[Our experience with detection of JAK2 mutations in paraffin-embedded trephine bone marrow biopsies of patients with chronic myeloproliferative disorders]

Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) characterized by JAK2 mutation. The exon 14 V617F mutation is present in almost all patients with PV and in approx. 60% of patients with ET and PMF. The importance of JAK2V617F in the differential diagnostic considerations is still unclear and here the BM morphology examination still represents an important diagnostic tool. In the WHO classification of Ph1-negative MPNs, the identification of JAK2 mutations represents a major diagnostic criterion of these diseases. Therefore we decided to implement the examination of JAK2V617F mutation in formalin-fixed paraffin-embedded biopsy specimens of patients with Ph1-negative MPN using allele-specific PCR. In addition, in all JAK2 V617F negative patients with PV we sequenced the whole JAK2 exon 12. Until now we examined up to 200 patients with clinically confirmed MPN and our results in all three categories PV, ET and PMF are in agreement with earlier published data. Paraffin embedded tissues represent a valuable source of DNA which can be used in the diagnostics of both JAK2 exon 12 and exon 14 mutations. It is of particular importance if the fresh material is not available and there is a clinical and/or research utility for the performance of PCR on archival bone marrow samples with PV, ET or PMF suspicion.

[Laparoscopic distal pancreatectomy for neuroendocrine pancreatic tumors--initial experience]

INTRODUCTION

Although the first successful laparoscopic distal pancreatectomy in Martin was recorded in 2005, after five years we have successfully established this unique surgical procedure. The aim of this paper is to present two successful laparoscopic distal pancreatectomies in patients with neuroendocrine tumors of the distal pancreas.

MATERIALS AND METHODS

Laparoscopic distal pancreatic resection is currently challenging many pancreatobiliary surgeons. Its open alternative is the standard surgery for tumors in the body and tail of pancreas. Laparoscopic distal pancreatectomy meets all aspects of radical oncological resection including lymphadenectomy. Similarly to open resection is often associated with splenectomy, but brings significant benefit to the patient in the form miniinvasivity. The paper gives crucial points of surgical procedure that is still an unique surgery.

RESULTS

Although the last 4 months we operated on laparoscopically only 2 patients we present at least the preliminary experience with this method as well as a rich documentation of these procedures.

CONCLUSION

Laparoscopic distal pancreatectomy in the hands of an experienced laparoscopic surgeon has the chance to become an alternative to an open surgery.

[Commentary on development of the prognostic factors concept in chronic lymphocytic leukaemia: the route from prognostic factors to therapy response predictors]

Chronic lymphocytic leukaemia (CLL) is a lymphoproliferative disorder with variable clinical course. Determination of disease prognosis is based on the identification of different prognostic factors. The concept of CLL prognostic factors is still developing and has undergone several fundamental changes. Traditional (old) prognostic factors and staging systems are useful in describing the extent of the disease at any given moment, in determining clinical progression and in the identification of patients who need to start treatment. However, traditional prognostic factors are not sufficient for predicting a long-term prognosis because they are not able to identify potentially aggressive forms of CLL in the early stages. Nevertheless, clinical staging systems maintain their importance and in contrast to other traditional factors also their independent prognostic role. Otherwise, traditional prognostic factors play the role of disease activity descriptors rather than the role of actual prognostic factors. CLL risk profile determination is based on the identification of so-called new prognostic factors, the most relevant of which are chromosomal aberrations, TP53 gene mutations, mutational status of IgVH genes, ZAP-70 and CD38 expression. These factors are able to predict the prognosis already at the time of the initial diagnosis. In contrast to previous ideas, they are not incorporated into recommendations regarding indications for treatment. This is due to the risks associated with early treatment and the lack of data validated in prospective clinical trials demonstrating the justifiability of such procedure. In patients being treated, new prognostic factors may be useful for predicting the response to the therapy and some of them may directly influence the choice of treatment regime. New CLL treatment modalities have also raised the question of their influence on the prognostic and predictive power of new prognostic factors.

Fibrosis identified in the bone marrow biopsies of patients with essential thrombocythemia: its incidence and significance for the differential diagnostic considerations

Myelofibrosis (MF) may develop in all types of myeloproliferative disorders and its identification is of clinical relevance. Typical bone marrow (BM) morphology of patients with essential thrombocythemia (ET) shows either "normal" amount or "a slight increase" of reticulin fibers, but the published data differ in relation to the applied MF definition and ET diagnostic criterias. The aim of this study was to evaluate retrospectivelly MF in BM biopsies of 30 cases in which the diagnosis of ET was confirmed also clinically by local hematologists. In 7 of the patients not only primary but also sequential biopsy was available. The MF grade and extent were evaluated semiquantitativelly in archival slides stained by Gömöri silver impregnation. The analysis was based on the European clinicopathological criteria 2004 (ECP) defining a) normal bone marrow fibrosis (MF0), b) slight reticulin fibrosis (MF1), c) advanced reticulin and initial collagen fibrosis (MF2) and d) advanced collagen fibrosis (MF3). Generally, in majority of the biopsies MF0 (n = 6) or MF1 (n = 25, 18x focal and 7x diffuse) was found. More advanced MF2 was much less common as it was present in 6 biopsies (5x focal and 1x diffuse). In relation to the actual time of BM biopsy during course of the disease, the introductory biopsies done at the time of diagnosis (n = 18) showed 3x MF0, 14x MF1 and 1x MF2. The biopsies performed after a long time of patients observations (n = 12) showed 3x MF0, 7x MF1 and 2x MF2. In 5 of 7 sequential biopsies the progress of MF was evident, but 4 of these patients were treated by cytoreductive therapy. We conclude that the BM of patients with ET in initial phase shows either MF0 or focal slight increase of reticulin fibers (MF1). In addition, the long course of the disease and/or applied therapy may lead to more developed MF and more advanced MF stages (diffuse MF1 or MF2). Therefore their finding in the BM biopsies examined in the later phases of the disease should not exclude the diagnosis of ET.

Primary B-cell pituitary lymphoma of the Burkitt type: case report of the rare clinic entity with typical clinical presentation

Primary CNS lymphomas (PCNSLs) constitute 3% of all intracranial neoplasms. From these, primary pituitary lymphomas (PPLs) represent extremely rare clinical entity. Nearly all of PCNSLs are non-Hodgkin diffuse large B-cell lymphomas. We present a 60-year-old female with right-sided third cranial nerve palsy, mild bitemporal visual field deficit, severe cephalea, and polyuria-polydipsia. Hypopituitarism with hyperprolactinemia was confirmed; brain imaging revealed a 16 mm-diameter sellar mass with suprasellar extension. A presumptive diagnosis of pituitary adenoma was established. The patient underwent a neurosurgical intervention. Histopathological examination and immunophenotyping (cytokeratin, CD45+, CD79+, bcl-2-) verified high-grade B-cell non-Hodgkin lymphoma of the Burkitt type. Systemic work-up showed no other foci of lymphoma, the patient's HIV status was negative, Epstein-Barr virus status was not disclosed. Although PPL can be undistinguishable from pituitary adenoma at imaging, one should consider lymphoma when evaluating an invasive sellar mass that is iso- to hypointense on T2-weighted magnetic resonance images, particularly when the patient is immunocompromised or old and presents with diabetes insipidus, cranial nerve palsy and fever of unknown origin in addition to the expected finding of hypopituitarism.

Epithelioid haemangiosarcoma of the thyroid gland. Report of six cases from a non-Alpine region

AIM

To report a series of six cases of thyroid haemangiosarcoma (HAS) from a non-Alpine region.

METHODS AND RESULTS

The patients were four females and two males, aged 54-81 years (average 68 years). The tumours presented as large haemorrhagic masses (diameter 40-70 mm, average 56 mm) with extensive necrosis. Histologically, they were composed of polymorphous epithelioid cells with vesicular nuclei and abundant eosinophilic cytoplasm with occasional intracytoplasmic lumina. Mitotic activity was high. Tumor cells expressed vimentin (6/6), CD31 (6/6), FVIII (5/6), CD34 (2/6), and cytokeratins (5/6). One tumour (1/6) over-expressed p53 protein in more than 20% of cells. Ultrastructurally, Weibel-Palade bodies were present (4/6). Clinical follow-up of four patients (range 3-24 months, median 9 months) showed that two of them have died of the disease 0.5 and 3 months after diagnosis, one died of unrelated causes (with 24 months' uneventful follow-up) and one is alive 21 months after operation with no evidence of disease.

CONCLUSIONS

Although thyroid HAS is usually regarded as an extremely aggressive neoplasm with a dismal prognosis similar to anaplastic carcinoma, one of our cases suggests that HAS can behave in a less aggressive way. The morphological, immunohistochemical and ultrastructural findings support the hypothesis that thyroid HAS is a distinct entity, unrelated to other thyroid malignancies.

Effects of hyperoxia and allergic airway inflammation on cough reflex intensity in guinea pigs

Toxic influence of high oxygen concentration on pulmonary function and structures has been known for many years. However, the influence of high oxygen concentration breathing on defensive respiratory reflexes is still not clear. In our previous experiments, we found an inhibitory effect of 100 % oxygen breathing on cough reflex intensity in healthy guinea pigs. The present study was designed to detect the effects of hyperoxia on cough reflex in guinea pigs with allergic airway inflammation. In the first phase of our experiment, the animals were sensitized with ovalbumin. Thirty-two sensitized animals were used in two separate experiments according to oxygen concentration breathing: 100 % or 50 % oxygen for 60 h continuously. In each experiment, one group of animals was exposed to hyperoxia, another to ambient air. The cough reflex was induced both by aerosol of citric acid before sensitization, then in sensitized animals at 24 h and 60 h of exposition to oxygen/air in awake animals, and by mechanical stimulation of airway mucosa in anesthetized animals just after the end of the experiment. In contrast to 50 % oxygen, 100 % oxygen breathing leads to significant decrease in chemically induced cough in guinea pigs with allergic inflammation. No significant changes were present in cough induced by mechanical stimulation of airways.

[Amplification and overexpression of HER-2/neu in parotid gland salivary duct carcinoma. Immunohistochemical study and fluorescence in situ hybridization]

Salivary duct carcinoma (SDC) is highly malignant salivary gland tumour with aggressive clinical behaviour, characterised by its histological resemblance to invasive ductal carcinoma of the breast. Amplification of gene HER-2/neu and overexpression of its gene product have been shown to have both prognostic and treatment implications in breast cancer. The reports concerning the expression of c-erbB2/HER-2/neu in salivary gland tumours are few and controversial. Thus, eleven cases of SDC were evaluated for HER-2/neu status using immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). To the best of our knowledge, this is the first molecular genetic analysis of SDCs using FISH. HER-2/neu overexpression, identified as strong membrane staining, was observed in all but one case of SDC in majority of neoplastic cells while only four tumours, of nine cases analysed, revealed HER-2/neu gene amplification by means of FISH analysis. SDCs were associated with poor clinical outcome, 6 patients (55%) died of disseminated carcinoma within 4 to 44 months after therapy. There was no difference in outcome of patients with IHC positive-nonamplified and IHC positive-amplified tumours.

Expression of HER-2/neu gene and protein in salivary duct carcinomas of parotid gland as revealed by fluorescence in-situ hybridization and immunohistochemistry

AIMS

Salivary duct carcinoma is a highly malignant salivary gland tumour with aggressive clinical behaviour, characterized by histological resemblance to invasive ductal carcinoma of the breast. Amplification of HER-2/neu oncogene and over-expression of its gene product have both prognostic and therapeutic implications in breast cancer. Recent report on salivary duct carcinomas for HER-2/neu using immunohistochemistry (IHC) has shown over-expression in most cases. However, correlation between IHC and molecular genetic analysis of HER-2/neu in salivary duct carcinoma has not yet been performed.

METHODS AND RESULTS

We have now evaluated 11 cases of salivary duct carcinomas for HER-2/neu status using IHC and fluorescent in-situ hybridization (FISH). To our knowledge, this is the first molecular genetic analysis of HER-2/neu in salivary duct carcinoma.

CONCLUSIONS

In immunohistochemistry, over-expression of HER-2/neu protein was identified as distinct membrane staining in most carcinoma cells in all our salivary duct carcinoma cases, while only four cases revealed an amplification of HER-2/neu gene by means of FISH analysis. Both amplified and non-amplified salivary duct carcinomas with strong immunohistochemical staining for HER-2/neu protein were associated with poor clinical outcome for the patients. Apparently, HER-2/neu protein over-expression could also be controlled by mechanisms other than gene amplification. In the group of salivary gland tumours other than salivary duct carcinoma, strong over-expression was detected only in three cases of carcinoma ex pleomorphic adenoma. Thus, over-expression of HER-2/neu protein is also a useful marker of malignant transformation in pleomorphic adenomas.

[Primary mediastinal (thymus) large B-cell lymphoma: clinically defined type of tumors and morphologic variants]

In the WHO lymphoma classification, primary mediastinal (thymic) large B-cell lymphoma (PMVBL) is defined as a subtype of diffuse large B-cell lymphoma (DLBCL) showing typical clinical manifestation. The patterns related to variability of tumor cell morphology were analyzed in the setting of 15 bioptically verified PMVBL cases. In the majority of the cases (n = 12), the tumor showed pleomorphic blastic morphology with individual cell patterns resembling those of polymorphic centroblastoma of the Kiel classification. In addition, some of the cases had clear-cell and/or lacunar appearance (5/12), while distinctive anaplastic appearance was rare (1/12). Other cases (n = 3) showed a monotonous morphology of uniform smaller-sized blasts with monocytoid-like cytoplasm. The described morphologic variants of PMVBL might be related to the known genotypic variability of DLBCL, although monotypic c-Ig expression verified in some of the cases would support post-follicular stage of the tumor cell development. In the absence of clinical data and within the described morphologic variability, it is recommended to prefer a diagnosis of DLBCL and to include the tumor into a clinically defined subtype of PMVBL only in cases with well defined and typical clinical presentation and progression of the disease.

[Richter's syndrome (bimorphologic malignant lymphoma)]

Two distinct morphological types of malignant lymphoma in the same patient occur mostly due to transformation of a low grade lymphoma (CLL) into a large--cell non-Hodgkin lymphoma (high-grade lymphoma). Later reports have brough evidence of a clonal relationship between CLL and supervening NHL. The Richter's syndrome was found to be more frequent in patients with CLL displaying either multiple chromosomal aberrations or monoclonal gammapaties. In the last two decades reports have evidenced the existence of two types of the Richter's syndrome: one, the "classical" as a terminal event in a long evolving CLL, the other "variant" as the first clinical manifestation of a previously unrecognized subclinical CLL. Aggressive chemotherapy of CLL play a role in transformation of CLL to Richter's syndrome.

Salivary duct carcinoma--a highly aggressive salivary gland tumor with HER-2/neu oncoprotein overexpression

Salivary duct carcinoma (SDC) is a highly malignant salivary gland tumor with aggressive clinical behavior, and is characterized by its histological resemblance to invasive ductal carcinoma of the breast. Overexpression and/or amplification of proto-oncogene Her2/neu has been shown to influence both prognosis and treatment of breast cancer. Since salivary duct carcinoma and ductal breast carcinoma share many common characteristics, HER2/neu overexpression might also be important in SDC. However, data on the expression of c-erbB2/HER2/neu in salivary gland tumors are still scarce. Therefore, we have evaluated 15 cases of salivary duct carcinomas (SDC) for HER2/neu overexpression using immunohistochemistry with the HercepTest. Overexpression, identified as strong or moderate membrane immunostaining, was observed in all but one case of SDC in most neoplastic cells. Thus, our study suggests that anti-HER2/neu therapy with Herceptin is beneficial for patients with aggressive salivary duct carcinoma.

[Maffucci's syndrome--case report of a 5-year-old female patient]

Maffucci's syndrome is a congenital non-hereditary syndrome characterized by a combination of dyschondroplasia (enchondromatosis) and haemangiomatosis. It is a rare disease. During the last 140 years only 200 cases were described [5]. 109 cases are described in the literature by other authors [21]. This disease is associated with a high risk of development of neoplastic processes, in particular sarcomatous transformation of enchondromatoses as well as other mesodermal and non-mesodermal malignities [13]. Based on the incidence of spinocellular haemangioendothelioma with other congenital syndromes, the presence at a young age of patients and the multicentric incidence support the assumption that spinocellular haemangioendothelioma may be the manifestation of genetically based mesodermal disease which may be associated with the picture of Maffucci's syndrome [6]. In their case-history the authors present a 5-year-old patient. They describe the clinical course and findings taking into account possible manifestations and risks associated with the disease. With regard to the low incidence of the disease and its interdisciplinary character the authors pen the question of possible causal, symptomatic or palliative treatment.

[Intestinal T-cell lymphoma]

In our study, 7 bioptical specimens of intestinal T-cell lymphoma are described. This tumour occurs in the small intestine of adults who may have a history of malabsorption. The patients present clinically with intestinal perforation, enterorrhagia, or ileus. The gross appearance varies: the tumour may take the form of multiple ulcers or of a huge exulcerated lesion. The cytomorphological features are variable. Bizarre multinucleated cells may be sometimes present. The reactive cellular background is usually dominated by histiocytes or eosinophilic granulocytes. Immunohistochemically, the tumour cells stain in reactions with antibodies to pan T-cell markers, occasionally to CD8 and CD30. The positivity of tumour cells for markers of intraepithelial T-cells and for cytotoxic molecules has been demonstrated previously.

[Primary hepatosplenic T-cell (gamma delta) lymphoma: morphology and immunohistochemistry in 3 cases]

We analyzed one autopsy case and two biopsy cases of primary (hepato-)splenic lymphoma, diagnosed in numerous trephine bone marrow, spleen and liver biopsies. It is a distinctive "new" type of a rare T-cell lymphoma characterized usually by rearrangement of gamma delta chains of T-cell receptor. Morphologically, the lymphoma is composed of a cytologically monotonous proliferation of small to medium sized lymphocytes, with diagnostically characteristic intrasinusoidal spread in the bone marrow, spleen and liver. The involvement of the lymph nodes is always absent. Immunohistochemically, the tumor cells expressed constant CD3 positivity and negativity for B- and myelomonocytic antigens, together with an inconstant coexpression of CD43 and CD45RO. In contrast to other and more common primary B-cell splenic lymphomas, its biological behaviour is more aggressive.

[Occurrence of myelofibrosis in individual types of chronic myeloproliferative diseases]

BACKGROUND

During the course of chronic myeloproliferative disorders (CMPD), myelofibrosis (MF) represents a negative prognostic factor. The data concerning the incidence and progression of MF are rather heterogenous.

OBJECTIVES

The aim of the study was to evaluate the incidence and progression of MF in cases of CMPD registered in the Consultation Center for Haematopathology Biopsies in Martin Faculty Hospital.

METHODS

Fibrotic changes involving bone marrow were evaluated histologically semiquantitatively using reticulin fiber impregnation (method of Gomori). The study included 77 cases of chronic myelocytic leukemia (CML), 99 cases of polycythaemia vera (PV), 38 cases of essential thrombocythaemia (ET), and 126 cases of the fourth type of CMPD, mostly known as myelofibrosis/osteomyelofibrosis type (MF/OMF). The occurrence and degree of MF were evaluated at the time of all primary biopsies; in 52 of cases also in rebiopsy material.

RESULTS

At the time of primary diagnosis, MF occurred in 37/77 (48%) cases of CML, in 27/99 (27.3%) cases of PV, in 8/38 (21%) cases of ET, and in 119/126 (94.4%) cases of MF/OMF. In repeated (secondary) biopsies, the progression of MF or evolution to MF was most common in CML and MF/OMF types.

CONCLUSIONS

At the time of the CMPD diagnosis, more than 50% of cases showed the presence of MF. During the course of CMPD, the MF seems to represent a dynamic process evolving the underlying disease. The early diagnosis of MF is important for the selection of the appropriate therapeutic regimen. (Tab. 3, Fig. 2, Ref. 23.)

[Mantle cell lymphoma (MCL)--histopathology and clinical features]

Mantle cell lymphoma (MCL) has been established as a clinicopathologic entity in 1991. A histopathologic and immunohistochemical study of 16 cases of MCL was performed in order to demonstrate differential diagnostic aspects. MCLs were composed of small and medium-sized B cells assuming the appearance of centrocytes. The growth pattern was diffuse in 9 cases and that of follicle mantle zone type within at least partially present nodular parts in 16 cases. The immunohistochemical staining for CD23 antigen was negative in tumour cells whereas the strong immunoreactivity of follicular dendritic cells (FDC) decorated residual FDC network. Seven cases of MCL were examined for the presence of translocation t(11;14)(q13;q32) using polymerase chain reaction. Despite histomorphological features compatible with a diagnosis of low-grade lymphoma, MCL has a worse prognosis and more aggressive behaviour than other types of small cell lymphomas, such as small lymphocytic lymphoma and follicle centre lymphoma.

[Monoclonal plasmacytic differentiation in small-cell lymphomas of B-cell origin: immunocytoma versus other types]

We have studied the morphological and immunohistochemical features of monoclonal cytoplasmic Ig (c-Ig) production in the biopsy material of 161 small B-cell non-Hodgkin's lymphomas to verify a frequency of the plasmacytic/plasmacytoid differentiation of tumor cells for the aims of their differential diagnosis. The analyzed differentiation was identified in all the cases of immunocytoma (n = 20/20), in 2/3 of MALT-lymphomas (n = 24/38) and 1/2 of monocytoid B-cell lymphoma cases (n = 4/7), in 1/5 of centroblastic-centrocytic lymphoma cases (n = 12/60) and rarely in centrocytoma (n = 4/36). We conclude that a plasmacytic differentiation is not an unique feature of the immunocytoma. For the differential diagnosis, a histological analysis and not a proof of monoclonal c-Ig itself seems to be decisive. The obtained results are discussed in relation to the histogenesis of small B-cell lymphomas, which represent a neoplastic counterpart of the reactive B-cells at different stages of their maturation and differentiation.

[Treatment of MALT lymphoma of the digestive tract]

Mucosa-associated lymphoid tissue (MALT) is an autonomous part of the immune system with a specific function, histological structure and circulation of cells. As a result of malignant transformation of this tissue maltomas develop, peripheral extranodal non-Hodgkin lymphomas of B-origin more than two-thirds of which are found in the digestive system. The authors investigated in a retrospective study the effectiveness of different types of treatment of maltomas of the digestive tract with a low and high grade of malignity in 16 patients. It appears that splenectomy is not necessary in these patients and that the effectiveness of primary chemotherapy with a view of inducing complete remission of the disease is comparable with surgical treatment and subsequent adjuvant treatment without deterioration of the patient s life by mutilating surgery. An integral part of treatment of gastric maltomas is eradication of infection caused by Helicobacter pylori.

[Histocytopathology of monocytoid B-lymphocytic lymphoma]

It is generally accepted, that the cells of non-Hodgkin's lymphomas represent a neoplastic counterpart of corresponding reactive cells. The aim of this study was to compare histocytology of 6 cases of monocytoid B-cell lymphoma (MBCL) with that of reactive monocytoid B-cells of "common" and large cell type. All the lymphomas were diagnosed in peripheral lymph nodes by histology and immunohistochemistry. Histocytological appearance of MBCL corresponded mostly to that of "common typ" MBLy (n=5) with. signs of plasmacytic differentiation (p = 3/5) or rarely (n=1) with increase of intermingled blast cells. Rebiopsy of one of the cases of the "common" cell type showed a progression to a large cell high grade lymphoma of the appearance similar to the large cell type of reactive MBCs. It is therefore to be accepted that the cells of MBCL including its high grade transformation might represent neoplastic counterparts of the reactive MBLy of the "common" and large cell type respectively.

[Functional and morphological changes in the respiratory organs of cats after long-term exposure to pure normobaric oxygen]

BACKGROUND

Pulmonary oxygen toxicity is very well known and proved. The influence of hyperoxia on the respiratory reflexes is not known till now.

MAIN PURPOSE

To ascertain if long-lasting breathing of pure normobaric oxygen (PNO) alter respiratory reflexes.

METHODS

34 adult cats of both sexes, weighing 2.5-4.0 kg, were used in two experiments. In the first experiment 16 animals with inserted chronic tracheal cannula (CTC) were used. In the second experiment 18 animals without CTC were employed. Part of animals in both experiments was exposed to PNO (day by day for 2 weeks, 10 h daily), remaining animals were exposed to room air under the same conditions. Side tracheal pressure was recorded in unanesthetized animals of the first experiment. The second experiment was performed in anaesthetised animals (Pentobarbital Spofa, 35 mg/kg, i.p.). Oesophageal pressure and blood pressure in femoral artery were recorded. Cough reflex, sneezing and aspiration reflexes were induced by mechanical stimulation of airway mucosa. Pulmonary chemoreflex was elicited by i.v. administration of 50 micrograms phenyl biguanid. Hering-Breuer inflation reflex was induced by lung inflation with pressure of 1 kPa. Reactivity of tracheal and pulmonary smooth muscle to histamine were measured in vitro. Differences in recorded parameters between animals exposed to PNO, and to room air, were tested by Mann-Whitney-Wilcoxon test and by Student's t-test. When p < 0.05, the differences were recognized as significant.

RESULTS

Significant decreasing of the expiratory parameters of the cough induced from laryngopharyngeal mucosa, inhibition of sneezing, and inhibition of aspiration reflex, were found in animals exposed to PNO. Relaxing reaction of tracheal smooth muscle of control animals to histamine was reversed to contraction in animals exposed to PNO. Morphological changes of the respiratory tract induced by influence of oxygen were found

CONCLUSION

Long-lasting breathing of PNO induced changes of respiratory reactions elicited mainly from upper airway.(Fig. 6, Tab. 3, Ref. 22)

[Monocytoid B-lymphocyte lymphoma: a new type within the spectrum of non-Hodgkin's B-cell lymphoma]

BACKGROUND

Clonal proliferation of monocytoid B-lymphocytes (MBLy)--monocytoid B-cell lymphoma (MBCL) represents a "new" type of lymphoma within the spectrum of B-cell malignancies.

OBJECTIVES

The aim of the study was to evaluate the possibilities of a routine histological and immunohistochemical diagnosis of MBCL.

METHODS

Three cases of MBCL diagnosed in peripheral lymph nodes (n = 2) and in mammary gland with infiltration of regional lymph node (n = 1) were analyzed both histologically and immunohistochemically using a panel approach (Ig chains, CD30 antigen, markers of B-cells, T-cells and of monocytes/histiocytes).

RESULTS

Morphological appearance of neoplastic cells of MBCL is identical to that of MBLy in reactive conditions--kidney-shaped nuclei, bright clear PAS-negative cytoplasm, and small inconspicuous nucleoli.

CONCLUSIONS

Morphological appearance together with immunophenotypic results (positivity of CD20 and Ki-B5, negativity of CD3, CD43, CD45RO, and of lysozyme, negativity of CD30) are considered to represent sufficient diagnostic criteria of MBCL, including its differential diagnosis of other B-cell low grade malignancies. An increase of large cell type MBLy might represent a feature of a secondary blastic transformation of MBCL. (Tab. 2, Fig. 5, Ref. 27.)

[Primary MALT-type malignant lymphomas of the salivary glands]

Six cases of primary extranodal lymphomas in big salivary glands, which met criteria of MALT lymphoma, were investigated with the aid of antibodies against Ig, light chains, LCA and EMA, in addition in two cases against Ig heavy chains and with antibodies KL-1 and VCHL-1. All the tumours had centrocytoid morphological features, one of them showed signs of focal blastic transformation into centrocytoid centroblastoma. Tumour cells showed twice plasmacytic and three times plasmacytoid differentiation with intracytoplasmic Ig monoclonality (once IgM/kappa, once IgA/kappa, three times kappa positivity). They were positive in reaction against epimyoepithelial proliferation. A picture of myoepithelial sialoadenitis with partial lymphomatous infiltration prevailed in two cases and a lymphoma picture with remnants of sialoadenitis in three cases. Features of inflammatory process were lacking in a case with blastic transformation. There is a dispute whether features of sialoadenitis belong to the defining criteria of MALT type lymphoma or can disappear during blastic transformation of a low grade malignant lymphoma.