[The Ljubljana classification of epithelial hyperplastic laryngeal lesions: a morphometric evaluation of nuclear pleomorphism]

Epithelial hyperplastic laryngeal lesions (EHLL) are associated, with a varying degree of "epithelial risk"- to develop invasive carcinoma. Several classifications have been proposed but none has received a total agreement. The 1999 Ljubljana classification distinguished four grades: simple, abnormal and atypical hyperplasia and in situ carcinoma (ISC). The first two grades are considered benign lesions; the ISC is the malignant lesion, while the atypical hyperplasia is considered a "risky lesion". This is characterized by alterations of epithelial cells towards malignancy, but not to the extent to be found in carcinoma cells. Such characteristics refer to cytomorphological (e.g., nuclear hyperchromatism, nucleoli, increased nuclear/cytoplasmic ratio) and architectural (e.g. stratification, orientation, maturation) features. In the Ljubljana scheme, nuclear pleomorphism is one of the most important features. We wanted to improve the importance of nuclear pleomorphism in the basal cells layer in different classes of EHLL using morphometrical analysis. We studied 8 cases of simple hyperplasia, 10 of abnormal hyperplasia, 10 of atypical hyperplasia and 8 of ISC using the software SAM (Shape Analytical Morphometry). The results were submitted to univariate statistical analysis. Nuclear dimensions (maximum diameter, perimeter and area) showed a progressive increase from simple to atypical hyperplasias to ISC, while abnormal hyperplasia showed the lowest values. On the contrary, analytical parameters related to nuclear contour irregularities and asymmetries showed their highest values in abnormal hyperplasia nuclei. There were no significant differences between atypical hyperplasia and ISC, while it was possible to differentiate abnormal hyperplasia from the others. In conclusion basal nuclei of atypical hyperplasia and ISC are similar so that other cytological and morphological architectural parameters are necessary to distinguish the two lesions. Abnormal hyperplasia seems to be the biological category of 'proliferative " benign laryngeal epithelium; simple hyperplasia refers to "stable" - irritative epithelium.

Quantitative measurement of telomerase catalytic subunit (hTERT) mRNA in laryngeal squamous cell carcinomas

We tested 30 laryngeal squamous cell carcinomas (LSCCs) and 30 matched control laryngeal samples from the same patients for the presence of human telomerase catalytic subunit (hTERT) mRNA by using the Roche LightCycler Telo TAGGG hTERT Quantification kit. The hTERT index was calculated to express the relative quantity levels of hTERT mRNA. hTERT mRNA was detectable in 10 out of 30 (33%) laryngeal tissues covered by normal and/or reactively hyperplastic laryngeal epithelium and 23 out of 30 LSCCs (77%). The mean hTERT indices were 0.15 for control non-cancerous laryngeal samples, 0.57 for grade I, 2.35 for grade II and 3.72 for grade III LSCCs. LSCCs without detectable hTERT mRNA (23%) tended to have lower grades of disease. No correlation was found between the levels of hTERT mRNA and tumour size or locoregional lymph node status. We believe that hTERT mRNA in normal and/or reactively hyperplastic laryngeal epithelium originates from the stem cells and corresponds to the self-renewal capacity of the squamous epithelium. However, the greater quantity of h TERT mRNA in LSCCs is the result of telomerase reactivation in the process of laryngeal carcinogenesis.

A mouse model of chronic bacterial lesions (a cotton trap) for studying oral bacteria-lymphocyte interactions

We established a mouse model of chronic bacterial infection (cotton trap) to get a deeper insight into interactions between immune cells and bacterial strains, that are most commonly isolated from periapical processes. We have used flow cytometry to identify the presence of intracellular cytokines of activated T cells collected from cotton traps, previously infected with different strains of bacteria and implanted subcutaneously into the back of the mice. We provide an evidence that anaerobic bacteria (Bacteroides sp.) and nocardiae are more effective in inducing cytotoxic immunity and Th1 response compared to oral streptococci. Differences in immune response against anaerobic bacteria when compared to streptococci are probably dependent on some non-specific immune cell stimulation (e.g. by bacterial cell wall components), nevertheless the role of specific antigen-dependent immune mechanism can not be excluded.

Lead and zinc removal by laboratory-scale constructed wetlands

Constructed wetlands have the potential to trap and remove metals in mine wastewater. To determine the effectiveness of constructed wetlands for treating selected heavy metals in neutral mine effluent typical of lead mines, eight laboratory-scale constructed wetlands were set up to treat a synthetic, slightly alkaline, mine water containing 34.2 mg/L sulfate (SO4(2-)), 50 micrograms/L lead (Pb), and 300 micrograms/L zinc (Zn). After 45 days, one of the wetlands was switched to treat a synthetic smelter effluent with a much greater load of SO4(2-), sodium (Na+), and Pb. Temperature, hydraulic loading, and substrate composition typically did not affect treatment efficiency. The pH of the effluent was reduced from 8.0 to 8.5 to near neutral. The average removal in the eight wetlands was 90% for Pb and 72% for Zn. In wetlands operating on synthetic mine water, SO4(2-) was completely removed, likely by conversion to sulfide by sulfate-reducing bacteria. In the wetland operating on synthetic smelter effluent, only approximately 25% of 6 g/L influent sulfate was removed, and a breakthrough period of 4 days for Na+ was observed. Whole effluent toxicity assays on undiluted wetland effluent from wetlands treating mine and smelter water had 100% survival of fathead minnows and Daphnia magnia. Survival of Ceriodaphnia dubia was zero in undiluted effluent, but 75 to 100% survival was observed when the effluent was diluted to one-half strength.

Expression of tenascin and fibronectin in benign epithelial hyperplastic lesions and squamous carcinoma of the larynx

BACKGROUND

Tenascin (T) and fibronectin (FN) are glycoprotein components of the extracellular matrix presumably involved in cancer progression. We analyzed their expression in epithelial hyperplastic lesions (EHL) and squamous carcinoma (SC) of the larynx.

MATERIALS AND METHODS

Samples from resected larynges of 30 patients with SC, and laryngeal biopsies of 28 patients with EHL, SC or benign reactive conditions were included. Immunohistochemistry was performed with antibodies against T and FN.

RESULTS

T and FN gradually increased with the grade of EHL and were markedly increased in the majority of SC. In SC, expression of T and FN correlated with the degree of desmoplasia but was inversely related to the density of lymphocytic stromal infiltration and the differentiation of SC. T and FN were also positive in benign reactive conditions.

CONCLUSION

T and FN immunostaining provides useful information on epithelial-stromal interaction in laryngeal EHL and SC but should not be regarded as a reliable stromal marker of malignancy. Our results supported the postulated diversified nature of the tumor stroma.

Wegener's granulomatosis in the upper respiratory tract

Wegener's granulomatosis is a distinct clinico-pathological entity characterised by necrotising vasculitis of small arteries and veins in conjunction with the formation of granuloma in the upper and lower respiratory tracts, and glomerulonephritis. The vast majority of patients have antineutrophil cytoplasmic antibodies in the serum with a characteristic cytoplasmic pattern. However, in early phases of the disease only the upper respiratory tract may be affected, clinical and histological features may be nonspecific, and antineutrophil cytoplasmic antibodies not present. In this paper we present four patients with involvement of the upper respiratory tract suspicious for early Wegener's granulomatosis. We emphasise the significance of clinical, histological and serological parameters in the early detection of Wegener's granulomatosis.

The Ljubljana classification: a practical strategy for the diagnosis of laryngeal precancerous lesions

There is no internationally accepted classification of epithelial hyperplastic laryngeal lesions (EHLL). The majority of current classifications follow criteria similar to those commonly used for cervical epithelial lesions. However, the different etiology of laryngeal cancer and its particular clinical and histologic features necessitate a grading system more appropriate to this region. The Ljubljana classification of EHLL was devised in 1971 to cater to this requirement. Detailed criteria for histologic grading in this classification were formulated by a working group on EHLL of the European Society of Pathology in 1999. The system recognizes four grades: simple and abnormal hyperplasia are benign categories; atypical hyperplasia ("risky" epithelium) is potentially malignant, and carcinoma in situ actually malignant. The main features by which the proposed grading system differs from other classifications are: 1. the distinction between benign and potentially malignant lesions; 2. the positive separation of carcinoma in situ from atypical hyperplasia; 3. the lack of prognostic significance for any surface keratin layer. The eventual outcome of EHLL patients so graded justifies the proposal for separating the lesions into a benign group, showing malignant transformation in only 0.9% of cases, from a potentially malignant group showing malignant transformation in 11% of cases. For diagnostically difficult cases, supplementary techniques such as those using morphometry, immunohistochemical and molecular biology are advised to improve the accuracy of diagnosis and predictions of their biological behavior.

Clinical applicability of the Ljubljana classification of epithelial hyperplastic laryngeal lesions

The diagnosis, prognosis, and choice of treatment of various laryngeal lesions depends almost entirely on the interpretation of changes in the covering epithelium. These abnormalities, referred to as epithelial hyperplastic laryngeal lesions, have been graded according to the Ljubljana classification into simple, abnormal and atypical (risky epithelium) hyperplasia and carcinoma in situ. The aim of this study was to evaluate the clinical applicability and prognostic value of this classification and to determine the incidence of malignant transformation. A retrospective clinical-pathological analysis was performed in a series of 4167 patients with 4574 biopsies, treated from 1979 to 1994. Simple (benign prickle cell) hyperplasia was the predominant grade in nodules, polyps, Reinke's oedema, granulomas, and papillomas, accounting for 37.6-68.6% of cases. In chronic laryngitis, abnormal (benign basal cell) hyperplasia was predominant with 43.9% of cases. Atypical ('risky') hyperplasia was observed almost exclusively in patients with chronic laryngitis (16.1%) and papillomas (10.1%), and only exceptionally in patients with vocal cord nodules (0.9%) and Reinke's oedema (0.3%). The percentage of malignant transformation in atypical hyperplasia was 11.6% (13/112 patients in 2-12 years), while in simple and abnormal hyperplasia, it was 0.3% (8/2920 patients in 1.5-11 years). The data support the concept of the Ljubljana classification dividing epithelial hyperplastic laryngeal lesions into benign (simple and abnormal hyperplasia), potentially malignant (atypical hyperplasia) lesions and carcinoma in situ.

Laryngeal granuloma: characteristics of the covering epithelium

The purpose of the present study was to evaluate the biological behaviour of the marginal epithelium, that proliferates and eventually covers laryngeal granulomas, and to reveal the applicability of the recently re-introduced Ljubljana classification when reporting reactive epithelial hyperplastic lesions. A retrospective clinical and histomorphological analysis was performed on 149 laryngeal granuloma biopsies. Epithelial changes were classified according to the Ljubljana classification into normal epithelium; simple, abnormal, or atypical hyperplasia; and carcinoma in situ. Atrophic epithelium, not evaluated separately in the Ljubljana classification, was additionally assessed. Simple hyperplasia was found in 98 cases (65.8 per cent), abnormal hyperplasia in seven (4.7 per cent), atrophic epithelium in 24 (16.1 per cent), and normal squamous epithelium in 20 (13.4 per cent). Atypical hyperplasia and carcinoma in situ were not observed. The results of our study clearly showed that the proliferation of the covering epithelium mostly in the form of simple hyperplasia, is entirely reactive and therefore reversible. No epithelial hyperplastic lesions were found that were previously described to be associated with an increased risk of malignant alteration, namely atypical hyperplasia and carcinoma in situ. However, since an initial growth of an invasive malignant neoplasm might macroscopically imitate the appearance of laryngeal granuloma, a histological examination in all aetiological forms of laryngeal granulomas is required. By clearly discerning the benign nature of epithelial changes in laryngeal granulomas, the recently re-evaluated and further formulated Ljubljana classification may also influence the clinical handling of patients.

Rapid extraction of DNA from archival clinical specimens: our experiences

The analysis of DNA extracted from archival clinical specimens using polymerase chain reaction represents the basis of a variety of research and diagnostic protocols in medicine. However, the selection of optimal DNA extraction method is critical if such an analysis is to be successful. Recently, we have evaluated a number of rapid DNA extraction protocols in order to find the most suitable method for routine processing of the most common archival materials in pathological and cytological laboratories: paraffin-embedded tissues and Papanicolaou- or Giemsa-stained smears. Our results demonstrate that rapid DNA extraction methods have comparable DNA extraction efficiencies with standard DNA isolation protocols on archival clinical specimens with the exception of Giemsa-stained smears.

Chromosomes 7,17 polysomies and overexpression of epidermal growth factor receptor and p53 protein in epithelial hyperplastic laryngeal lesions

PURPOSE

To visualize directly a sequence of genetic changes underlying the entire spectrum of epithelial hyperplastic laryngeal lesions (EHLL) and laryngeal cancer by the use of non-isotopic in situ hybridization (ISH) for chromosomes 7 and 17 in correlation with overexpression of p53 protein and epidermal growth factor receptor (EGFR). The specific aim was to compare the results and prognostic significance between the two types of EHLL: isolated, mainly atypical hyperplasia or risky epithelium, and EHLL associated with squamous cell carcinoma (SCC).

PATIENTS AND METHODS

59 tissue specimens of EHLL obtained from 34 patients, graded according to the Ljubljana classification into simple (SH), abnormal (AbH) and atypical hyperplasia (AtH), and carcinoma in situ (CIS) were included in the study. Non-fluorescent ISH for chromosomes 7 and 17 was performed by biotinylated alpha-satellite DNA probes. Immunohistochemical staining for EGFR and p53 protein was analyzed on the same tissue samples.

RESULTS

Polysomy for both chromosomes increased in correlation with progressive grades of EHLL. The most important finding was the statistically significant difference in chromosome copy numbers between the isolated AtH and AtH associated with SCC. Overexpression of EGFR and p53 protein was found in 61 (36/59) and 52% (31/59) of cases, respectively. The immunoreactivity for both markers increased with the grade of lesions, but the staining pattern was not so uniform in isolated EHLL. On the other hand, the immunoreactivity was expressed more constantly in EHLL adjacent to SCC.

CONCLUSIONS

Numerical changes in chromosomes 7 and 17 might be associated with an upregulation of EGFR and p53 genes, and could contribute to critical events in laryngeal carcinogenesis. For daily practice, the cytogenetic and immunohistochemical analyses could be of assistance in distinguishing between low- and high-risk groups of AtH. However, the isolated forms of atypical hyperplasia need considerable further study by evaluating genetic changes with the described methods regarding their ultimate transformation to carcinoma.

Eph receptors and ephrin expression in cranial motor neurons and the branchial arches of the chick embryo

Cranial motor axons navigate along a variety of pathways to their targets in the periphery of the head. Whereas somatic motor axons innervate tongue and eye muscles, visceral motor axons innervate parasympathetic ganglia, and branchiomotor axons innervate the branchial arches. The formation of these diverse pathways must depend upon molecules present in the environment traversed by growing axons. We have analyzed the potential roles of the ephrin ligands and their Eph tyrosine kinase receptors during cranial motor neuron development and axon pathfinding, by investigating expression patterns of these molecules at relevant stages in the chick. We detected expression of EphA3 and EphA4 among trigeminal and facial motor neurons, at times when these neurons are projecting to their muscle targets in the branchial arches. Corresponding ephrin-A ligands for these receptors were found to be expressed in specific regions of the arches during the same period, implicating ephrin-mediated interactions in cranial motor axon pathfinding.

Criteria for grading in the Ljubljana classification of epithelial hyperplastic laryngeal lesions. A study by members of the Working Group on Epithelial Hyperplastic Laryngeal Lesions of the European Society of Pathology

AIMS

To validate histological criteria for the grading of epithelial hyperplastic laryngeal lesions (EHHL) (dysplastic laryngeal lesions), we used a system that had been devised and tested in Ljubljana, Slovenia over many years and was felt to be more appropriate to laryngeal pathology than is the commonly-used model of intraepithelial neoplasia in the cervix.

METHODS AND RESULTS

Vocal cord biopsies of 45 patients with a broad spectrum of EHLL were reviewed. Detailed histological criteria were formulated for each of the four grades of EHLL in the Ljubljana classification, comprising simple hyperplasia (benign spinous layer augmentation), abnormal hyperplasia (benign basal and parabasal layer augmentation), atypical hyperplasia (risky for malignancy) and carcinoma in situ (actually malignant, but without invasion).

CONCLUSIONS

Using these criteria a high degree of concordance of histological diagnoses of grading levels for the Ljubljana classification was achieved between the pathologists of the Working Group. The system was found to be more precise for routine diagnostic work than the others in vogue. The different grades of the Ljubljana classification correspond to significantly different levels yielded in each grade by the semiobjective methods of quantitative morphometry and immunohistochemistry.

Cervical metastases of head and neck squamous cell carcinoma correlate with loss of heterozygosity on chromosome 16q

To assess the potential involvement of putative tumor suppressors or metastasis suppressors on chromosome 16q in head and neck squamous cell carcinoma (HNSCC), we have examined 42 primary HNSCCs for loss of heterozygosity (LOH) at 16q and correlated these findings with the occurrence of cervical nodal metastases and other clinical parameters. Seven of the 42 (17%) HNSCCs examined displayed LOH at chromosome 16q24. Three of the seven HNSCCs showed LOH at all of the informative loci analyzed along the chromosome arm, whereas the other four showed only loss of a subset of markers. When LOH at 16q was correlated with clinical parameters, there was no significant correlation with age, sex, clinical stage, T stage, N stage or survival. However, there was a correlation between LOH at chromosome 16q24 and involvement of cervical lymph nodes. Of the seven HNSCCs that had lost heterozygosity at 16q24, six had local metastases to lymph nodes indicating that LOH at 16q24 may have predictive value for the metastatic potential of HNSCCs.

Detection of human papillomaviruses in tissue specimens

During the past decade, molecular methods based on the detection of viral DNA have become a key tool for the detection of human papillomaviruses (HPVs) in tissue. The methods can be divided into two groups: those in which tissue destruction is unavoidable for the detection of HPV DNA, and those in which the detection of viral DNA is performed in a way that allows tissue morphology preservation. Polymerase chain reaction is currently the most sensitive method for HPV detection and an excellent research tool. However, because of frequent contamination problems and lack of standardization, it is not readily applicable to diagnostic laboratories. The recent improvements in in situ hybridization have made it possible for this method to become the most appropriate method for routine detection of HPVs in tissue. At present, however, the use of at least two independent HPV DNA detection methods is indispensable for accurate determination of HPVs.

p53 protein overexpression in laryngeal squamous cell papillomas

We retrospectively investigated p53 protein immunoreactivity in 103 laryngeal squamous cell papillomas (LP) previously revealed to be human papillomavirus type 6 or 11 positive by in situ hybridization and/or the polymerase chain reaction. 21 LP failed to show any detectable level of p53 protein reactivity. In 45 cases only occasional strongly positive cells were observed in almost the whole thickness of the epithelium. In 26 LP, p53 protein immunoreactivity was found to be almost exclusively restricted to the basal epithelial cells. Finally, in 11 cases, basal cell layer immunoreactivity was accompanied by aggregates of p53-positive cells in the lower two thirds of the epithelium. This staining pattern was found predominantly in LP with atypical hyperplasia. We think that the observed patterns of p53 immunoreactivity in a majority of cases are a result of immunohistochemical detection of the stabilized wild-type p53 protein rather than the mutated p53 protein.

Tick-borne encephalitis: possibly a fatal disease in its acute stage. PCR amplification of TBE RNA from postmortem brain tissue

Tick-borne encephalitis has occurred regularly in Europe since it was first diagnosed in 1931 by Schneider. The mortality rate of patients with this disease is 1-2%. Death usually occurs in the acute stage of illness. A case report of a 28-year-old patient from Slovenia, who died shortly after the onset of tick-borne encephalitis, is described. The clinical course of disease, results of serological tests, neuropathological findings and polymerase chain reaction amplification of parts of viral genome from postmortem brain tissues are presented.

Langerhans and other immunocompetent cells in vocal cord epithelial hyperplastic lesions of patients with chronic laryngitis

The aim of the study was to evaluate the intraepithelial and stromal density of Langerhans cells and lymphoid infiltrate in different stages of carcinogenesis in vocal cord biopsies of 24 randomly selected patients with chronic laryngitis. The Langerhans and lymphoid cells were counted using immunolabelling with antibodies against CD1a, S100, CD3, CD20, and CD68 on paraffin-embedded sections of 24 archival laryngeal vocal cord mucosa biopsy specimens, 6 classified as simple, 7 as abnormal, and 11 as atypical epithelial hyperplasia. Results were statistically evaluated using the Kruskal-Wallis and Wilcoxon sign rank tests. The mean number of Langerhans cells and T lymphocytes per mm2 of cross-sectioned epithelium was found to increase from simple to atypical hyperplasia. There were statistically significant differences in Langerhans cell density between atypical hyperplasia and each of the other 2 grades, simple and abnormal hyperplasia, with p < 0.05. Our study suggests the involvement of immune mechanisms, particularly cell mediated, during laryngeal carcinogenesis and the possibility that the assessment of Langerhans cell density might be of prognostic significance.

Correlation of histomorphological criteria used in different classifications of epithelial hyperplastic lesions of the larynx

Different classifications of epithelial hyperplastic lesions of the larynx were proposed, but none of them has been generally accepted. The basic distinction among these gradings is evaluation of carcinoma in situ as a precancerosis or a distinct and separate entity. In the present study, atypical hyperplasia and carcinoma in situ are evaluated according to the proposed histomorphological criteria of the Kambic-Lenart classification. In an attempt to separate more objectively the histomorphological differences between these 2 lesions, in addition to traditional light microscopical examination, we also performed semiquantitative analysis with statistical evaluation using the Wilcoxon signed rank test. These results revealed a significant morphological and statistical difference comparing atypical hyperplasia and carcinoma in situ on the basis of the following criteria: abnormal mitotic figures (p = 0.005), mitotic activity (p = 0.014), nuclear pleomorphism (p = 0.006), cellular atypia (p = 0.005), dyskeratosis (p = 0.008), and stromal infiltration (p = 0.015). These results confirm our view that atypical hyperplasia and carcinoma in situ are 2 consecutive but different entities in the process of carcinonogenesis.

The interpretation of leukoplakia in laryngeal pathology

Leukoplakia is only a descriptive clinical term designating a white patch or plaque of the mucosa and must be complemented by histology. On the other hand, keratosis is an exclusively histological term denoting pathological production and accumulation of keratin on the surface of the laryngeal epithelium. Leukoplakia is usually keratosis, but not always. Keratosis can mask various epithelial changes, from simple hyperplasia to invasive squamous carcinoma and is only the superficially visible manifestation of an underlying pathological process. Keratosis means total replacement of superficial epithelial cells by keratin filaments, and dissolution of the nuclei. When nuclei are retained in keratinized cells, the process is termed parakeratosis. Therefore, keratosis can be classified as a separate entity only when histopathological examination reveals superficial keratotic changes accompanying a normal squamous epithelium. To identify the presence of keratosis in various benign laryngeal entities divided according to severity of epithelial abnormalities, and to determine whether keratosis has any prognostic value, we performed a retrospective analysis on bioptic material on 4,291 tissue specimens over a period of 15 years. Our results suggest that keratosis must be considered as only one sign of the disorder within the complex of other pathological changes and not as a distinct pathological entity. For this very reason, keratinization of the epithelial surface was not included among significant parameters used for the grading of epithelial changes into the particular group according to Kambic-Lenart classification.

Langerhans cells in human papillomaviruses types 6/11 associated laryngeal papillomas

Some studies have shown a reduced density of Langerhans cells (LCs) within epithelium infected by human papillomaviruses (HPV) types 16/18. However, data on a correlation between HPV types 6/11 infection and LCs have been missing. To solve this problem, we analysed 24 biopsy specimens of laryngeal papillomas, selected randomly, 20 multiple and 4 solitary. The presence of HPV 6 and 11 was proven by polymerase chain reaction (PCR) using 2 different sets of primers in 23 biopsy specimens. Abnormalities of the covering stratified squamous epithelium were graded according to the Kambic-Gale classification. LCs were immunohistochemically labelled with 2 different antibodies, CD1a and S100. Quantitative analysis was performed to determine the density of LC per mm2 in different grades of epithelial abnormalities covering laryngeal papillomas. Although no statistically significant differences in the mean number of LCs per mm2 of the cross-sectioned epithelium covering laryngeal papillomas were observed comparing simple, abnormal and atypical hyperplasia groups, the mean number of LCs per mm2 in laryngeal papillomas associated with HPV types 6/11 infection substantially exceeded that of the vocal cord surface epithelium in patients with chronic laryngitis.

Epidermal growth factor receptor, c-erbB-2 and p53 overexpressions in epithelial hyperplastic lesions of the larynx

An immunohistochemical analysis of overexpression of epidermal growth factor receptor (EGFR), c-erbB-2, and p53 proteins was performed on 43 biopsies of laryngeal epithelial hyperplastic lesions (EHLL), classified according to the Kambic-Lenart classification, and in 11 cases of laryngeal carcinoma (SCCL). The aim of the present study was to determine whether there is a correlation between the staining patterns of these proteins and different grades of EHLL, and to reveal their possible prognostic value. We compared the staining patterns of atypical hyperplasia adjacent to cancer with the same type of lesions which have not turned malignant. p53 and EGFR overexpressions were detected in 28/54 (52%) and 33/54 cases (61%), respectively, and tend to increase with the degree of epithelial changes. The intensity of staining in various grades of EHLL adjacent to cancer was more pronounced than the same type of lesions which have not progressed to cancer. c-erbB-2 was weakly positive in the majority of cases, and changed from predominantly membranous in simple hyperplasia to cytoplasmic staining in abnormal and atypical hyperplasias. There was no significant statistic correlation between the amount of positive cells for all proteins and the grade of epithelial abnormalities. We conclude that the overexpression of each biomarker itself adds little predictive value over routine histomorphology, and cannot be regarded as a reliable prognostic factor for EHLL. However, the histologic characteristics of atypical hyperplasia together with the immunostaining patterns of EGFR and p53 up to two-thirds or more of the epithelial thickness could be considered a reliable pattern which correlates with the progression to cancer.

Quantitative pathology of laryngeal epithelial hyperplastic lesions

We studied 40 laryngeal biopsies samples in order to ascertain the reliability of light microscopical criteria for subdividing laryngeal epithelial hyperplastic lesions (EHL) and carcinoma in situ as well as to determine the relationship between proliferative activity of their epithelial cells and the histological grade. The biopsies were divided into four groups in accordance with the Kambic-Lenart classification: simple, abnormal and atypical hyperplasia and carcinoma in situ. 10 cases in each group were included. The morphometrical analysis was carried out by a semiautomatic image analysis system. The proliferative activity was determined by the high percentage of cell nuclear antigen (PCNA) and Ki-67 positive epithelial cells and with counting nucleolar organizer regions (Ag-NORs) per nucleus. Our results suggest that measuring the nuclear area of the basal cells. augmented with basaloid cells and carcinomatous cells, is the most useful morphometrical method of differentiating three types of laryngeal EHL and carcinoma in situ, while the proliferative activity progressively increased with the degree of epithelial hyperplasia. Morphometrical methods and proliferative activity should be regarded as useful in conjunction with the traditional histopathological methods allowing more of objective grading of EHL.

Human papillomavirus infection and expression of p53 and c-erbB-2 protein in laryngeal papillomas

Laryngeal papilloma (LP) is the most frequent benign laryngeal epithelial tumor caused by human papillomaviruses (HPV) types 6 and 11. In the present study, we were interested in whether we can find any prognostic markers which might reflect the biological behavior of the covering epithelium in LP. We focused our attention on the determination of HPV infection, the detection of p53 protein, and c-erbB-2 protein in 24 biopsy specimens of LP. We confirmed the HPV 6 and 11 etiology in 23 of 24 LP. In these lesions the overexpression of p53 protein increased with the grade of epithelial abnormalities. The distribution of positive cells changed from scattered and focal, in simple and abnormal hyperplasia, to diffuse in atypical hyperplasia. It has been shown that in the presence of HPV types 6 and 11 found in LP, p53 can still preserve its tumor suppressor activity. Infection with HPV types 6 and 11 might therefore account for the significantly lower rate of malignant transformation in LP. Two staining patterns for c-erbB-2 protein were observed in the hyperplastic epithelium covering LP: membranous and cytoplasmic. With the increasing grade of epithelial abnormalities, cytoplasmic staining became predominant, and c-erbB-2 positivity sometimes occupied the whole epithelial thickness. This may represent either an alteration in the processing stability of the c-erbB-2 mRNA, gene amplification, or even an artefact.

Flow cytometric analysis of lymphocytes isolated from nasal polyps

We analyzed by flow cytometry the expression of IL-2 receptors (alpha subunit-CD25) and ICAM-1 adhesion molecules (CD54) on T cells and subsets (CD4, CD8) isolated from nasal polyp tissue in allergic and non-allergic patients. We found a significant increase in IL-2 receptor and ICAM-1 molecule expression on T cells isolated from nasal polyp tissue compared to peripheral blood lymphocytes. We also found a significantly increased expression of ICAM-1 molecules on CD8+ cells in non-allergic compared to allergic patients. The latter may reflect a difference in cytotoxic immune response between allergic and non-allergic patients, but the result should be confirmed in a more extensive study including cytokine and immunoglobulin analysis. We hope that it would enable us to obtain a deeper insight into the local immune events and further to clarify the etiology and pathogenesis of nasal polyps and their relation to allergy.

Human papillomaviruses: a study of their prevalence in the epithelial hyperplastic lesions of the larynx

This study investigated the prevalence of human papillomavirus (HPV) infection in various laryngeal epithelial hyperplastic lesions using the Kambic classification from simple hyperplasia to invasive squamous cell carcinoma. For detection of HPV infection polymerase chain reaction (PCR) with 3 different HPV consensus primer sets and in situ hybridization were used. The presence of the HPV DNA was detected in only 2 of the 88 specimens tested: HPV type 6 was detected in 1 case of simple hyperplasia and HPV type 16 in 1 case of invasive squamous cell carcinoma. In conclusion, our study suggests that most laryngeal epithelial hyperplastic lesions are not associated with HPV infection and that other pathogenic mechanisms are more important in the etiology of these lesions.

Overexpression of p53 protein in benign and malignant laryngeal epithelial lesions

This study investigated the immunohistochemical expression of p53 protein in various laryngeal lesions using Kambic's classification from simple hyperplasia to invasive squamous cell carcinoma (SCC), and analyzed the relationship between p53 protein overexpression and the severity of epithelial abnormalities. p53 overexpression was observed in 10/19 (53%), in 9/16 (56%), and in 9/13 (69%) cases of simple, abnormal, and atypical hyperplasia respectively, and also in 8/10 (80%) cases of SCC. The proportion of immunoreactive cells and staining intensity increased with the progression of the epithelial hyperplastic lesions. Our study confirms the association of p53 protein overexpression with laryngeal epithelial hyperplastic lesions which have the potential to transform into malignancy, but considering the follow-up of the patients, p53 expression cannot be considered a reliable prognostic factor for any group of laryngeal epithelial hyperplastic lesions regardless of the severity of the lesions.

Expression of Ki-67 antigen and proliferative cell nuclear antigen in benign and malignant epithelial lesions of the larynx

In an attempt to analyse the proliferative activity in benign and malignant laryngeal epithelial lesions, and to determine the relationship to their histologic grade, we studied the expression of proliferative cell nuclear antigen (PCNA) and Ki-67 antigen on 20 squamous carcinomas, and on 30 biopsies of epithelial hyperplasia categorized according to the Kambic-Lenart classification into simple, abnormal, and atypical hyperplasias. In simple hyperplasia, both antibodies stained the nuclei of the occasional cells in the basal layer. In abnormal hyperplasia (mild dyplasia), positive cells occupied up to a third, and in atypical hyperplasia (moderate and severe dysplasia) they occupied from two-thirds to the entire epithelial thickness. In squamous carcinoma, we have found a statistically significant correlation between its grade and the percentage of Ki-67-(p < 0.01) and PCNA-(p < 0.00001) positive cells. Our results suggest that the proliferative fraction progressively increases with the degree of epithelial hyperplasia and the grade of carcinoma. We conclude that the patterns of immunoreactivity to PCNA and Ki-67 antigen correspond to the histologic grade of both benign and malignant epithelial lesions of the larynx. This method should be regarded as a useful adjunct to traditional histological techniques allowing more objective grading of benign and malignant epithelial lesions.

Unusual inflamed thyroglossal cyst

The authors report a case of an unusual inflammatory reaction in a thyroglossal cyst. It consisted of broad papillary intraluminal projections covered by histiocytes and occasional multinucleate giant cells. This benign process should not be confused with a true papillary neoplasm, a rare complication of a thyroglossal cyst.

Laryngeal papillomatosis: molecular, histopathological, and clinical evaluation

Molecular, histopathological, and clinical studies were carried out on a series of 79 laryngeal papillomas (LP) from 36 patients in order to investigate the hypothesis that juvenile and adult LP may represent a biological entity causally related to Human papilloma virus (HPV) infection. Using in situ hybridization with biotin-labelled probes and polymerase chain reaction, we detected human papilloma virus (HPV) 6/11 in 28 of 29 juvenile LP, in 26 of 30 adult multiple, and in 17 of 20 adult solitary LP. None of LP was found to harbour HPV types 16, 18, 31, 33, and 51. There were no clear-cut histological differences between juvenile and adult LP, the presence of koilocytosis was equally observed in both, and there was no prevalent type of epithelial hyperplasia in either form, except that all three cases of atypical hyperplasias (precancerous lesions) were found among adult patients. During a 14 year follow-up, no carcinomatous transformation of LP was observed. All juvenile LP in our study had frequent recurrences of the disease, however, numerous surgical procedures were also required in 16 of 27 adult patients. Our study supports Lindeberg's hypothesis of a similar pathogenesis for all forms of LP caused by the HPV types 6/11.

Local immune response in hyperplastic lesions of the larynx

A retrospective morphologic and immunohistochemical study of 25 benign and 5 malignant laryngeal hyperplastic lesions was performed concerning a local immune response which might be characteristic and of prognostic value for each particular group of these alterations, using Kambic's classification, especially for precancerous and cancerous lesions. On paraffin and frozen sections, 7 monoclonal antibodies against various leukocytic antigens were used. CD43 and CD45RO T lymphocytes were the predominant cells in the infiltrates, and their frequency increased according to the degree of hyperplastic lesions. Next in frequency were CD4 cells, and a predominance of CD4 over CD8 cells was an obvious finding. The infiltration of CD68-, CD57-, and CD20-positive cells was generally weak. The intensity and composition of the local reaction in all cases of atypical hyperplasias was nearly identical, regardless of their subsequent behaviour. No apparent cytotoxic effects on the epithelial cells, either in precancerous or in cancerous lesions, were observed. Thus, the immunocompetent cells in the epithelial and stromal tissue are most likely not an effective defense in preventing hyperplastic lesions from becoming malignant. It seems that laryngeal hyperplastic lesions do not provoke an essential defense immune response, but the present local inflammatory reaction might be a constituent part of etiologically different inflammations which may lead to unfavorable lesions.

p53 immunoreactivity in oligodendrogliomas

Data are presented on p53 protein presence in human oligodendrogliomas whose progress from low grade to anaplastic oligodendroglioma can be followed. Expression was evaluated by formalin-fixed paraffin-embedded section immunohistochemistry, using monoclonal PAb 1801 antibody. The frequency of p53 protein accumulation is related to the stage of tumor malignancy. All the samples (100%) of malignant oligodendrogliomas were positive for p53 protein. Of 14 type II oligodendroglioma samples, 9 were positive (64%) while among type I oligodendroglioma the positivity was 28%. The mean proportion of reactive cells was also higher in malignant oligodendrogliomas. However, mean intensity staining did not differ among various grades of tumors. Our results point to the direct link between p53 protein accumulation and the malignant stage of human oligodendrogliomas. However, the value of p53 protein accumulation in predicting malignant behavior of oligodendrogliomas requires further confirmation.

Laryngeal hyperplastic lesions, follow-up study and application of lectins and anticytokeratins for their evaluation

A retrospective study of 878 biopsy specimens from 692 patients with laryngeal hyperplastic aberrations was performed according to the Kambic-Lenart classification. Special attention was focused on 88 patients with persistent or recurring disease. In these carcinoma developed in 17 (2.4%) patients, 12 (1.7%) of whom had had atypical hyperplasia. We therefore propose that the term precancerosis, which so definitely implies cancer, should be replaced with the expression risky epithelium where nothing is determined in advance, but a careful follow-up of the patients is imperative. In particular cases of laryngeal hyperplastic lesions, mainly in abnormal and in atypical hyperplasias when the tissue specimens are cut tangentially, the exact identification and position of individual epithelial cells is essential. In such cases histochemical and immunohistochemical methods yield more precise evaluation. Lectins and cytokeratins provide good markers of epithelial maturation. These results contribute to a more useful evaluation of laryngeal hyperplastic lesions, crucial for the choice of adequate therapy.

Catastrophic thrombus development despite systemic heparinization during coronary angioplasty: possible relationship to nonionic contrast

Two cases of catastrophic thrombus formation during coronary angioplasty occurred shortly after the operators began using nonionic contrast. This occurred despite systemic heparinization, the adequacy of which was documented by activated clotting times (ACT). Both cases were resistant to balloon inflation and one was refractory to intracoronary thrombolysis. There is a considerable body of evidence documenting that low-osmolality contrast media, especially those that are nonionic, have less anticoagulant effect than standard contrast media. Several reports have also been published suggesting possible relationships between nonionic contrast and intravascular thrombus formation during coronary angiography and angioplasty. These data are reviewed and recommendations made for utilization of these contrast media.

Laryngeal chondrosarcoma: is conservative surgery adequate treatment?

A case of laryngeal chondrosarcoma in a 63-year-old woman is presented. The report illustrates most of the features of this rare neoplasm, the difficulties in the histopathological evaluation and supports the previous ones that recommend an initial conservative attitude towards low grade laryngeal chondrosarcomas.

Alterations in the laryngeal mucosa after exposure to asbestos

The laryngeal mucosa of 195 workers in an asbestos cement factory (Salonit Anhovo, Yugoslavia) and in a control group was examined. The factory manufactures asbestos cement products containing about 13% of asbestos (8% amosite, 12% crocidolite, and 80% chrysotile) of different provenance. Alterations in the laryngeal mucosa were more frequent in the factory workers than in the control group. The changes, mostly consistent with chronic laryngitis, were closely related to the degree of workplace pollution and less so to the duration of employment Ten workers exhibiting the most severe clinical changes underwent biopsy, the results of which showed histomorphological changes characteristic of hyperplastic chronic laryngitis. Four tissue specimens were examined also by scanning electron microscopy and in three of them asbestos fibres were found on the epithelial surface. No case of laryngeal carcinoma was identified. On the basis of our results it is thought that asbestos related changes of the larynx should receive more attention and that the use of the term "laryngeal asbestosis" is justified. The clinical picture is non-specific but in view of their frequency such changes should be considered a consequence of exposure to asbestos.

[Anatomical markers of Reinke's space and the etiopathogenesis of Reinke edema]

On the basis of histological examination of normal human larynges, the authors have defined the anatomical and histological features of Reinke's space. It is sharply demarcated by dense fibrous tissue in the anterior commissure, along the vocal process of the arytenoid and beneath the free margin of the vocal cord. The upper limit is not always sharply demarcated, and on the upper surface Reinke's space varies considerably in size. It may include a half of the upper surface of the vocal cord, reaching usually to the bottom of the laryngeal ventricle and occasionally extending to include also the inferior surface of the ventricular fold. The authors suggest that the upper boundary of Reinke's space is functional. On the basis of the morphologic structure of Reinke's space a hypothesis of aetiopathogenesis of Reinke's oedema was set up. The patient's attempt to compensate the hoarseness by the use of the false vocal cords forces the fluid within Reinke's space towards the free edge of the vocal cord.

Significance of keratosis and dyskeratosis for classifying hyperplastic aberrations of laryngeal mucosa

Retrospective study of 325 tissue samples of hyperplastic aberrations of the laryngeal mucosa by means of light and electron microscopy and immunohistochemical methods has demonstrated that superficial keratinization is not important for determining changes into precancerosis or "risky epithelium" or even for the progress from hyperplastic aberrations to carcinoma. The degree of keratinization of the epithelial surface in all three forms of hyperplastic aberrations is almost the same. In grouping the hyperplastic aberrations into "precanceroses" or "risky epithelium," the following morphologic changes have to be considered as extremely important factors: the occurrence of dyskeratotic cells, the basalification of the epithelium, and the response of the organism in the form of infiltration of immunocompetent cells in the subepithelial stroma.

Nasopharyngeal rhabdomyoma. Report of case (light and electron microscopic studies) and review of the literature

Rhabdomyoma is an extremely rare benign tumor originating from the skeletal or cardiac muscle cells. Only 87 cases of rhabdomyoma have been reported to date, 70% occurring in the head and neck areas. The authors present the fourth case of rhabdomyoma of the nasopharynx. The tumor appeared in an 18 year old woman with hypacusis. Examination of the epipharynx showed a 2 x 1,5 cm tumor, extending from torus tubarius down to the soft palate. Light microscopy disclosed areas and islands of polymorphous large cells with abundant eosinophilic cytoplasm. Cross striations were focally visible with special PTAH staining. Electron microscopy revealed parallel and haphazardly arranged fibrillar bands (myofibrils) with irregularly and periodically arranged densities corresponding to Z lines. The pecularities of our case were abundant cystically dilated rough endoplasmatic reticulum and the absence of cytoplasmatic glycogen.

Warty dyskeratoma of the vocal cord. First reported case

Warty dyskeratoma is a tiny, nodular lesion with a characteristic histologic picture that resembles that of Darier's disease. Until now, these changes have been described only on the skin and the mucosa of the oral cavity. To our knowledge, our case includes the first description of this lesion on the vocal cord. This study presents clinical and histologic features in detail, dealing also with the differential diagnosis, which is very important for distinguishing the warty dyskeratoma from the squamous cell carcinoma.

Laryngeal salivary duct carcinoma: a light and electron microscopic study

The light microscopic and ultrastructural features of a laryngeal salivary duct carcinoma are presented. By light microscopy, the neoplasm bore a marked resemblance to the infiltrating duct carcinoma of the breast. Ultrastructurally, the tumour was characterized by the presence of two principal types of cells, i.e. epithelial and myoepithelial cells, arranged in duct-formation.

Synovial sarcoma of the soft palate in a child: a light and electron microscopic study

An extremely rare case of synovial sarcoma localized in the soft palate of a 9-year-old boy is reported, describing all details noted during light and electron microscopic observation. All features characteristic of this mesenchymal tumour were evident in the light microscopy. Electron microscopy also confirmed the diagnosis. The text includes full particulars of the therapy administered.

Parotid involvement by Lennert's lymphoma

The authors report an unusual case of Lennert's lymphoma occurring in a 65-year-old patient. The tumour involved the right parotid gland and lymph nodes of the neck. It has responded to combined treatment (radiation and chemotherapy) extremely well.