Regenerative abilities of a nanofiber wound dressing based on polylactide.

INTRODUCTION: The development of an ideal dressing for wound healing remains an unresolved issue. Thanks to the development of electrospinning technology, polymers in the form of nanofibers have come to the forefront of research interest. A modern and very promising dressing material is a “nonwoven” based on nanofibers of the synthetic polymer polylactide (PLA). The aim of this work was to assess the regenerative abilities of PLA in a standardized wound in a porcine model and compare our results to the literature data. METHODS: We applied PLA-based nanofiber dressings to the standardized wounds created in the porcine model. On the third, tenth, seventeenth and twenty-fourth days after the formation of the defect, we changed the wound dressing while taking a tissue sample for histopathological examination. We continuously monitored serum levels of acute phase proteins. RESULTS: PLA stimulated an inflammatory response. From the third day, the thickness of the fibrin layer with granulocytes increased. It reached its maximum values on the tenth day (mean 340 μm); at the same time the level of serum amyloid A, as a marker of inflammation, culminated. The individual phases of healing intertwined. The highest thickness values of the granulation tissue with cellular connective tissue (diameter 8463 μm) were reached on the seventeenth day. On the twenty-fourth day, the defects were healed macroscopically with a mean reepithelialization layer of 9913 μm. CONCLUSION: PLA-based nanofiber dressing potentiates the inflammatory, proliferative and reepithelialization phases of healing. Its structure perfectly mimics the extracellular matrix and serves as a 3D network for the growth and interaction of cellular elements. In addition to biocompatibility, PLA has a unique ability of two-phase biodegradation. It is a promising material for industrial production of dressing materials. Most of the available studies were performed in vitro. In vivo comparative studies approximating the use of PLA to daily practice are still missing.

Expression of selected microRNAs in pancreatic ductal adenocarcinoma: is there a relation to tumor morphology, progression and patient's outcome?

Pancreatic ductal adenocarcinoma (PDAC) remains a disease with extremely poor prognosis and limited effective available treatment. Differential expression of miRNAs isolated from tumor tissue has been proposed as a marker for tumor diagnosis, progression, and prognosis. Nevertheless, the prognostic value of miRNAs expression in PDACs for patient outcome still remains unclear. Expression of 7 selected miRNAs, isolated from FFPE samples of 54 PDAC patients, was quantified using RT-qPCR. The relationship of miRNA expression levels with tumor histology, clinicopathological characteristics, patient overall survival (OS), and progress-free survival (PFS), was subsequently evaluated. Overexpression of miR-21, miR-155, and miR-210 was observed in PDACs (up to 72.62, 232.36, and 181.38-fold, respectively), in comparison with non-neoplastic tissues. On the other hand, miR-96 and miR-217 were significantly downregulated in PDACs (up to one hundred times). No differences were, however, noticed between cancer and normal tissues for the expression levels of miR-148a and miR-196a. On the other hand, expression levels of all 7 miRNAs failed to demonstrate a significant correlation with parameters of tumor progression, such as tumor stage, grade, nodal involvement, perineural, and vascular invasion. The positive correlation of miR-210 levels was, however, observed with patient age (ρ=0.35). Additionally, miR-148a and miR-217 expressions have shown a positive association with tubular tumor growth pattern (ρ=0.39; ρ=0.28). The negative correlation of miR-148a values was also demonstrated with dissociative growth pattern and nuclear atypia (ρ=-0.30; ρ=-0.27). Finally, no statistically significant correlation could be demonstrated with the expression levels of all 7 tested miRNAs and PDAC patient survival; neither for OS nor for PFS (p>0.05). Our data have confirmed abnormal miRNAs expression in PDACs in comparison with adjacent non-neoplastic tissue. On the other hand, no correlation was discovered between miRNA expression and parameters of tumor progression. We have found a significant association between histologic tumor growth patterns and miRNA expression, making this work the first study, which analyses this aspect of PDAC. Finally, in our group of patients, no relationship of miRNA levels and patient prognosis could be demonstrated. Therefore, further investigation is required to evaluate the predictive and prognostic potential of miRNAs in a clinical setting.

Valproic Acid Decreases the Nuclear Localization of MDT-28, the Nematode Orthologue of MED28.

Mediator is a multiprotein complex that connects regulation mediated by transcription factors with RNA polymerase II transcriptional machinery and integrates signals from the cell regulatory cascades with gene expression. One of the Mediator subunits, Mediator complex subunit 28 (MED28), has a dual nuclear and cytoplasmic localization and function. In the nucleus, MED28 functions as part of Mediator and in the cytoplasm, it interacts with cytoskeletal proteins and is part of the regulatory cascades including that of Grb2. MED28 thus has the potential to bring cytoplasmic regulatory interactions towards the centre of gene expression regulation. In this study, we identified MDT-28, the nematode orthologue of MED28, as a likely target of lysine acetylation using bioinformatic prediction of posttranslational modifications. Lysine acetylation was experimentally confirmed using anti-acetyl lysine antibody on immunoprecipitated GFP::MDT-28 expressed in synchronized C. elegans. Valproic acid (VPA), a known inhibitor of lysine deacetylases, enhanced the lysine acetylation of GFP::MDT-28. At the subcellular level, VPA decreased the nuclear localization of GFP::MDT-28 detected by fluorescencelifetime imaging microscopy (FLIM). This indicates that the nuclear pool of MDT-28 is regulated by a mechanism sensitive to VPA and provides an indirect support for a variable relative proportion of MED28 orthologues with other Mediator subunits.

[Synchronous colorectal carcinoma and non-Hodgkin lymphoma - two case reports]. / Synchronní kolorektální karcinom a nehodgkinský lymfom - popis dvou prípadu.

Colorectal carcinoma represents an important cause of morbidity and mortality in adults, and its incidence in the Czech Republic is one of the world´s highest. The basic therapeutic approach is surgery: surgical removal of the affected part of the bowel together with regional lymph nodes dissection. The lymph nodes are routinely examined by means of histopathology. In this paper, we present two patients whose histological examination of mesocolic lymph nodes revealed an infiltration by synchronous malignant B-non-Hodgkin-lymphoma. Mantle cell lymphoma was present in the first case, and small cell lymphoma CLL/SLL in the other. Relevant literature is reviewed. KEY WORDS: synchronous - malignancy - colorectal - lymphoma - lymph node.

Large contribution of human papillomavirus in vaginal neoplastic lesions: a worldwide study in 597 samples.

AIM: This work describes the human papillomavirus (HPV) prevalence and the HPV type distribution in a large series of vaginal intraepithelial neoplasia (VAIN) grades 2/3 and vaginal cancer worldwide. METHODS: We analysed 189 VAIN 2/3 and 408 invasive vaginal cancer cases collected from 31 countries from 1986 to 2011. After histopathological evaluation of sectioned formalin-fixed paraffin-embedded samples, HPV DNA detection and typing was performed using the SPF-10/DNA enzyme immunoassay (DEIA)/LiPA25 system (version 1). A subset of 146 vaginal cancers was tested for p16(INK4a) expression, a cellular surrogate marker for HPV transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance. RESULTS: HPV DNA was detected in 74% (95% confidence interval (CI): 70-78%) of invasive cancers and in 96% (95% CI: 92-98%) of VAIN 2/3. Among cancers, the highest detection rates were observed in warty-basaloid subtype of squamous cell carcinomas, and in younger ages. Concerning the type-specific distribution, HPV16 was the most frequently type detected in both precancerous and cancerous lesions (59%). p16(INK4a) overexpression was found in 87% of HPV DNA positive vaginal cancer cases. CONCLUSIONS: HPV was identified in a large proportion of invasive vaginal cancers and in almost all VAIN 2/3. HPV16 was the most common type detected. A large impact in the reduction of the burden of vaginal neoplastic lesions is expected among vaccinated cohorts.

[Gastroesophageal reflux disease. Standards of the Czech Society of Gastroenterology--actualization 2009]. / Refluxní choroba jícnu. Standardy Ceské gastroenterologické spolecnosti--aktualizace 2009.

Presently, gastroesophageal reflux disease is defined as a disorder where reflux of the stomach content is bothersome and/or brings about complications. The state when macroscopically detectable erosions of mucosa are present is known as erosive reflux disease and the term non-erosive reflux disease is used for the condition with no macroscopic erosions. Reflux oesophagitis is a frequent sign of the disease. A condition, where reflux symptoms persist or new occur and oesophagitis healing fails to take place despite maximum treatment, is classified as refractory gastroesophageal reflux disease. The main symptoms of gastroesophageal reflux disease include heartburn and regurgitation. Gastroesophageal reflux disease may, less frequently, manifest itself with isolated non-oesophageal symptoms, e.g. recurring upper respiratory tract infections or bronchial asthma. Etiopathogenesis involves refluxate, motility disorders, altered anatomic proportions, protective mechanisms disorder and external factors. Diagnosis takes place on the basis of typical symptomatology and endoscopic examination. Complications include bleeding, ulceration, strictures and Barrett's oesophagus. Lifestyle and dietary measures are an important treatment approach as are pharmacological (antisecretion and prokinetic agents) as well as surgical management.

[Neuroendocrine tumours of the alimentary tract--history and at present]. / Neuroendokrinní nádory trávicího ústrojí--historie a soucasnost.

Histological classification of the neuroendocrine tumours ("carcinoids") of the alimentary tract, as well as the opinion on biological behaviour of these tumours, changed rapidly within the last decade. Advances in knowledge of cellular biology of the diffuse endocrine system and in clinical diagnostics and treatment of tumours lead to the creation of a new histological classification of neuroendocrine tumours. This classification, apart from essential histological picture and immunohistological characterisation of the markers of neuroendocrine differentiation, also includes definition of biological properties of tumours based on their site of origin, mitotic and proliferative activity of the tumour cells and clinicopathological correlation, including the size of the tumour and its progression. Exact classification of an individual tumour into a corresponding category is an essential condition to select adequate following diagnostic procedures and optimal therapeutic strategy.

[Merkel cell carcinoma--immunohistochemical study in a group of 11 patients]. / Karcinom z Merkelových bunek--imunohistologická studie v souboru 11 pacientu.

The aim of our work was to confirm an immunohistochemical profile of routine markers of epithelial and neuroendocrine differentiation in eleven cases of Merkel cell carcinoma, as well as to study the expression of two markers of early phases of neuronal differentiation, namely reelin and class III beta-tubulin, markers which have not yet been studied in Merkel cell carcinomas. In all the investigated tumours the characteristic "dot-like" pattern of cytokeratin 20 immunoexpression, as well as negative immunostaining for cytokeratin 7 and thyroid transcription factor 1 (TTF-1) were disclosed; all the tumours showed neuroendocrine differentiation, expressing either neuron specific enolase (NSE) or chromogranin A(CgA), or both. An interesting finding was observed when the anti-cytokeratin monoclonal antibody MNF 116 was used. The characteristic "dot-like" pattern was detected in high proportion of tumours, including two samples of local recurrence of one of the carcinomas, where neoplastic cells have lost the expression of cytokeratin 20. The majority (91%) of Merkel cell carcinomas included in our group showed positive immunodetection of class III beta-tubulin when TU-20 antibody was used, while TuJ-1 immunostaining was surprisingly negative in all the investigated tumours. Detection of reelin was negative in almost all the studied Merkel cell carcinomas except for cases, where neoplastic cells revealed weak focal immunostaining in a minor portion of neoplastic cells.

Expression of class III beta-tubulin in colorectal carcinomas: an immunohistochemical study using TU-20 & TuJ-1 antibody.

BACKGROUND & OBJECTIVE: Expression of class III beta-tubulin represents newly discovered marker of resistance to taxol-based chemotherapy in a wide spectra of carcinomas. However, very little is known about its expression in colorectal carcinomas. This study was done to determine class III beta-tubulin expression in a large series of colonic carcinomas, covering tumours with different degree of differentiation in order to evaluate its prospective significance in resistance to taxol-based chemotherapeutics and to compare the immunostaining profile of two widely used monoclonal antibodies, TU-20 and TuJ-1 METHODS: Sixty patients with colorectal carcinoma were enrolled; all of them were treated surgically by the resection. Twenty tumours were histologically assessed as G1, 20 as G2 and 20 as G3. Routine immunohistochemical procedure using TU-20 and TuJ-1 mouse monoclonal antibodies was applied to all 60 specimen and slides were evaluated using an optical microscope. RESULTS: Expression of class III beta-tubulin was detected in 14 tumours (23.3%), while remaining tumours were negative. Relatively higher frequency of class III beta-tubulin expression was observed in G3 tumours (10 cases) in comparison with G1 (3 cases) and G2 (1 case), respectively. Seven tumours displayed positive immunostaining with both tested antibodies TU-20 and TuJ-1. Six tumours showed expression of class III beta- tubulin in more than 1 per cent of neoplastic cell population. In remaining 8 tumours only individual scattered neoplastic cells exhibited class III beta-tubulin expression either with TU-20, or with TuJ-1 antibody. INTERPRETATION & CONCLUSION: Higher frequency of immunoreactivity was observed in poorly differentiated tumours. However, more than 90 per cent of neoplastic cell population did not express class III beta-tubulin in almost all tumours. These negative cells of colonic cancer could represent the potential target for taxane-based chemotherapy in the future. Our results indicate that TU-20 and TuJ-1 antibodies exhibit very similar immunoreactivity in neoplastic tissue.

[Leiomyoma of the abdomen wall. Case report]. / Leiomyom piední steny birisní.

Authors present the case report of the patient indicated to plastic of abdomen wall for large hernia. Per operation, tumor was found without communication with abdomen cavity and organs. Histopathologically, leiomyoma of the abdomen wall was identified.

[Diagnostics of the retrocalcaneal bursitis: possibilities of the use of new anatomical data]. / Diagnostika retrokalkaneárních burzitíd: moznosti vyuzití nových anatomických poznatku.

The anatomy and histology of the normal retrocalcaneal bursa (RB) was studied on both embalmed and fresh cadaverous material. The bursa is a constant structure, its upper and posterior walls are completely covered with the unilayered synovial membrane. Its anterior wall represents the superior facet of the calcaneal tuberosity, the posterior one corresponds to the anterior surface of the insertional part of the Achilles tendon. The superior wall is formed by the adipose tissue of the inferior part of Kager's triangle, extending into the cavity of the bursa in a form of constant large and irregularly shaped synovial fold. The normal anatomical features as well as some pathological changes of the bursa and its neighbourhood were demonstrated on examples of some case reports, by use of the ultrasonography and magnetic resonance investigations. In healthy individuals the space of the bursa was not figured in the ultrasonographic investigations, but was well apparent in the MR images. The pathological changes of the bursa are detectable by using of both methods, but the MR images present substantially precise quality of depiction. The authors recommend the use of presented new anatomical data for the improvement in differential diagnostic of the wide spectrum of achillar enthesopathies.

Clinical anatomy of the retrocalcaneal bursa.

The goal of the study was to perform a detailed anatomical description of the retrocalcaneal bursa (RB). Its morphological arrangement was studied on 10 fresh and 30 embalmed lower extremities by microdissection and light microscopy. The RB was present constantly and in all the cases contained 1-2 cm long synovial fold, beginning on the upper wall of RB and distally interposed between the anterior surface of the Achilles tendon and the posterior surface of the calcaneal tuberosity. The volume of RB was 1-1.5 ml. The histological analysis confirmed that the inner surface of the superior and posterior wall of RB have been covered by unilayered synovial membrane, projecting into synovial villi of different shapes and sizes. In the ceiling of RB, delicate fascicle of skeletal muscle fibers was discovered, radiating distally into the regularly present synovial fold. The whole bottom of RB has been covered by 200-500 microm layer of fibrous cartilage into which the calcaneal tendon attached. The cartilagineous layer continued anteroproximally to cover the whole bursal surface of the calcaneal tuberosity, where the thickness of the cortical bone was reduced on mere 50 microm. The obtained results can be used in the improvement of the differential diagnostics and therapy of diagnostics and therapy of the retrocalcaneal bursitis as well as of other kinds of achillar enthesopathies and heel pain.

Markers of Chlamydia pneumoniae and human cytomegalovirus infection in patients with chronic peripheral vascular disease and their relation to inflammation, endothelial dysfunction and changes in lipid metabolism.

Our aim was to detect markers of Chlamydia pneumoniae (CPN) and human cytomegalovirus (HCMV) infection in patients with peripheral vascular occlusive disease and to follow markers of inflammation, endothelial dysfunction and lipid metabolism alteration in patients with active infection. CPN genome was detected in 9 (47.4 %) patients by at least one PCR method. Serological markers of acute CPN infection were found in 5 (26.3 %) subjects; each of them showed also positivity in at least one of the PCR methods. HCMV DNA were detected in 2 (10.5 %) patients; HCMV-specific antibodies were detected in 14 (73.7 %) subjects, however only in IgG subclass. Subjects with HCMV PCR positivity thus showed no serological markers of active HCMV infection. Laboratory findings of acute CPN infection were associated with increased plasma levels of Lp(a), triacylglycerols, atherogenic index of plasma and E-selectin (p < 0.05). No significant differences were found in the other markers, including plasma levels of total cholesterol, ferritin, homocysteine, oxidized LDL, IL-6, IL-8, IL-18, TNF-alpha, soluble forms of VCAM-1 and ICAM-1, von Willebrand factor, C-reactive protein, and plasma nitrites & nitrates. Frequent presence of chlamydial DNA in atheromatous plaques from patients with peripheral vascular disease was confirmed. HCMV DNA was detected only sporadically and with positivity in anamnestic anti-HCMV antibodies (IgG) only, indicating a rare presence of latent virus rather than active replication. Patients with laboratory markers of acute CPN infection exhibited more pronounced alterations in lipid metabolism and endothelial dysfunction.

Expansion of human mesothelial progenitor cells in a longterm three-dimensional organotypic culture of Processus vaginalis peritonei.

A 3D culture system was used to investigate the behaviour of mesothelial cells present in the wall of human processus vaginalis peritonei. Small tissue fragments placed on collagen sponges were cultured for 7, 14 and 21 days in medium supplemented with 10% FBS, and analysed for the expression and distribution of cytokeratins (CKAE1-AE3, CK19), p63, Ki-67, vimentin, CD34, and HBME-1. Before culture, flat mesothelial cells displayed immunoreactivity for cytokeratins, vimentin and HBME-1, while p63 and CD34 were negative. Mesenchymal cells within the stroma were vimentin-positive and endothelial cells of small vessels displayed positive staining for CD34. Cytokeratins, p63 and HBME-1 were negative in all stromal cells. In cultured fragments, flat mesothelial cells positive for vimentin, cytokeratins and HBME-1 proliferated, lining the fragment surface and migrating into the sponge. Capillaries showed morphological alterations; however, their immunoreactivity was comparable with the stroma prior to culture. Cells that had migrated into the sponge and displayed characteristics of mesothelial progenitors, predominantly spindleshaped and stellate, showed heterogeneous expression of markers especially in late phases of cultivation. These cells were constantly positive for vimentin, a small fraction was cytokeratin-positive and a few displayed HBME-1 immunoreactivity. CD34 was found in cells forming small cavities into the matrix, resembling newly formed blood vessels. Cells that had migrated into the sponge could be isolated and expanded in coculture with feeder NIH.3T3 fibroblasts. This system is suitable for studying growth and behaviour of mesothelial cells within their natural environment, providing a good method for isolation and expansion of their progenitor cells.

Human papillomavirus infection and tumours of the anal canal: correlation of histology, PCR detection in paraffin sections and serology.

Human papillomavirus infection is an important etiological factor in squamous cell carcinoma of the anus (SCCA). Different histological variants of anal carcinomas displaying squamous differentiation, previously classified as separate tumours, were recently reclassified as SCCA by the WHO. In our recent study the presence of HPV was detected by PCR in biopsy specimens of 42 different anal tumours, including SCCA and its histological variants (n=22), adenocarcinomas (n=5), tubulovillous adenomas (n=5) and anal condylomas (n=10). HR HPV16 (high risk - HR) was detected in 18 of SCCA specimens (81.8%). All histological variants, i.e. tumours with basaloid, squamous and mixed histological patterns, were represented among the HPV-positive cancers. Four tumours (18.2%) were HPV negative. Low-risk (LR) HPV types were not detected within the SCCA group. HPV16 was identified in one adenocarcinoma, while four cases were HPV negative. Two adenomas showed presence of HPV16; one showed simultaneous positivity for HPV33. The remaining three tumours were HPV negative. Seven anal condylomas (70%) were LR HPV 6 and/or 11 positive, while three were HPV negative. The presence of HR HPV types was not observed in anal condylomas. Our results provide further evidence in support of the etiological role of HR HPV infection in the development of SCCA regardless of its histological appearance.

Accuracy of angiography and Doppler ultrasonography in the detection of carotid stenosis: a histopathological study of 123 cases.

BACKGROUND: A prospective study was performed comparing the accuracy of digital subtraction angiography (DSA) and Doppler ultrasonography (DUS) stenosis findings with measurements on histological specimens. METHOD: DSA and DUS were used to evaluate carotid stenosis and were compared with measurements on histological specimens. Intact carotid plaques from 123 cases were removed in one piece during surgery. The specimens were histologically processed and examined in transverse sections. The smallest inner and correlating outer diameters were measured and the extent of stenosis was calculated. Carotid artery stenoses were compared and statistics done. Specimens in symptomatic cases were divided into 3 groups: stenosis 30-49% (Group 1), stenosis 50-69% (Group 2) and stenosis 70-99% (Group 3). Specimens in asymptomatic cases were divided into two groups: stenosisor=60% (Group B). FINDINGS: Wilcoxon paired tests revealed significant differences between DSA, DUS and measurements on histological specimens. In severe stenoses only, no significant difference was observed between stenosis measurement according to the European Carotid Surgery Trial (ECST) angiography methodology and measurements on histological specimens. The most pronounced differences were found between angiography methodology of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and measurements on histological specimens. When investigating how often preoperative measurement classified stenosis into the same Group of stenoses as postoperative measurement, DUS was the most accurate diagnostic tool. CONCLUSIONS: This study confirmed our previous results, i.e., angiography underestimates the degree of carotid artery stenosis. DUS seems to be more accurate in classifying stenoses into different groups to the extent of narrowing of the carotid arteries. These results make the position of angiography in diagnostic algorithm of carotid stenoses investigations even more questionable.

Expression of CD44v6 correlates with cell proliferation and cellular atypia in urothelial carcinoma cell lines 5637 and HT1197.

CD44 comprises a family of membrane adhesion molecules encoded by a single gene and diversified by alternative splicing and extensive posttranslational modifications. Alterations of CD44 expression patterns are linked to tumour invasion and formation of metastases. However, CD44 expression and its relation to the biological properties of tumours vary depending on the tumour type and origin. In transitional cell carcinoma of the urinary bladder, low CD44 expression is linked to enhanced tumour aggressiveness. We studied CD44 expression in two urothelial cancer cell lines, HT1197 and 5637. CD44s and a v6 variable exon-containing splice variants were detected in both cell lines by reverse transcription-PCR and by commercially available monoclonal antibodies. In both cell lines, Western blot analysis detected immunoreactive proteins with approximate sizes 70-85 kD, 95-110 kD, and 120-140 kD with CD44v6 antibody and weak bands with size 70-98 kD with CD44s antibody. At the cellular level, the pattern of CD44 immunoreactivity correlated with a lower level of cell differentiation and a higher degree of cell proliferation. In HT1197 cells, the CD44v6 was detected predominantly in small proliferating cells and in large multinuclear atypical cells. CD44s and CD44v6 displayed low immunoreactivity in HT1197 cells with a higher degree of epithelial differentiation. The 5637 cells expressed CD44v6 strongly and CD44s weakly. We conclude that CD44v6 expression correlates with a higher proliferative activity and with a stem cell-like phenotype in both cell lines and with cellular atypia in HT1197 cells.

Chromophobe renal cell carcinoma with microcystic and adenomatous arrangement and pigmentation--a diagnostic pitfall. Morphological, immunohistochemical, ultrastructural and molecular genetic report of 20 cases.

We present clinical, morphological, immunohistochemical, ultrastructural and molecular genetic features of 20 cases of a peculiar form of chromophobe renal cell carcinoma (CRCC) with morphology differing from that of conventional CRCC. Microscopically, the typical features of the tumors were microcystic arrangement and formation of adenomatous structures. Microcystic areas were composed of smaller eosinophilic and bigger pale cells having cytological appearance typical of conventional CRCC. Cytological features of the adenomatous structures were mostly different from those of conventional CRCC. They had a typical columnar arrangement with nuclei positioned at the base of the glandular structures and a small amount of a deeply eosinophilic cytoplasm often endowed with brush border facing the lumen of the glands. In addition, all the tumors showed a brown pigmentation. The pigmentation was located mostly extracellularly, where it formed pools of heavy deposits. Microscopic calcifications present in all cases formed psammoma bodies or else the calcifications were more extensive and amorphous in shape. Ultrastructurally, the cells showed features characteristic of CRCC: typical cytoplasmic vesicles were 100-700 nm in size and mitochondria had tubulovesicular, lamellar or circular cristae. Some tumor cells contained dark, variously sized electron-dense pigment granules. Neither melanosomes nor membrane-bound neurosecretory granules were seen. Using fluorescence in-situ hybridization probes for chromosomes 1, 2, 6, 10, 13, 17 and 21, the tumors revealed massive loss of tested chromosomes typical for conventional CRCC. Monosomy of chromosomes 1, 2, 6, 10, 13 and 21 was found in 100, 36, 91, 82, 82, 82 and 64% of cases, respectively. None of the cases showed mutation of exons 9, 11, 13 and 17 of the c-kit gene. The important feature of pigmented microcystic chromophobe renal cell carcinoma is a relatively benign biological behavior and the absence of distant metastases and sarcomatoid transformation.

Comparison between degree of carotid stenosis observed at angiography and in histological examination.

BACKGROUND: The generally accepted indications for carotid endarterectomy are the clinical picture and degree of per cent stenosis of the carotid artery. Despite the fact that stenosis measurement is defined, the methods vary considerably. The correlation of particular methods, especially angiography and duplex sonography, has been repeatedly demonstrated. However, the correlation between any technique and true anatomical stenosis, as evaluated on the surgical specimen, has been only anecdotally reported. METHOD: During carotid endarterectomy, the atherosclerotic plaque was removed in one piece and subsequently stored and histologically processed. The histological slides were evaluated under an optical microscope, scanned and the slide with maximum stenosis was determined using a planimetric program. Both the minimal lumen area and the area of the whole plaque were measured. The stenosis was calculated using the planimetric method. On the maximum stenosis slice, the minimal diameter and the diameter of the whole plaque were also measured. Angiographic images were scanned and the per cent stenoses were remeasured, according to the NASCET and ECST criteria. In total, of 147 cases, all above-mentioned parameters were obtained. Student's t tests for paired samples were used to evaluate the results. FINDINGS: The t-tests indicated significant differences between the per cent stenosis as measured on the anatomical specimen and on the angiogram (p<0.05). The results indicate that the angiographic measurement underestimates the degree of in-situ anatomical stenosis. The underestimation was more marked the less the degree of stenosis. CONCLUSIONS: Our study finds that per cent stenosis measurement obtained by angiography with NASCET or ECST methods does not reliably reflect the anatomical degree of per cent stenosis, which makes questionable the rigorous following of percentage stenosis using angiography as the sole indicator for carotid endarterectomy in all cases.

Cystic fibrohistiocytic tumours presenting in the lung: primary or metastatic disease?

AIMS: Cystic fibrohistiocytic tumour of the lung is a rare proliferative process. Its histogenesis is uncertain, but evidence suggests that some cases represent metastatic disease from apparently indolent skin lesions, namely cellular fibrous histiocytomas. This study presents four cases and reviews the literature concerning this pattern of disease and its aetiology. METHODS AND RESULTS: All patients were male (age range 35-54 years). Two presented with recurrent haemoptysis. Two cases had histories of cutaneous fibrohistiocytic lesions in the chest wall, excised 10 and 23 years prior to presentation with lung disease. Imaging data showed multiple bilateral cystic lung lesions in all four patients with nodular cavitating opacities seen on high-resolution computed tomography scans. Microscopy showed variably dilated thin-walled cystic airspaces lined by cuboidal epithelium and an underlying layer of mildly pleomorphic spindle cells with slightly wavy morphology and storiform architecture, admixed with inflammatory cells. Tumour cells stained for CD68 in three of four cases. All cases were negative for CD34. All patients were alive with disease, although one required pneumonectomy for intractable haemoptysis. CONCLUSION: This study and a review of published cases show that the majority of cystic fibrohistiocytic tumours of the lung probably represent metastases from cellular fibrous histiocytomas. However, rare cases may be either primary in origin or the primary site remains occult; the term cystic fibrohistiocytic tumour remains appropriate for such cases.