Deep learning for diagnosis and survival prediction in soft tissue sarcoma

BACKGROUND

Clinical management of soft tissue sarcoma (STS) is particularly challenging. Here, we used digital pathology and deep learning (DL) for diagnosis and prognosis prediction of STS.

PATIENTS AND METHODS

Our retrospective, multicenter study included a total of 506 histopathological slides from 291 patients with STS. The Cancer Genome Atlas cohort (240 patients) served as training and validation set. A second, multicenter cohort (51 patients) served as an additional test set. The use of the DL model (DLM) as a clinical decision support system was evaluated by nine pathologists with different levels of expertise. For prognosis prediction, 139 slides from 85 patients with leiomyosarcoma (LMS) were used. Area under the receiver operating characteristic (AUROC) and accuracy served as main outcome measures.

RESULTS

The DLM achieved a mean AUROC of 0.97 (±0.01) and an accuracy of 79.9% (±6.1%) in diagnosing the five most common STS subtypes. The DLM significantly improved the accuracy of the pathologists from 46.3% (±15.5%) to 87.1% (±11.1%). Furthermore, they were significantly faster and more certain in their diagnosis. In LMS, the mean AUROC in predicting the disease-specific survival status was 0.91 (±0.1) and the accuracy was 88.9% (±9.9%). Cox regression showed the DLM's prediction to be a significant independent prognostic factor (P = 0.008, hazard ratio 5.5, 95% confidence interval 1.56-19.7) in these patients, outperforming other risk factors.

CONCLUSIONS

DL can be used to accurately diagnose frequent subtypes of STS from conventional histopathological slides. It might be used for prognosis prediction in LMS, the most prevalent STS subtype in our cohort. It can also help pathologists to make faster and more accurate diagnoses. This could substantially improve the clinical management of STS patients.

[Granular-cell tumor (Abrikossoff's tumor): precise preoperative diagnosis is crucial when for minimally-invasive resection]

HISTORY AND ADMISSION FINDINGS

A 38-year-old man was referred to a gastroenterologist because of thoracic pain and dysphagia of uncertain cause.

INVESTIGATIONS

Endoscopy revealed a centrally depressed, coarse submucosal tumor, 1.0 cm in diameter, in the anterior wall of the esophagus at about 35 cm from the teeth. Button-hole biopsy revealed histologically and immunohistochemically a granular cell tumor (Abrikossoff's tumor), positive for S-100 protein. CT-staging was unremarkable, except for a thickening of the distal esophageal wall.

TREATMENT AND COURSE

Minimally invasive submucosal resection was undertaken using the videoscopic/endoscopic rendezvous technique. Histological examination confirmed complete resection of the tumor. The clinical course was uneventful and endoscopy 6 and 12 weeks after the operation showed complete resection of the tumor.

CONCLUSION

An exact preoperative diagnosis beyond a mere description of site and morphology, but also providing the histopathological data creates favorable conditions for planning and performing a minimally invasive resection. Submucosal resection with the videoscopic/endoscopic in rendezvous technique offers the possibility of complete resection, which can often not be achieved in a submucosal tumor by only endoscopic resection.

MRI of a microcystic adnexal carcinoma of the skin mimicking a fibrous tumour: case report and literature review

Microcystic adnexal carcinoma of the skin is a very rare malignant tumour arising from the sweat glands. As far as we know, the MRI features of this tumour have not been described in the literature before. In this report we present the MRI features and pathological description of a case of a microcystic adnexal carcinoma in the cheek that was incidentally imaged during brain MRI examination. A review of the relevant literature as well as a discussion of MRI of skin tumours is also presented.

6-18F-fluoro-L-dihydroxyphenylalanine positron emission tomography is superior to 123I-metaiodobenzyl-guanidine scintigraphy in the detection of extraadrenal and hereditary pheochromocytomas and paragangliomas: correlation with vesicular monoamine transporter expression

CONTEXT

Pheochromocytomas (PHEOs) and paragangliomas (PGLs) may be better detected by (18)F-fluorodihydroxyphenylalanine-positron emission tomography (FDOPA-PET) than (123)I-metaiodobenzyl-guanidine (123-I-MIBG) scintigraphy.

OBJECTIVE

The objective of the study was to correlate functional imaging results with immunohistochemical, molecular-genetic, and biochemical findings.

DESIGN AND SETTING

Thirty consecutive patients with suspected PHEO/PGL presenting at a tertiary referral centre were investigated in a prospective study.

PATIENTS

Twenty-five patients had confirmed PHEO/PGL. Thirteen of 25 patients had a hereditary PHEO/PGL syndrome (two multiple endocrine neoplasia II, six succinate dehydrogenase complex, subunit D, two succinate dehydrogenase complex, subunit B, one von Hippel Lindau tumor suppressor protein, two Neurofibromatosis-1), and 12 of 25 were classified as sporadic. Five patients had hormonally inactive adrenal incidentalomas.

MAIN OUTCOME MEASURES

In all patients computed tomography scan and/or magnetic resonance imaging as well as both 123-I-MIBG scintigraphy and FDOPA-PET were performed. Resected tumors were examined by immunohistochemistry for expression of the vesicular monoamine transporter (VMAT)-1 and -2 and other markers.

RESULTS

A total of 64 lesions were found with both functional imaging modalities. FDOPA-PET detected 62 lesions, whereas only 34 lesions were detected by 123-I-MIBG scintigraphy. This resulted in an overall sensitivity and specificity for FDOPA-PET of 98 and 100% and for MIBG of 53 and 91%, respectively. Comparable sensitivities were found for adrenal and extraadrenal abdominal lesions (94 vs. 97%), whereas in thoracic/cervical lesions, the sensitivity for 123-I-MIBG scintigraphy (15%) was inferior to that of FDOPA-PET imaging (100%). Immunohistochemistry demonstrated a lack of VMAT-1 expression in all MIBG-negative tumors. Clinical predictors for MIBG negativity were a predominant norepinephrine/normetanephrine secretion, an age less than 45 yr, and a hereditary cause.

CONCLUSION

FDOPA-PET is superior to 123-I-MIBG scintigraphy in patients with extraadrenal, predominantly noradrenaline-secreting, and hereditary types of PHEO/PGL. The lack of VMAT-1 expression predicts negativity for MIBG-scintigraphy.

Misleading initial histological diagnosis of a polymorphous low-grade adenocarcinoma in situ ex pleomorphic adenoma-a case report

INTRODUCTION

Polymorphous low-grade adenocarcinoma (PLGA) are frequent tumours of palatinal minor salivary glands. They appear clinically as solid mass located beneath intact surface epithelium, thus quite similar with benign neoplasm. PLGA displays a low tendency of aggressive behaviour. The correct aetiology of this disorder is still unknown.

CASE REPORT

In this contribution, a PLGA is reported which was located in a pleomorphic adenoma (PA). Out of an initially incisional biopsy, only the benign part of the lesion was diagnosed. Definitive histological examination of the whole tumour revealed a small malignant fraction of the specimen besides a major part of benign tissue formations (PA).

CONCLUSION

This case shows the uncertain confidence of incisional biopsy, the variably biologic behaviour of PA, providing hints for consideration of the PLGA aetiology and highlights both the necessity to remove whole PA-like lesions as well as to perform systematically histological examination of whole specimens.

On the optimization of the isotopic neutron source method for measuring the thermal neutron absorption cross section: advantages and disadvantages of BF3 and 3He counters

The effect of the detector characteristics on the performance of an isotopic neutron source device for measuring thermal neutron absorption cross section (Sigma) has been examined by means of Monte Carlo simulations. Three specific experimental arrangements, alternately with BF(3) counters and (3)He counters of the same sizes, have been modelled using the MCNP-4C code. Results of Monte Carlo calculations show that devices with BF(3) counters are more sensitive to Sigma, but high-pressure (3)He counters offer faster assays.

'The measurement of thermal neutron flux depression for determining the concentration of boron in blood'--suggestions as to further development of the method

Suggestions about determining the concentration of 10B in blood via the thermal neutron flux depression measurement (NFDM) are made. The use of a measuring set-up consisting of a 252Cf neutron source, polyethylene moderator and a slim BF3 counter surrounded by an annular sample is examined. It is shown experimentally that using 6 ml samples and the source emitting 1.4 x 10(7) neutrons s(-1), one can determine the concentration of 10B in water at the level of 10 ppm with a statistical precision of 10% in about 20 min. Monte Carlo simulations performed with the use of MCNP-4C code revealed a potential for further improvements of the NFDM technique both in respect of the sample volume and counting period.

[Cystic myoepithelioma. A rare differential diagnosis of a cystic lesion of the parotid gland]

By sonography, we found a sharply demarcated tumor with cystic areas in the parotid gland of a 41 year old male, indicating Warthin's tumor. Subtotal parotidectomy was performed. Microscopy showed an encapsulated tumor with myoepithelial cells and, in particular, central pseudocysts. Immunohistochemically, the tumor cells expressed cytokeratin 5/6 and S-100 protein as well as smooth muscle-actin. These features led to the diagnosis of a cystic myoepithelioma. Histopathologically, several different lesions of the salivary glands should be considered in the differential diagnosis of myoepithelioma, especially of this hitherto unique case in the parotid gland. The differential diagnoses are reviewed and discussed. Treatment is by surgical resection. Because of the tendency of myoepitheliomas to recur and to malignant transformation, tumor-free margins are recommended.

Chronic idiopathic myelofibrosis: prognostic impact of myelofibrosis and clinical parameters on event-free survival in 122 patients who presented in prefibrotic and fibrotic stages. A retrospective study identifying subgroups of different prognoses by using the RECPAM method

In chronic idiopathic myelofibrosis (CIMF) the factors predicting survival in patients who were already in the fibrotic stage have been well documented by numerous studies. Prefibrotic stages were only rarely evaluated so that the prognostic impact of myelofibrosis is currently not well known. Also predictive factors for disease-related events were not included in those studies. Thus, we evaluated the prognostic impact of myelofibrosis and other histopathological (megakaryocytes, blasts) and clinical [age, gender, splenomegaly, chemotherapy, hemoglobin (Hb), leukocyte, and platelet count] parameters in 122 patients in fibrotic and prefibrotic stages of CIMF on event-free survival. The statistical analysis was performed using the univariate log-rank test and the multivariate recursive partition and amalgamation (RECPAM) approach. In 62 patients disease-related events occurred during a mean observation period of 58 months. In univariate analysis they were associated with blast increase in the bone marrow. In RECPAM analysis a shorter event-free survival was found in anemic patients (mean: 9.3 months). In nonanemic patients older than 60 years, advanced myelofibrosis was associated with a shorter event-free mean survival of 23.2 months versus 69.3 months in less advanced cases. A slight or moderate myelofibrosis was not found to have a prognostic impact on event-free survival. The longest event-free survival was found in nonanemic patients who were younger than 60 years (mean: 185 months), regardless of the grade of myelofibrosis. Thus, we found that the most relevant prognostic parameter for event-free survival in CIMF were the Hb value, age, and grade of myelofibrosis.

[Incidence and differential diagnosis of chronic eosinophilic leukemia]

The diagnosis of chronic eosinophilic leukemia (CEL) is based on the evidence of an autonomous, clonal proliferation of eosinophilic precursors and the exclusion of other myeloid neoplasms with eosinophilia. Histopathological evaluations of bone marrow are rare, and reliable data on the frequency of CEL do not yet exist. A total of 100 cases characterized by eosinophilia >/=1.5x10(9)/l blood for more than 6 months were evaluated. In 87 cases, the eosinophilia turned out to be secondary and a reactive genesis was likely, but not proven in 3 further cases. Idiopathic hypereosinophilic syndrome was diagnosed in three cases. The diagnosis CEL was considered in four out of a total of seven cases with a myeloid neoplasia and all four disorders showed an abnormal karyotype. However, only one of them could be classified as CEL. We conclude that CEL is a rare disease concerning only a minority of cases with chronic eosinophilia.

[The development of myelofibrosis in prefibrotic cIMF. An investigation of the progression by sequential bone marrow biopsies in 38 patients]

Overt myelofibrosis in bone marrow biopsies as a diagnostic postulate in cIMF has been discarded only recently by the WHO. Therefore, only a few studies have been performed on the evolution of myelofibrosis in "prefibrotic" cIMF by means of sequential bone marrow biopsies. We carried out this study on 38 patients, split up into two groups, A and B according to treatment modalities, to evaluate the dynamics and frequency of myelofibrosis in both groups. Our results indicate a step-wise development of myelofibrosis from a "prefibrotic" to a "classical" cIMF, as 75-80% of the respective patients in both groups progressed to myelofibrosis. However, this evolution seems to be heterogeneous and unpredictable in individual patients, since myelofibrosis could be seen as early as less than 2 years after diagnosis in 12/38 (31.6%) patients, whereas 3 patients remained "prefibrotic" even after up to 6 years of follow-up.

[Growth of a squamous epithelial carcinoma in an odontogenic cyst]

Malignant change in the epithelium of an odontogenic cyst and growth of an invasive squamous cell carcinoma is rare. The diagnosis of malignant disease is mostly only established by histological evaluation of excised tissue because the initial clinical appearance does not differ much from that of odontogenic cysts. The clinical course of one patient after removal of an impacted canine and adjacent cystic tissue is presented. Histological evaluation of the specimen led to diagnosis of a squamous cell carcinoma arising from the cystic epithelium. Partial resection of the maxilla was performed subsequently and 1 year postoperatively the patient was free from recurrence or metastasis. This case report underlines the importance of submitting any soft tissue excised in the treatment of odontogenic cysts to histologic evaluation.

Fibre content and cellularity of the bone marrow of the iliac crest, vertebral column and sternum in chronic myeloproliferative disorders

Heterogeneous content of fibres and haematopoesis within the bone marrow may affect diagnosis and staging in chronic myeloproliferative disorders (CMPDs). To evaluate their distribution, we conducted a post mortem histomorphometric study of 22 patients with CMPD in chronic phases. In bone marrow specimens from the anterior and posterior iliac crest (right and left of each), the sternum, the 7th thoracic and the 3rd lumbar vertebra, the argyrophil fibres were counted using the line intersection method and the cellular and fatty bone marrow using the point count method. Statistical analysis was performed by direct comparison of the sites. The distribution of fibres was almost homogeneous in the patients with low fibre content, revealing a random diversity in more advanced stages of marrow fibrosis. 1/22 patient had no fibre increase in one specimen of the iliac crest and overt myelofibrosis in the other sites. 1/22 patient had myelofibrosis in two sites of the iliac crest and no fibre increase in vertebral column and sternum. The bone marrow cellularity was almost homogeneously increased in all patients. Myelofibrosis proved to be a generalised process with heterogeneous grades of severity in different regions of the bone marrow in CMPDs. No topographical bias was found. In contrast to the homogeneous increase of the bone marrow cellularity the topographical heterogeneity of the fibre content may limit the representativity of single bone marrow biopsies in patients with CMPDs.

Anaerobic nitrate reductase (narGHJI) activity of Mycobacterium bovis BCG in vitro and its contribution to virulence in immunodeficient mice

Mycobacterium tuberculosis and Mycobacterium bovis cause tuberculosis, which is responsible for the deaths of more people each year than any other bacterial infectious disease. Disseminated disease with Mycobacterium bovis BCG, the only currently available vaccine against tuberculosis, occurs in immunocompetent and immunodeficient individuals. Although mycobacteria are obligate aerobes, they are thought to face an anaerobic environment during infection, notably inside abscesses and granulomas. The purpose of this study was to define a metabolic pathway that could allow mycobacteria to exist under these conditions. Recently, the complete genome of M. tuberculosis has been sequenced, and genes homologous to an anaerobic nitrate reductase (narGHJI), an enzyme allowing nitrate respiration when oxygen is absent, were found. Here, we show that the narGHJI cluster of M. tuberculosis is functional as it conferred anaerobic nitrate reductase activity to Mycobacterium smegmatis. A narG mutant of M. bovis BCG was generated by targeted gene deletion. The mutant lacked the ability to reduce nitrate under anaerobic conditions. Both mutant and M. bovis BCG wild type grew equally well under aerobic conditions in vitro. Histology of immunodeficient mice (SCID) infected with M. bovis BCG wild type revealed large granulomas teeming with acid-fast bacilli; all mice showed signs of clinical disease after 50 days and succumbed after 80 days. In contrast, mice infected with the mutant had smaller granulomas containing fewer bacteria; these mice showed no signs of clinical disease after more than 200 days. Thus, it seems that nitrate respiration contributes significantly to virulence of M. bovis BCG in immunodeficient SCID mice.

Polycythaemia vera: bone marrow histopathology under treatment with interferon, hydroxyurea and busulphan

Little is known about long-term effects of myelosuppressive therapy on bone marrow of patients with polycythaemia vera, since histopathology from follow-up biopsies has not been frequently reported. Thus we conducted a retrospective morphometrical analysis of diagnostic and follow-up biopsies of 62 patients, evaluating fibre content, megakaryocytes and bone marrow cellularity. 8/62 patients were treated with interferon-alpha (INF), 11/62 with hydroxyurea (HU) and 11/62 with busulphan (BU). 32/62 served as controls; they were not treated with myelosuppressive drugs but with phlebotomy only. The median observation time was 2.3 yr. Results were compared on the basis of change per time. The bone marrow of the patients with phlebotomies only was characterised by increasing cellularity of haematopoesis, number and volume ratio of megakaryocytes and fibre content. In BU- and HU-treated patients, the haematopoesis was significantly reduced. The IFN patients revealed a reduction of cellularity which was not significant. The fibre content was reduced by BU only, but not significantly. No correlation between megakaryocytes and fibres was found. It could be concluded therefore that: 1) fibre proliferation within the bone marrow was not significantly altered by IFN, HU or BU. 2) Cellularity of haematopoesis was reduced significantly by HU and BU but only partly by IFN, corresponding with haematological remission.

Characterization of a murine model of melioidosis: comparison of different strains of mice

Melioidosis is an infectious disease caused by the saprophytic gram-negative rod Burkholderia pseudomallei. The aim of this study was to establish and characterize a murine model of melioidosis to provide a basis for further investigations on the pathogenesis of the disease. After intravenous infection with B. pseudomallei, C57BL/6 mice were found to be significantly more resistant than BALB/c mice. There was a marked organotropism of B. pseudomallei for the spleen and liver in both strains of mice, with the highest bacterial load in the spleen. Electron microscopic investigations of the spleen clearly demonstrated intracellular replication within membrane-bound phagosomes. Electron micrographs of the liver provided evidence that B. pseudomallei-containing phagosomes in hepatocytes fuse with lysosomes, leading to degradation of bacteria. In both strains of mice, the course of infection was highly dependent on the infective dose and the bacterial strain used, ranging from death within a few days to death after several weeks. In comparison with BALB/c mice, the bacterial counts in C57BL/6 mice were decreased 12 h after infection, which is suggestive of an innate immune mechanism against B. pseudomallei in this early phase of infection contributing to the lower susceptibility of C57BL/6 mice. BALB/c mice developed a more pronounced lymphopenia, granulocytosis, and splenomegaly at a lower infective dose compared to C57BL/6 mice. Analysis of the antibody response against B. pseudomallei 11 days after infection revealed a significantly higher immunoglobulin G2A (IgG2a)/IgG1 ratio in C57BL/6 mice than in BALB/c mice, indicating that a T helper type 1 immune response is associated with resistance to infection with B. pseudomallei.

Molecular detection of c-mpl thrombopoietin receptor gene expression in chronic myeloproliferative disorders

BACKGROUND

Chronic myeloproliferative disorders (CMPD) originate from a pluripotent haematopoietic progenitor cell but show a marked degree of heterogeneity, especially between Philadelphia chromosome positive and negative disease entities. Abnormal megakaryopoiesis is a frequent finding in CMPD, often associated with thrombocythaemic cell counts. Recent experimental data have suggested that the c-Mpl thrombopoietin receptor, together with its ligand thrombopoietin, are not only the major physiological regulators of megakaryopoiesis and platelet production, but also play a crucial role in chronic myeloproliferation.

METHODS

A total of 18 peripheral blood mononuclear cell samples obtained from patients with CMPD (chronic myelocytic leukaemia (CML), n = 10; polycythaemia vera (PV), n = 6; and primary thrombocythaemia (PTH), n = 2) were analysed for c-mpl mRNA using the reverse transcriptase polymerase chain reaction (RTPCR). In another 20 patients (CML, n = 10; chronic megakaryocytic granulocytic myelosis (CMGM), n = 3; PV, n = 3; PTH, n = 4), we compared the number of haematopoietic progenitors expressing c-Mpl, as characterised by coexpression with the CD34 antigen, in the bone marrow using double immunofluorescence staining.

RESULTS

c-mpl mRNA was detected in all samples from patients with CML analysed, whereas only two of six PV and one of two PTH samples were positive (p < or = 0.008; chi 2 test). Expression of the c-mpl receptor gene was absent in healthy subjects used as controls. Similarly, an increase of c-Mpl expressing CD34 positive haematopoietic cells was detected in seven of 10 bone marrow aspirates obtained from patients with CML. Increased numbers of c-Mpl positive CD34 positive cells were found in only one of four patients with PTH, whereas in PV and CMGM the numbers of c-Mpl positive CD34 positive cells did not exceed normal values, despite thrombocythaemic cell counts.

CONCLUSIONS

These data confirm recent findings showing an impaired expression of the c-mpl thrombopoietin receptor gene in Philadelphia chromosome negative CMPD when compared with patients with Philadelphia chromosome positive CML. The relevance of this observation to the functional and morphological characteristics of abnormal megakaryopoiesis remains unclear. Thrombocythaemic cell counts and a mature phenotype in megakaryocytes occur frequently in Philadelphia chromosome negative CMPD but require an intact c-Mpl receptor under physiological conditions. Therefore, further studies are warranted to elucidate the mechanisms contributing to megakaryopoiesis in CMPD disease entities with decreased c-mpl gene expression.

WY-50295 tromethamine: a 5-lipoxygenase inhibitor without activity in human whole blood

The 5-LO inhibitor, WY-50295 tromethamine (T) prevented leukotriene release (LTB4 production) in calcium ionophore stimulated, purified human and rat neutrophils. However, whereas WY-50295T inhibited both in vitro and ex vivo rat whole blood leukocyte LTB4 formation (IC50= 40 microM and oral ED50 of 18 mg/kg, respectively), it did not inhibit LTB4 production in calcium ionophore stimulated human whole blood at concentrations to 200 microM. To reduce binding of WY-50295T to serum albumin, 250 microM of a naphthalene sulfonic acid (> 99.9% binding to albumin primarily at the carboxylic site) and 250 microM sulfanilamide (binding to nonspecific sites) separately or in combination were preincubated in whole blood prior to addition of WY-50295T; however, WY-50295T still did not inhibit 5-LO and free drug blood levels were unchanged. When purified human neutrophils in the presence of fatty acid saturated albumin (fraction V) was employed, the 5-LO inhibitory activity of WY-50295T was prevented. Zileuton (5 microM) inhibited LTB4 production by 99% in the presence of these albumins. Also, rat albumin presented WY-50295T to purified rat neutrophils more effectively than human albumin (i.e. WY-50295T was more active in the presence of rat albumin). These results suggest that the high affinity binding of WY-50295T to human albumin and possibly the reduction of drug uptake (passive diffusion) using purified human vs rat neutrophils may account for the inactivity of WY-50295T in the human whole blood assay.

The histopathology of chronic myeloproliferative diseases

This chapter discusses the histopathology of five groups of chronic myeloproliferative diseases: chronic myeloid leukaemia, polycythaemia vera, essential thrombocythaemia, chronic idiopathic myelofibrosis and unclassifiable myeloproliferation. Histological staging of the four haematologically defined diseases is performed by grading the three most prominent variables: megakaryocytes, fibres and blasts. Histological outcome is correlated to the staging of diagnostic bone marrow biopsies; megakaryocytic involvement is correlated with the risk of myelofibrosis. An excess of blasts is related to the risk of leukaemic transformation. The progression of myelofibrosis depends on the grade of fibre increase at diagnosis. These three statements are highly significant and valid for all types of chronic myeloproliferative disorders. The results of cytogenetics are discussed in relation to the histological classification for these patient groups. Changes in bone marrow histology following myelosuppressive therapy is presented. Prospective studies under standardized protocol therapy are recommended, so that the long-term effects of therapy can be assessed.

Immunophenotype of hairy-cell leukaemia after cold polymerization of methyl-methacrylate embeddings from 50 diagnostic bone marrow biopsies

Hairy-cell leukaemia may be difficult to diagnose in bone marrow biopsies, especially in the early stages or in its residum after complete clinical remission. To consider the impact of published data on immunophenotyping hairy-cell leukaemias, a total of 50 diagnostic biopsies were systematically analysed with a panel of eight antibodies and compared with cases of chronic lymphatic leukaemia (CLL), 20 follicular centre lymphomas, 20 lympho-plasmacytoid immunocytomas, 10 small-cell T-cell non-Hodgkin lymphomas and 20 cases of benign nodular lymphatic hyperplasia. The panel of eight antibodies comprised DBA44, CD45, CD20, CD45R, CD45RO, CD43 and the CD68 antibodies KP1 and Ki-M1P. The hairy-cell leukaemias were staged histologically into four categories of bone marrow infiltration. DBA44 reacted positively in 47/50 cases. CD45 and the B-cell markers CD20 and CD45R reacted in 49/50 and 43/50 cases, respectively. One CD68 marker, KP1, was positive in 38/50 cases but the other-Ki-M1P-only in 1/50 cases. Chronic lymphatic leukaemia cases, the other B-cell NHLs and lymphatic hyperplasias showed strong positivity for CD20 and CD45R, but only the immunocytomas reacted with DBA44 in 7/20 cases. The T-cell NHLs and hyperplasias showed a strong positivity for the T-cell markers CD45RO and CD43. The CD68-marker Ki-M1P revealed a high specificity since it was negative in all NHLs and positive only in one hairy-cell leukaemia. Methyl-methacrylate embedding of bone marrow biopsies under cold polymerization produces a high quality of histo- and cytomorphology, resulting in greater diagnostic reliability and the detection of low-stage infiltration of hairy-cell leukaemia. DBA44 appears as a highly specific antibody to mark hairy-cells since only immunocytomas reacted positively in a few cases. A small panel of antibodies including DBA44. CD20, CD45R and Ki-M1P may serve to distinguish small-cell. NHL from hairy-cell leukaemia even at an early stage or when there are minimal residual tumour cells.

Classification and staging of Ph-negative myeloproliferative disorders by histopathology from bone marrow biopsies

The present study illustrates characteristic features of histopathology in the 3 non-leukemic, Ph-negative groups of chronic myeloproliferative diseases (CMPD). Attention is paid to the final outcome of CMPD, especially its transformation into acute leukemias and the occurrence of myelofibrosis from bone marrow biopsies (BMB) in a total of 1,716 CMPD patients. Essential thrombocythemia (ET), polycythemia vera (P. vera), and chronic megakaryocytic granulocytic myelosis (CMGM) can readily be distinguished by histopathology from BMB in the great majority of patients without regarding laboratory data, leaving a compartment of about 12% unclassifiable cases. Histologic patterns of staging are the increase in number and pleomorphism of megakaryocytes (MK), increase in number and density of reticulin fibers and collagen fibrosis, and excess of blasts. These 3 criteria are each graded from 0 to 3 in every biopsy. From these, a staging results by means of the histology of BMB in each of the Ph-negative CMPD. This staging provides a classification by defined criteria which permits comparative studies, the possibility of monitoring the individual patients by follow-up histology, and offers a baseline for reliable evaluation of results from therapy protocols.

[DDD versus DDDR pacemaker stimulation: comparison of cardiopulmonary performance, incidence of atrial arrhythmias and quality of life]

The purpose of this study was to assess cardiopulmonary exercise capacity, variation in heart rate during everyday activities, frequency of atrial arrhythmias and quality-of-life during accelerometer-based rate modulated dual-chamber pacing. Nine chronotropically incompetent and 14 chronotropically competent patients (mean age 51 years) were randomly assigned to DDD and DDDR mode and evaluated by a semisupine bicycle exercise testing exceeding the anaerobic threshold, 24-h Holter monitoring and a quality-of-life questionnaire. In the subgroup of patients with chronotropic incompetence, defined by a HR/VO2-ration, 2 beats/ml/kg, during DDDR pacing, compared to DDD, maximum heart rate increased from 83 +/- 13 to 132 +/- 7 beats/min (p < 0.01), maximum oxygen uptake from 12.7 +/- 3.1 to 15.3 +/- 3.2 ml/kg/min ( p < 0.05) and the VO2/WR-ratio from 8.1 +/- 1.0 to 9.0 +/- 0.9 ml/min/watts (p < 0.05). Exercise duration lengthened from 252 +/- 59 to 301 +/- 96 s (p < 0.05). During the 24-h Holter recordings the average maximum heart rate rose form 69 +/- 7 in the DDD mode to 78 +/- 9 beats/min in the DDDR mode significantly (p < 0.05). DDDR pacing did not result in an increased number of atrial salvos (2.6 atrial events/24 h) when compared to DDD pacing (2.5 atrial events/24 h, N.S.). These objective results were confirmed by the quality-of life assessment due to a symptom questionnaire. The symptom score declined from 20 +/- 10 in the DDD mode to 16 +/- 7 in the DDDR mode (p < 0.01). In the patients with chronotropic competence, however, cardiopulmonary exercise capacity did not improve in the DDDR mode: maximum heart rate was 120 +/- 21 versus 130 +/- 24 beats/min (N.S.), maximum oxygen uptake 17.7 +/- 5.9 versus 16.8 +/- 5.9 ml/kg/min (N.S.), The VO2/WR-ratio 9.8 +/- 2.3 versus 9.2 +/- 2.5 ml/min/watts (N.S.) and the exercise duration 407 +/- 159 versus 406 +/- 165 s (N.S.). The average maximum heart rate was 80 +/- 15 in the DDD mode and 83 +/- 16 beats/min in the DDDR mode (N.S.). Significantly more atrial arrhythmias occurred in the DDDR pacing mode: 1.6 atrial salvos per 24 h in the DDD mode versus 4.8 atrial salvos per 24 h in the DDDR mode (p < 0.05). This patient subgroup experienced a significant worsening of his quality-of-life. The symptom score rose from 20 +/- 9 in the DDD mode to 28 +/- 11 in the DDDR mode (p < 0.05). In conclusion, DDDR pacing improved cardiopulmonary exercise capacity, normalized heart rate variation over 24 h and increased quality-of-life in patients with chronotropic incompetence. On the contrary, since the DDDR pacing more could not improve cardiopulmonary exercise capacity, increased atrial arrhythmias and worsened the patient's quality-of-life, patients with chronotropic competence should not be programmed in the DDDR pacing mode.

[Solitary fibrous tumor of the epicardium]

A giant Solitary Fibrous Tumor (SFT) arising in the pericardium is described. A 53 year old woman was suspected to have a lung tumor and thoracotomy was performed. Intraoperatively the child-head sized mass was found to be localized in the pericardial sac. The histopathological interpretation of a small wedge-biopsy was 'endothelioma of uncertain malignancy' and heart-transplantation was performed two months later. The patient died of postoperative infection. Post mortem examination could exclude tumor rest or metastasis. The explanted heart revealed a large bulk of 2800 grams arising from the epicardium of the left chamber and enveloping the heart without invading the underlying myocardium. The histopathological pattern varied between cell-rich and -poor fibromatous areas and well capillarized endothelioma-like zones. Immunohistochemistry revealed positive reactions with monoclonal antibodies against Vimentin and CD 34 and no reactions against Cytokeratins and Faktor VIII. This pattern was confirmed in 7 SFT's of the pleura from our archives. A second control group of 7 mesotheliomas was positive for cytokeratins and vimentin but not for CD 34 and Faktor VIII. Diagnosis of SFT might be difficult because of its variability in histopathology, sometimes mimicking a hemangiopericytoma or endothelioma. Recent reports of tumor localizations devoiding serosal surfaces illustrate the diagnostic and histogenetic dilemma of this tumor. The differentiation of SFT from mesothelioma and endothelioma can be achieved by immunophenotyping including CD 34.

Etodolac selectively inhibits human prostaglandin G/H synthase 2 (PGHS-2) versus human PGHS-1

The isozymes of prostaglandin G/H synthase (PGHS) are shown to be differentially inhibited in vitro by currently marketed nonsteroidal anti-inflammatory drugs (NSAIDs) using microsomal rhPGHS-1 and rhPGHS-2. Comparison of selectivity ratios (IC50 rhPGHS-1/IC50 rhPGHS-2) demonstrated a 10-fold selectivity of etodolac (Lodine) for rhPGHS-2, whereas the other NSAIDs evaluated demonstrated no preference or a slight preference for inhibition of rhPGHS-1. In vitro enzyme results were supported by a human whole blood assay where etodolac also demonstrated a 10-fold selectivity for inhibition of PGHS-2 mediated TxB2 production. Taken together, these data may be key to explaining the clinically observed gastrointestinal safety of etodolac versus other marketed NSAIDs.

[Histopathology of Ph1-negative chronic myeloproliferative diseases]

The Ph1-negative groups of chronic myeloproliferative diseases (CMPD) are described, and histopathological criteria that distinguish them from each other are given. These are based upon observations in primary biopsies from 2,331 patients with CMPDs among a total of 34,160 patients referred between 1 January 1989 and 30 June 1994 to the Bone Marrow Registry. These cases of CMPD break down into the main groups as follows: CML 23.2%, megakaryocytic myelosis consistent with agnogenic myeloid metaplasia 22.3%, essential thrombocythemia 22.1%, and polycythemia vera 20.4%; 12.0% of cases were unclassifiable. Histological progress in each group is characterized by (1) increasing number and pleomorphy of megakaryocytes, (2) increasing fibrosis, and (3) excess of blasts. These three features can be observed in diagnostic biopsies before any therapy. Therefore, it is recommended that such alterations be reported semiquantitatively. A staging system with four stages from 0 to 3 for each of the three features is introduced. Its application allows staging for the individual patient on the basis of diagnostic biopsies.

Structure-activity relationships leading to WAY-121,520, a tris aryl-type, indomethacin-based, phospholipase A2 (PLA2)/leukotriene biosynthesis inhibitor

We were intrigued by reports of the inhibition of phospholipase A2 (PLA2) by indomethacin. In order to increase the potency of the indomethacin system as an inhibitor of PLA2, it was decided to make more lipophilic analogs. Indeed, covalent attachment of a quinoline ring to the methoxy substituent of indomethacin affords WAY-122,220 which is almost an order of magnitude more potent than indomethacin in inhibiting human synovial fluid PLA2 (IC50 = 15 and 145 microM, respectively). The N-p-chloro-benzyl analog of this compound, WAY-121,520, was an even more potent inhibitor of PLA2 (IC50 = 4 microM). Structural analyses and molecular modeling suggest that these compounds may inhibit PLA2 by mimicking arachidonic acid. WAY-121,520 is also a potent leukotriene biosynthesis inhibitor both in the rat PMN and mouse macrophage assays (IC50 = 10 and 4 nM, respectively), possibly acting via a 5-LO (5-lipoxygenase) translocation inhibition mechanism. The multiple actions of WAY-121,520 may contribute to its favorable anti-inflammatory profile.

Ultrastructural observations in hamster and rat lungs after chronic inhalation of cadmium compounds

Long-term inhalation of CdCl2 at concentrations as low as 12.6 micrograms Cd/m3 causes development of lung tumors in rats (4). No information, however, was available on the chronic carcinogenicity of CdO, CdS and CdSO4 which are especially relevant to the occupational area. In the present joint study of the Fh-ITA and the Fh-IUCT, rats and hamsters were exposed to CdCl2, CdSO4, CdO and CdS in a chronic inhalation carcinogenicity set-up (2, 3). The goal of the ultrastructural investigation was to compare inflammatory reactions and fibrotic lesions, as well as epithelial alterations occurring in the species under study. The present communication focusses especially on observations obtained from male and female hamsters and rats chronically exposed to CdO. In addition, we report preliminary results from a short-term inhalation study with CdO.