to recognize that daily differential results or differentials at intervals of less than a week are not medically necessary in most patients. The laboratory, however, must provide opportunities for the clinician to request differentials at any time for specific medical reasons. The laboratory must establish the validity of screening criteria for detection of distribution and morphologic abnormalities of leukocytes by clinical correlation studies or adopt criteria established by laboratories with the same instrumentation and which have conducted clinical evaluations. A final observation on the eyecount differential is that it was the only way to identify cell types and their relative proportion for nearly 100 years. Cells were identified by their shape, intracellular structures, and staining characteristics. Many studies were able eventually to correlate some aspect of each cell type's function with their morphologic appearance. It has also been learned that the bone marrow is the source of production of most circulating cells and a great deal of the controls of cell production and release into the peripheral blood have been learned. But leukocytes have many functions, almost none of which are performed in the peripheral blood. The peripheral blood is mainly a conduit from the bone marrow to the tissues where the leukocytes perform their function in the case of the neutrophils and monocytes. It is mainly a recirculation and redistribution system for lymphocytes that usually receive their instructions from antigen processing cells in the tissues and allow these modified cells to home to sites where their functions occur. Cellular morphology and staining characteristics tell little about the maturation stage and functional capabilities of leukocytes. One cannot tell the difference between a band and a segmented neutrophil or whether a lymphocyte is a T or B cell on the conventional eyecount differential. One cannot tell the mature granulocyte of a patient with chronic myeloid leukemia from a normal mature neutrophil. Increasingly, techniques are being developed to identify better the maturation stages of cells and association with specific functional capabilities by flow cytometric techniques. The neoplastic nature of some normal-appearing leukocytes can be identified by techniques, such as fluorescent in situ hybridization. With the rapid advances in many approachs to understand the nature and functional capability of leukocytes, the eyecount differential with the traditional Romanowsky stain may be past the apogee of its ascent and beginning its trip into history along with the hemocytometer counting chamber and the Sahli pipet. The development and implementation of new laboratory cornerstone techniques for diagnosis of hematologic disease are eagerly awaited. On the other hand, the red cells and platelets exist to function in the peripheral blood. More emphasis is needed in the development of automated methods of determining the nature and functional capabilities of these true blood cells as part of the CBC.

The eyecount reticulocyte count has been replaced by semi-automated and fully automated methods in laboratories of nearly all developed nations, except for small-volume laboratories and office laboratories in which they are not as cost effective. The eyecount method remains the reference method as defined in NCCLS document H44-A.

We prospectively treated 46 patients with favorable myelodysplastic syndrome classified as refractory anemia (RA), refractory cytopenia (RC), or refractory anemia with ringed sideroblasts (RARS). These patients received one of two schedules of 13-Cis-Retinoic Acid (low dose 80 mg daily for 6 months vs. high dose 200 mg po daily for 3 months), or Danazol (800 mg po daily for 3 months), and were crossed over to the alternative drug in the absence of response or at progression. Using strict criteria of response we found little objective evidence of activity for either compound. Only two minor responses were seen among 22 patients treated with low dose 13-CRA, 1 response among 20 cases that received high dose 13-CRA, and 1 partial response and 1 minor response to Danazol among 34 cases. Neither 13-Cis-Retinoic Acid nor Danazol appear active enough in patients with favorable myelodysplastic syndrome to justify their use.

Three cases of ethylenediamine tetraacetic acid (EDTA)-induced leukoagglutination noted on peripheral blood films are reported. Two cases of EDTA-induced agglutination of benign lymphocytes, and one case of EDTA-induced mature neutrophil satellitosis about immature neutrophil were observed. EDTA-induced agglutination of malignant lymphoid cells has been reported in blood films from patients with malignant lymphoma and chronic lymphocytic leukemia. Our two cases are the first reported instances of EDTA-induced agglutination of benign lymphocytes. EDTA-induced agglutination of neutrophils is a well recognized, but uncommon event. This case was unusual because mature neutrophils were rosetted about a central immature granulocyte and no agglutination of mature neutrophils was noted.

Reticulocyte analysis by flow cytometry offers precision and sensitivity greater than those of conventional morphologic methods and permits derivation of a reticulocyte maturity index. However, interlaboratory variability has not yet been reported. The authors analyzed 310 samples at eight sites using 11 instruments over a 4-month period to examine intermethod and interlaboratory variabilities. Stains included thiazole orange, ethidium bromide, and auramine O. Instruments included models by Coulter, Becton Dickinson, TOA Medical Electronics, and Ortho Diagnostics. The coefficient of variation (CV) among all sites and methods on these samples varied as a function of the reticulocyte percentage, ranging from a mean CV of 69% for samples with < .5% reticulocytes to 24.1% for those with > 2.5% reticulocytes. The best performance was observed with the TOA R-1000 dedicated reticulocyte analyzers, with a mean CV of 18.4% for samples with < .5% reticulocytes and 4.6% for samples with > 2.5% reticulocytes. The reticulocyte maturity index showed comparable intersite precision, with a mean CV of 16% for samples with > 2.5% reticulocytes with multipurpose flow cytometers and a mean CV of 7.3% with the TOA R-1000 instruments. Interclass correlations among all sites ranged from .79 to .99 for the reticulocyte counts and .41 to .88 for the reticulocyte maturity index. The authors conclude that flow cytometric reticulocyte analysis is more precise than manual reticulocyte analysis. With greater automation of this methodology, further interlaboratory standardization of reticulocyte counts and the reticulocyte maturity index can be achieved.

Cytogenetics has provided new insights into the biology and pathogenesis of myelodysplastic syndromes. In patients with refractory anemia, it has provided proof of clonality and has helped differentiate chronic myelomonocytic leukemia from chronic myeloid leukemia. As a prognostic tool, cytogenetics has been predictive of duration of survival and leukemic transformation. However, its role as an independent prognostic factor compared with recent prognostic scoring systems remains to be determined. New techniques such as fluorescent in situ hybridization using chromosome-specific DNA probes may expand the usefulness of cytogenetics. The prognostic impact of cytogenetics may not be fully realized until more effective treatments become available.

The alizarin red S stain for permanent cytologic preparations is a valuable test that is complementary to compensated polarized light microscopic examination to detect calcium crystals. Alizarin red S has the greatest sensitivity for detection of calcium pyrophosphate crystals because crystals are stained regardless of how weakly or strongly birefringent they may be. Alizarin red S stain does not distinguish between amorphous types of calcium compounds; therefore, the different types of calcium compounds can be distinguished only when typical crystal morphologic features are present. Diagnostic importance can be attached to intracellular material that is stainable. In contrast, the diagnostic value of stainable, amorphous, extracellular material is unreliable because it is difficult to distinguish this extracellular material from contaminants frequently found in clinical specimens. Alizarin red S does not stain monosodium urate or corticosteroid crystals. Air-dried cytospin smears are helpful because they may frequently demonstrate more crystals than the wet-mount preparation. Furthermore, special stains can be performed subsequently on air-dried cytospin smears if necessary.

The French-American-British classification scheme of myelodysplastic syndromes includes a category of refractory cytopenia that includes refractory thrombocytopenia (RTC). Because dysmegakaryopoiesis manifesting as an isolated cytopenia can be difficult to identify morphologically and because it may be accompanied by megakaryocytic hyperplasia, RTC may be confused with idiopathic thrombocytopenic purpura. A review of 1,220 cases of myelodysplastic syndromes at Mayo Clinic Jacksonville and Mayo Clinic Rochester from 1979 to 1990 yielded 9 cases (0.7%) of isolated thrombocytopenia (RTC) associated with clonal chromosome abnormalities. Review of 319 marrow chromosome analyses performed at the cytogenetics laboratory at Mayo Clinic Rochester from 1979 to 1990 for patients with low platelet count yielded two additional cases of RTC (0.6%). Of the 11 RTC cases, 3 previously had been misdiagnosed as idiopathic thrombocytopenic purpura. All patients had oval macrocytes in peripheral blood smears and abnormal megakaryocyte morphology in bone marrow aspirates, lacked antiplatelet antibodies, and did not have splenomegaly on clinical examination. The most common clonal chromosome abnormalities involved chromosomes 3, 5, 8, or 20. Steroid therapy was ineffective. Clinical and laboratory findings can establish the diagnosis of RTC and allow the physician to avoid recommending inappropriate therapy (steroids or splenectomy) for these patients.

Evaluation of a prototype Technicon Autoslide, which automatically prepares, fixes, stains, dries labels, and "coverslips" blood films, attached to a Technicon Hemalog D-90 revealed that the instrument prepares high-quality wedge blood smears with uniform distribution of leukocytes, excellent red blood cell and platelet morphology, and adequate staining of normal types of leukocytes. The fixation-staining characteristics did not enable reliable identification of some immature cell types. An additional 200 microliters of blood samples is requred above that required for the Hemalog D-90 in order to prepare a smear. The throughput time of the instrument, from sample aspirate to completion of the blood smear, is 14 min. One sample is completed every 45s. The final glass-slide specimen contains the blood smear sample and its identification and date, embedded in acrylic plastic, which also serves as a coverslip. The instrument can be operated by the D-90 operator with negligible additional effort. The approximate cost of each sample was 8.25 cents. The Autoslide in combination with the Hemalog D-90 should reduce technician time required to prepare, stain, and label blood smears. Its use should reduce the frequency of sample misidentification and provide more uniform quality to slide preparation and staining than is available by current manual techniques. Preliminary studies suggest that Autoslide smears are suitable for use on an image-processing type of automated differential system, and this therefore makes their use possible in a tiered screening system for detection of platelet or red cell abnormalities not recognized by the high-volume cell-counting instruments.

Bone marrow aspirates from 90 patients suspected of having a hematologic disorder were processed by using different cytogenetic methods to determine if any procedure was more likely to reveal a chromosomally abnormal clone or produce better-quality metaphases. All specimens were processed by a direct technique and 24-hr culture without mitogens; 50 specimens were also processed by an amethopterin mitotic synchronization method. In each case, the microscope slides were coded by the processing technologist and analyzed by two other experienced cytogenetic technologists. The results were not known to any of the investigators until all 90 specimens were analyzed. With the exception of one specimen, in which a chromosomally abnormal clone was identified only in the direct preparation, no apparent differences were found in the karyotypes among the three methods. Also, the differences in the quality or number of metaphases found among the three methods were not statistically significant; however, 24-hr unstimulated cultures produced more metaphases than the mitotic synchronization procedure. The greatest source of discordance was caused by one test yielding either no metaphases or an uncertain result when the other tests produced a successful study. We suggest that in routine practice at least two different methods should be used, and it may be best if at least one of these methods is a direct technique.

A retrospective clinical review of 41 patients with chronic myelomonocytic leukemia revealed a median age of 66 years and a male:female ratio of 2.4:1. The disease was preceded by a myelodysplastic syndrome of a different subtype in 24% of the patients and transformed into acute leukemia in 24%. Splenomegaly was present in 54% of the patients and reached massive proportions in 24%. Chromosomal abnormalities occurred in 34% of those studied, most commonly in the younger age group; the most frequent were trisomy 8, monosomy 7, and deletions involving the long arms of chromosomes 20 and X. Polyclonal hypergammaglobulinemia was detected in 47% of the patients in whom serum protein electrophoresis was done. The median survival was 3 years. With use of univariate analysis, the statistically significant prognostic determinants were hemoglobin level, the "modified Bournemouth score," and bone marrow blast cell percentage. When these factors were subjected to a multivariate analysis, only bone marrow blast cell percentage was an independent prognostic determinant. Orally administered hydroxyurea controlled leukocytosis and splenomegaly in some patients without affecting the overall prognosis.

A statistical data processing program for identifying patients who are likely to have abnormalities on various hematologic laboratory tests is described. The prediction of abnormal levels of serum vitamin B12, serum folate, transferrin saturation, and reticulocyte counts is based on a statistical analysis of the patient's age, sex, and routine blood cell measurements. The program was developed using data from normal-value studies and data from patients who had these laboratory abnormalities. The sensitivity and specificity of the program were evaluated in a controlled prospective study of about 5,000 ambulatory adult patients. The program's predictions also were compared with the laboratory tests requested by the patients' attending physicians. The program was most sensitive for predicting low serum vitamin B12 (74%) and low transferrin saturation (78%). In the prospective evaluation, the predictive values varied from 11% for predicting low serum folate to 65% for predicting low transferrin saturation.

The authors compared four leukocyte differential counting methods with the National Committee for Clinical Laboratory Standards Reference Leukocyte Differential Method H20-T to determine the clinical sensitivity of the methods. The three-part differential performed by the Coulter Counter Model S-Plus IV and the Toa E-5000, when combined with instrument flags and defined laboratory checking limits for red blood cell and platelet values, are safe and efficacious screening methods for the presence of morphologic abnormalities. The Geometric Data Hematrak 590 proved comparable in clinical sensitivity to a random 100-cell eye-count differential.

Routine cytogenetic studies were done in 174 consecutive patients with preleukemic or myelodysplastic syndromes (PL/MDS): 5 had the 5q - syndrome, 2 had refractory cytopenia, 43 had refractory anemia, 38 had refractory anemia with ringed sideroblasts, 69 had refractory anemia with excess blasts, 6 had refractory anemia with excess blasts in transition, and 11 had chronic myelomonocytic leukemia. Successful chromosome studies were accomplished in 167 patients (96%); 64 (37%) had a chromosomally abnormal clone. Abnormal clones were most common among patients who had refractory anemia with excess blasts (45%), refractory anemia with excess blasts in transition (60%), and chronic myelomonocytic leukemia (45%); they were least common among patients with refractory anemia (32%) and refractory anemia with ringed sideroblasts (21%). The two patients with refractory cytopenia had normal cytogenetic results. Each patient with the 5q - syndrome had a 5q-chromosome, as this is a prerequisite for the diagnosis. The two most common structural abnormalities were deletion of part of a chromosome 5 long arm (17 patients) and deletion of part of a chromosome 20 long arm (8 patients). Nonspecific structural abnormalities of chromosomes 1, 3, 6, and 17 were also common. The most common numeric abnormalities were monosomy 5 (7 patients), monosomy 7 (4 patients), loss of the Y chromosome (9 patients), and trisomy 8 (20 patients). No chromosome abnormalities were specifically associated with any PL/MDS classification.

Fifty samples of pleural fluid, collected from consecutive patients in a thoracic clinic who had diagnostic thoracentesis, were studied prospectively. Pleural fluid protein was of value in differentiating transudates from exudates. Pleural fluid red cell counts, white blood cell counts, and differential white blood cell counts have no specificity and no usefulness in the differential diagnosis of the origin of the effusion. Pleural fluid cytology was positive in 60% of all the malignancies studied in this series; for the group with metastatic breast carcinoma, there was a 78% positive pleural fluid cytology. Differential white cell counts revealed tumor cells in 45% of malignant effusions. In our experience, the finding of tumor cells is the only useful finding in differential cell counts of the pleural fluid.

A three-phase evaluation of the Toa E-5000 Automated Hematology Analyzer was performed. The first phase consisted of evaluation of linearity, carryover, precisions, accuracy, sample stability, and effectiveness of the mixing and sampling mechanism. The second phase was comparison of erythroid and platelet parameters with results from a Coulter Counter Model S-Plus IV. The third phase consisted of comparison of the trimodal leukocyte differential count of the Toa E-5000 in 300 patients with four other differential methods. The first-phase studies showed excellent performance characteristics. Stability of samples at room temperature was good for a minimum of 12 hours, but storage for longer than 12 hours requires refrigeration to maintain stable values. The erythrocyte and platelet parameters showed good correlation with the Coulter S-Plus IV values except for the erythrocyte distribution width that is calculated differently. The third-phase studies are published elsewhere.

Rapidly fatal acute myelomonocytic leukemia developed in five patients with multiple myeloma who were treated with melphalan for 28 to 54 months. In each patient, multiple myeloma responded to therapy and progress was satisfactory until the development of acute leukemia. At postmortem examination, leukemic infiltration of organs was seen, and there was little or no evidence of myeloma. Consideration of these cases and a review of the literature suggest that these circumstances represent the development of acute myelomonocytic leukemia rather than plasma cell leukemia; there also appears to be an increased incidence of acute leukemia in multiple myeloma, probably related to the alkylating agent.

To better characterize the diagnostic criteria and clinical behavior of malignant histiocytosis, 20 patients treated at the Mayo Clinic during a 25-year period were studied. A wide spectrum of cytologic differentiation was observed, with cells ranging from bland to highly anaplastic; hemophagocytosis was prominent only in conjunction with a bland histologic appearance. In surgical specimens, the diagnosis of malignant histiocytosis necessitated the use of immunoperoxidase methods for lysozyme, immunoglobulin light chain, and alpha-antitrypsin content, as well as cytochemical stains for acid phosphatase and nonspecific esterase. All autopsies showed that organ involvement had varied somewhat from that reported earlier. The correct diagnosis of malignant histiocytosis was made prior to death in only ten of the 20 cases. The mean survival in the 17 fatal cases was 7.6 months; three of the seven patients treated by aggressive chemotherapy achieved complete remission. Relatively longer survival was correlated with initial confinement to the skin and the absence of cytopenia or liver function abnormalities. Three patients with pulmonary involvement from malignant histiocytosis had apparent inappropriate antidiuretic hormone secretion in the absence of central nervous system disease. The accelerated clinical progression of malignant histiocytosis and its response to current chemotherapeutic regimens make rapid diagnosis and familiarity with the pathologic variations seen in this disorder imperative. Routine utilization of special light-microscopic and immunohistochemical stains is mandatory.

Five patients were seen at the Mayo Clinic over an 8-year period with the following complex of clinical and morphologic features; striking eosinophilia, cardiomyopathy, hepatosplenomegaly, and either a rapidly fatal or a prolonged, debilitating illness. In recent years, controversy has raged over the precise designation of this syndrome, with proposals ranging from eosinophilic leukemia to hypereosinophilic syndromes. To focus on the major target organ of the disease, we have favored the term endomyocardiopathy with eosinophilia. Experience with these five patients showed that (1) eosinophilia can persist for many years before symptoms appear; (2) progressive restrictive cardiac disease was the major cause of death and debility; (3) osmiophilic cytoplasmic inclusions are present in eosinophils of these patients and also in cells from other patients with marked eosinophilia; and (4) echocardiography may prove to be a useful noninvasive tool to diagnose and follow the progress of cardiac involvement. Although none of these patients was thought to have leukemia, intensive therapy with steroids or cytotoxic agents, or both, is considered necessary to control the progression of the disease.

Lymphocyte cytotoxicity for target cells is a method for evaluating specific lymphocyte stimulation. In vitro lymphocytotoxicity has been demonstrated in chronic ulcerative colitis and granulomatous colitis, polymyositis and dermatomyositis, systemic scleroderma, recurrent aphthous stomatitis, and periodontal disease. We have investigated lymphocytotoxicity in 36 patients with various oral inflammatory diseases using an automated cell-counting system. This investigation demonstrated in vitro lymphocytotoxicity for gingival epithelial target cells by aggressor lymphocytes harvested from patients with recurrent aphthous stomatitis and periodontal disease. This effect was not seen when the lymphocytes were harvested from normal subjects or from patients with other oral mucosal inflammatory diseases. The automated cell-counting system corresponded very well with the assay technique of exclusion of supravital dye.

An apparently balanced 9;11 reciprocal translocation with break points most likely at 9p22 and 11q24 was found in 3 patients with acute monocytic leukemia [M5 in the French-American-British (FAB) classification schema]. This translocation was not observed in 6 other patients with M5 acute nonlymphocytic leukemia (ANLL) or in chromosome studies on 143 patients with other types of ANLL. This study supports the previously published suggestion that such 9;11 translocations may be associated with some patients with M5 ANLL. In this report, we have also included a patient with M5 ANLL who had an 11;17 translocation with break points apparently at 11q24 and 17q21. Perhaps this is a variant translocation of chromosome No. 11, which may also be associated with monocytic leukemia.

Nine patients with a progressive neurologic disorder that was characterized by mental deterioration, supranuclear vertical gaze paresis, and foam cells or sea-blue histiocytes in the bone marrow are described and compared with patients who were previously described as having " neurovisceral storage disease with vertical supranuclear ophthalmoplegia" and "dystonic lipidosis." The clinical manifestations of our patients and those described by others and the pathologic findings and profiles of lipid analysis reported by others are similar to those in patients with Niemann-Pick disease, type C. Sphingomyelinase activities in leukocytes and skin fibroblasts were normal in our patients and in more than half of the reported cases; these findings are also compatible with those in patients with Niemann-Pick disease, type C. Until the biochemical and genetic abnormalities of Niemann-Pick disease, type C are clearly defined, it is justifiable to classify the disorder under discussion as a subgroup of Niemann-Pick disease, type C because it seems to be a heterogeneous group. From the clinical point of view, the diagnosis is difficult to establish in the absence of abnormalities in the bone marrow in patients who are older than 20 years; repeat examinations of the bone marrow are necessary in such patients. Clinicians should be aware of this disorder not only in patients in the first and second decades of life, when this disorder usually becomes symptomatic, but also in patients in the fourth and fifth decades.

This study consists of 25 patients with chronic granulocytic leukemia in blast crisis (BC) or with acute leukemia who had a Ph1 chromosome and one or more other chromosome abnormalities and who were investigated by cytochemistry and immunocytochemistry techniques to determine whether the predominant blasts were myeloid or lymphoid. The disorder was myeloid in 15 patients, lymphoid in 8, and mixed in 2. Among the 15 patients with myeloid disorders, 13 (86.6%) had an additional Ph1 chromosome, i(17q), +8, +19, or some combination of these abnormalities. None of the eight patients with a lymphoid disorder had +8, +19, or i(17q), but one had an additional Ph1 chromosome. Among the eight patients with lymphoid disorders, two had structural abnormalities of chromosome 7 and two were monosomy 7. None of the patients with myeloid disease had a structurally abnormal chromosome 7, but one was monosomy 7. Our findings suggest that the number of chromosomes in an abnormal clone may be unreliable for distinguishing between lymphoid and myeloid BC. Most patients with myeloid disease had only abnormal metaphases, whereas many patients with lymphoid disorders had both normal and abnormal metaphases. This finding may partially explain why many patients with lymphoid BC respond better to treatment than do those with myeloid BC.

When a low platelet count is unexpected or is unaccompanied by signs or symptoms of hemorrhage, pseudothrombocytopenia should be suspected. The platelet number and morphologic features should be examined on a smear prepared from blood anticoagulated with EDTA. Platelet counts should be repeated either by obtaining a finger-stock specimen with an ammonium oxalate Unopette and counting by phase microscopy or by collecting both an EDTA- and a sodium citrate-anticoagulated venous sample, performing a platelet count on both test tubes, and examining a blood smear from each test tube. If a Coulter Model S Plus IV or V or the Technicon H6000 is used for performance of platelet counts, examination of the histogram display of the Coulter instrument or the peroxidase X-Y display of the Technicon H6000 should alert the instrument operator to the presence of EDTA-induced platelet clumping and prevent the reporting of a spuriously low platelet count.

There appear to be four primary areas of interest in the application of cytogenetic techniques to the study of malignant lymphomas: (1) the role of cytogenetics in the diagnosis of lymphoma in problem cases, (2) as an aid to the classification of malignant lymphomas, (3) whether specific chromosomal patterns will have prognostic significance for response to therapy or survival, and (4) the role of cytogenetics in staging of malignant lymphomas. A case of reactive lymphoid hyperplasia is reported in which cytogenetic studies demonstrated an aneuploid clone suggesting that cytogenetic abnormalities of lymphoma may precede the diagnostic histopathologic picture. The occurrence of 14q+ marker chromosomes in plasmacytic myeloma, plasma cell leukemia, malignant lymphomas, Burkitt's lymphoma, and ataxia-telangiectasia suggest that a common etiologic or pathogenetic mechanism may be present in some of these disorders. A preliminary pilot study of spleens removed at staging laparotomy for Hdgkin's disease suggests that cytogenetic studies may be able to detect Hodgkin's disease that is not apparent histologically. Further studies are required to provide answers to these areas of interest in cytogenetics in malignant lymphoma.

Chronic lymphocytic leukemia rarely develops an acute blastic phase as a terminal complication. When it does, the blastic phase is characterized by the appearance of large, immature cells with the same immunologic markers as the cells in the chronic phase of chronic lymphocytic leukemia; this coexistence of mature lymphocytes and blastic forms in chronic lymphocytic leukemia has been termed "Richter's syndrome." In a patient of ours with chronic lymphocytic leukemia, the development of a presumed large cell lymphoma was recognized on both bone marrow aspiration and biopsy examination, but later the condition was proved to be a true histiocytic neoplasm (malignant histiocytosis) by cytochemical and immunohistochemical techniques. We are unaware of another reported instance of malignant histiocytosis as a terminal complication of chronic lymphocytic leukemia and mimicking Richter's syndrome.

Immunocytochemical methods were evaluated in order to find a practical one for cell identification on cytologic preparation of body fluids. The effects of fixatives and Triton X-100 treatment on the preservation of cell-type-specific antigens and cell morphologic characteristics were also examined. The method using the alkaline phosphatase-antialkaline phosphatase (APAAP) complex as the indicator is recommended because of its high specificity and sensitivity. With this method, currently available and potentially useful monoclonal antibodies were examined, and the antibodies that were useful for the identification of normal and neoplastic cells commonly present in body fluids were selected for practical applications.

A case of giant cell arteritis is reported that was detected by bone marrow biopsy. The histopathologic features of the bone marrow lesion included an enlarged artery, whose wall showed intimal thickening, fibrinoid necrosis, destruction of the internal elastic lamina, and multinucleated giant cells. The demonstration of involvement of bone marrow vessels by giant cell arteritis reaffirms the systemic nature of the disease. Bone marrow biopsy is not the method of choice for establishment of the diagnosis of giant cell arteritis, but it may lead to the diagnosis in rare instances.

Clinical, hematologic, and prognostic differences between Philadelphia chromosome (Ph1)-positive and Ph1-negative chronic granulocytic leukemia (CGL) have been described. However, Ph1-negative disease may be a mixture of other entities. The authors identified 24 patients given the diagnosis of Ph1-negative CGL after evaluation by the Hematology Department of the Mayo Clinic between January 1976 and August 1984. Each patient was Ph1-negative, and a bone marrow examination was interpreted as CGL. Initial peripheral blood and bone marrow samples were available for review in 22 patients. Their disorders were reclassified as chronic myelomonocytic leukemia (13 patients), chronic myelomonocytic leukemia in transformation (1 patient), preleukemic syndrome (3 patients), and undifferentiated chronic myeloproliferative disease (5 patients). Median survival for the 22 patients was 17 months.

Prior electron microscopic studies have suggested that immature eosinophils degranulate during normal maturation in human bone marrow. This hypothesis was tested by measuring levels of eosinophil granule major basic protein (MBP) and Charcot-Leyden crystal (CLC) protein in bone marrow sinusoidal blood. MBP and CLC protein levels were elevated initially in bone marrow sinusoidal blood from normal volunteers when compared with peripheral blood, and levels of both proteins decreased during serial sampling; CLC protein levels remained significantly elevated, while MBP levels declined to equal those of peripheral blood. To investigate whether MBP and CLC protein were secreted during eosinophil maturation, bone marrow cells were cultured in soft agar; MBP and CLC protein levels were measured in culture supernatants by RIA. There was a significant positive correlation between eosinophil colony growth and levels of each protein. Electron micrographs of cells in soft agar colonies provided ultrastructural evidence for secretion of granule products by immature eosinophils. These results support prior observations that eosinophil promyelocytes degranulate during maturation.

Thirty children with previously untreated acute lymphoblastic leukemia were studied prior to therapy to determine whether sheep erythrocyte (E)-receptor status correlated with clinical factors, cytochemical staining characteristics, FAB morphologic classification, and karyotype. Five patients (17%) with more than 50% E+ blasts had intense focal acid phosphatase staining and distinct clinical characteristics, including high leukocyte counts, mediastinal masses, and involvement of the central nervous system at diagnosis. Focal acid phosphatase activity was present in blasts of patients with greater than 20% E+ blasts, but this group had fewer poor risk factors. Morphologic and karyotypic features were not related to erythrocyte-receptor status, but the L2 morphologic appearance occurred more frequently in older patients (P less than 0.05). Erythrocyte receptors have both qualitative and quantitative clinical correlations in childhood acute lymphoblastic leukemia; however, E+ and E- groups are heterogeneous and E+ groups must be analyzed for other risk factors and relapse rates determined before firm conclusions can be made about erythrocyte rosetting as an independent risk variable.

A method for identifying monocytes by the "non-specific esterase" stain is described. This method is particularly applicable to mononuclear cell suspensions obtained by Ficoll--Hypaque density gradient separations and allows rapid as well as accurate determinations.

Platelet satellitosis resulted in an elevated high-peroxidase-activity value (9.9% versus normal range 0 to 3.65%) of the automated leukocyte differential count performed by the Technicon Hemalog D. Platelet satellitism occurred in Wright-stained smears of EDTA-anticoagulated blood, as well as in the effluent of the peroxidase channel of the Hemalog D. All platelets took up the perosidase stain. The rosette-like clusters of platelets and neutrophils were interpreted as single, large, intensely stained leukocytes resulting in the elevated high-peroxidase-activity value.

A study was made of the routine electronic measurements of erythrocyte size and hemoglobin concentration in blood samples from 122 patients with decreased transferrin saturation and 66 patients with elevated levels of hemoglobin A2 or F. The medical histories of these patients were reviewed to identify 52 cases of uncomplicated iron-deficiency anemia and 39 cases of uncomplicated thalassemia minor. Four decision functions were compared for separating these two disorders. The functions evaluated were: D.F'. = MCV--[5 X Hb]-RBC; ratio MCV/RBC; ratio MCH/RBC, and RBC. The rules performed better in the uncomplicated cases than in the routine laboratory defined cases. Only minor differences in the performances of the various decision functions were observed. None was sufficiently accurate for final diagnosis, but they should have value in screening patients and in determining which additional test should be considered.