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

Comparison of the prognoses of laryngeal preneoplastic lesions based on Ljubljana and World Health Organization classifications

BACKGROUND

The aim of this study is to evaluate the prognosis of patients with laryngeal preneoplastic lesions based on Ljubljana classification (LC), Revised LC, World Health Organization Dysplasia System (WHO-DS) 2005 and WHO-DS 2017.

METHODS

Patients diagnosed with a laryngeal preneoplastic lesion in our clinic between 2005 and 2018 were included in the study. Biopsy preparations of patients were reexamined by the pathology unit and classified based on LC, Revised LC, WHODS 2005, and WHO-DS 2017. Patients with carcinoma were identified during follow-up. The prognosis of preneoplastic lesions was statistically analyzed based on carcinoma development and duration using these four different classifications.

RESULTS

Carcinoma developed in 16 of 142 patients after repeated biopsy. The risk for carcinoma development was found to be more statistically significant in atypical hyperplasia than in squamous cell hyperplasia and basal-parabasal cell hyperplasia according to LC (p: 0.027 and 0.035), no statistically significant difference was observed between squamous and basal-parabasal cell hyperplasia and CIS groups. The risk of carcinoma development was more statistically significant in high-grade squamous intraepithelial lesion (SIL) than in low-grade SIL according to revised LC (p: 0.04); in severe hyperplasia than in other groups according to WHO-DS 2005; and in highgrade dysplasia than in low-grade dysplasia according to WHO-DS 2017 (p: 0.013). The Cox regression analysis demonstrated that the risk of developing carcinoma statistically increased with age in all classifications, independent of the severity of dysplasia (p < 0.01). According to Cox regression analysis, there was no effect of sex on carcinoma development.

DISCUSSION

: In revised classifications, such as the revised LC and WHO-DS 2017, it is seen that facilitating clinical use is achieved by reducing the number of subgroups by combining the subgroups that do not statistically differ in terms of carcinoma development.

Oral Epithelial Dysplasia: A Review of Diagnostic Criteria for Anatomic Pathologists

Oral epithelial dysplasia (OED) represents a spectrum of histologic changes in the oral cavity mucosa that has the potential to transform into oral squamous cell carcinoma. Predicting the risk of malignant transformation is predominantly based on clinicopathologic correlation, histologic examination and grading. OED often poses a diagnostic challenge, primarily due to its histologic mimics and a large number of terminologies used in the literature. The grading system for OED is also fraught with significant interobserver variability. This review summarizes the essential clinical and histopathologic features of OED and its mimics. Practical preanalytical, analytical, and postanalytical considerations for anatomic pathologists are discussed to improve the diagnostic accuracy and increase the reproducibility in the grading of OED.

Development of head and neck pathology in Europe

This review gives a brief history of the development of head and neck pathology in Europe from a humble beginning in the 1930s to the explosive activities the last 15 years. During the decades before the introduction of immunohistochemistry in the 1980s, head and neck pathology grew as a subspeciality in many European countries. In the late 1940s, the Institute of Laryngology and Otology with its own pathology laboratory was founded in London, and in 1964 the World Health Organization (WHO) International Reference Centre for the Histological Classification of Salivary Tumours was established at the Bland-Sutton Institute of Pathology, also in London. International collaboration, and very much so in Europe, led to the publication of the first WHO Classification of Salivary Gland Tumours in 1972. In the 1960s, a salivary gland register was organised in Hamburg and in Cologne the microlaryngoscopy was invented enabling microscopic endoscopic examination and rather shortly afterwards a carbon dioxide laser attached to the microscope became established and laryngeal lesions could be treated by laser vaporisation. During the last three decades, the use of immunohistochemistry supplemented with cytogenetic and refined molecular techniques has greatly facilitated the pathological diagnostics of head and neck lesions and has had a huge impact on research. Collaboration between different European centres has drastically increased partly due to establishment of scientific societies such as the Head and Neck Working Group (HNWG) within the European Society of Pathology and the International Head and Neck Scientific Group (IHNSG). A very large number of European pathologists have contributed to the 2nd, 3rd and 4th WHO books, and are involved in the upcoming 5th edition. Accredited educational meetings and courses are nowadays regularly arranged in Europe. Numerous textbooks on head and neck pathology have been written and edited by European pathologists. The increased collaboration has created larger series of tumours for research and new entities, mainly defined by their genetic abnormalities, are continuously emerging from Europe, particularly regarding salivary gland neoplasms and "undifferentiated" sinonasal tumours. These findings have led to a better and more precise classification and open the possibilities for new treatment strategies.

A Preliminary Study on Automatic Characterization and Classification of Vascular Patterns of Contact Endoscopy Images

The structure and organization of blood vessels in the vocal fold go through changes during the advancement from healthy to benign and further on to malignant stages. Contact Endoscopy (CE) is an optical technique providing real-time information related to the vascular structure of laryngeal mucosa. However, this technique comes with subjectivity in the interpretation of vascular patterns. In this study, a novel automated approach is proposed for vessel pattern charac-terization and classification of larynx CE + Narrow Band Imaging (NBI) images. This method is mainly based on the computation of indicators related to the level of disorder of vessels. 12 features were extracted from the indicators and were fed into two supervised classifiers. Linear Support Vector Machine (SVM) and K-Nearest Neighbor (KNN) showed an accuracy of 95.76% and 93.92% for vascular patterns and 86.04% and 82.23% for larynx histopathologies classification, respectively. These promising results show that the proposed method can potentially solve the subjectivity issues of CE.

Oral epithelial dysplasia: Causes, quantification, prognosis, and management challenges

Oral epithelial dysplasia is a spectrum of architectural and cytological epithelial changes caused by accumulation of genetic changes, and is associated with an increased risk of progression to squamous cell carcinoma. It is a microscopic diagnosis of immense clinical importance. The initial reports of oral potentially malignant disorders with oral epithelial dysplasia transforming to oral cancer helped in understanding the nature of oral malignancies. Since then, clinical studies on oral potentially malignant disorders have combined microscopic findings of oral epithelial dysplasia to assess the malignant transformation potential of different grades of epithelial dysplasia. A significant amount of scientific literature has amassed on oral epithelial dysplasia relating to aspects of its diagnosis and management. However, the evidence base is weak as a result of the significant variability of published research. Poorly described study methods, variability in different oral epithelial dysplasia grading systems, inter- and intra-examiner variability causing issues of reliability, inadequate sample size, and inconsistent durations of follow-up are some of the methodological issues contributing to the failure to provide dependable information. Randomized clinical trials on the malignant transformation potential of oral epithelial dysplasia and its treatment outcomes are limited. This comprehensive literature review on oral epithelial dysplasia summarizes the scientific knowledge published in the scientific literature in English since its first description. The historical development, etiological factors, grading systems, diagnostic criteria, assessment of risk factors and prevention of malignant transformation, management principles of different grades of oral epithelial dysplasia (surgical and nonsurgical), recommendations on follow-up, and prognostic indicators are discussed in detail.

Transoral flexible laryngoscope biopsy: Safety and accuracy

Objective

To determine the accuracy of transoral flexible laryngoscope (TFL) biopsy and also to identify the safety as office based procedure in terms of complications.

Methods

This is a diagnostic study; the type of intervention is outpatient department based biopsy of laryngeal lesions. All patients seen in ENT outpatient department of Lyari General Hospital with suspicious lesions of Larynx were referred for Transoral Flexible Laryngoscopy Biopsy under local anesthesia. The specimens were sent for histopathology. The patients with benign pathology or carcinoma in situ were referred for direct laryngoscopy and biopsy. The sensitivity and specificity were calculated and the frequencies of complications were monitored to determine the complication rate.

Results

During the course of study a total of 47 patients underwent TFL biopsy in office settings. Out of these patients 16 patients were referred for direct laryngoscopy biopsy. The study population included 32 men and 15 women with ages ranging from 28 to 52 years and mean of (39 ± 6) years. Among 43 patients squamous cell carcinoma was the final diagnosis in 31 patients. In the rest of 12 patients’ dysplasia and benign lesion was the diagnosis in 9 and 3 patients respectively. These 12 patients underwent direct laryngoscopy biopsy and 10 of them diagnosed with invasive carcinoma rest had benign lesions. Hence the specificity was 75.6% and sensitivity was 100%. None of the patients developed any serious complication.

Conclusions

All patients with a suspicious lesion diagnosed by TFL biopsy as being benign or carcinoma in situ should have direct laryngoscopy for verification of the findings. But the results positive for carcinoma are reliable. In addition, this is a safe procedure.

Phonosurgical resection using submucosal infusion technique for precancerous laryngeal leukoplakia

OBJECTIVES/HYPOTHESIS

This study was designed to assess the feasibility of the submucosal infusion technique combined with microflap dissection as a radical therapeutic and diagnostic option for precancerous laryngeal leukoplakia.

STUDY DESIGN

Retrospective study.

METHODS

Severe dysplasia or carcinoma in situ was diagnosed after phonomicrosurgical dissections in 25 patients with unilateral laryngeal leukoplakia. Of these, 15 patients preferred no additional surgery (observation group), whereas 10 patients underwent further laser subligamental cordectomy (additional surgery group). The relationship between the initial surgical margin and histopathological characteristics of additionally excised tissues was assessed to evaluate diagnostic reliability. Disease control was assessed to determine the oncologic efficacy of the therapeutic procedure. Comparative multidimensional vocal assessments were performed in both groups to evaluate functional advantages of one-stage excision.

RESULTS

After the initial phonomicrosurgical resection, three patients had residual dysplastic lesions near the vocal process and anterior commissure, whereas three other patients had lesions suspicious for recurrence. No postoperative malignant transformation was observed in any patient. Although well-preserved vocal function was observed in the observation group, vocal quality deteriorated shortly after laser surgery in the additional surgery group. Regarding acoustics, aerodynamics, and quality-of-life evaluations, statistically equivalent scores were observed between the observation and control groups, whereas scores were inferior in the additional surgery group than in the control group.

CONCLUSIONS

Phonomicrosurgical resection may be a therapeutic option with oncologic efficacy against precancerous laryngeal leukoplakia. This radical management might achieve more satisfactory postoperative vocal function.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:153-158, 2017.

Laryngeal Squamous Intraepithelial Lesions: An Updated Review on Etiology, Classification, Molecular Changes, and Treatment

Laryngeal carcinogenesis is a multistep process, characterized by an accumulation of genetic changes associated with architectural and cytologic alterations, ranging from squamous hyperplasia to carcinoma in situ and encompassed by the terminology of squamous intraepithelial lesions (SILs). The etiology, classification, genetic changes, and malignant progression of these lesions are reviewed. Tobacco remains the principal etiological factor with gastroesophageal reflux disease recently considered as a possible factor. In contrast, there is little evidence that microbiological agents, especially human papillomavirus infection, are frequently involved in laryngeal carcinogenesis and probably <10% of SILs are driven by biologically active human papillomavirus infection. Light microscopy, despite a degree of subjectivity, remains the mainstay of accurate diagnosis, prognosis, and guidance for a patient's treatment. The currently used classifications, the dysplasia system, squamous intraepithelial neoplasia, and the Ljubljana classification, reflect different standpoints on this important topic. The modified Ljubljana classification, with good interobserver agreement, could be considered as a proposal for a unified classification of laryngeal SILs. This review also briefly discusses recently discovered genetic changes, such as CDKN2A and CTNNB1 genes, and chromosome instability of chromosomes 1 and 7; however, none of these can at present improve histologic diagnosis. Malignant progression of precursor lesions varies from 2% to 74%, according to different studies. Cold-steel microinstruments, CO2 laser, and radiotherapy are used to treat the different grades of precursor lesions. There is as yet no worldwide agreement on the treatment of high-grade lesions and carcinoma in situ.

Chemoprevention targets for tobacco-related head and neck cancer: past lessons and future directions

Progress toward identifying an effective chemopreventive agent to reduce the incidence of head and neck squamous cell carcinoma (HNSCC) has been limited by poor efficacy and intolerable toxicity profiles. In this review, we summarize the biological basis of HNSCC chemoprevention, and outline challenges associated with identifying appropriate high-risk HNSCC populations for chemoprevention studies. We discuss findings and lessons learned from clinical trials that have investigated micronutrient and molecular targeting interventions. Finally, we introduce the concept of green chemoprevention, interventions based upon whole plant foods or simple extracts that may represent a safe and cost-conscious option for the next generation of studies. As our scientific understanding of HNSCC reaches new levels, the field is poised to develop chemoprevention studies based on rigorous biological validation with accessibility to all affected individuals regardless of socioeconomic barriers.

Oral premalignancy: the roles of early detection and chemoprevention

Premalignancy and chemoprevention studies in head and neck cancer typically focus on the oral cavity. Avoiding or cessation of alcohol and smoking, early detection of potentially malignant disorders or cancer, and early detection of recurrent and/or second primary tumor form the basis of prevention of oral cancer. Analysis of tissue prospectively collected in evaluation of retinoids for chemoprevention trials allowed identification of molecular biomarkers of risk to develop oral cancer, loss of heterozygosity being the most validated one. Improving risk assessment and identification of new targets for chemoprevention represent the main challenges in this field.

[Aero-digestive tract squamous intra-epithelial neoplasia]

Aero-digestive tract squamous intra-epithelial neoplasia is a disease whose genetic and epigenetic features lead to clinical signs and well codified histologic features. This publication aims to review the molecular alterations which have been identified in these lesions, to clarify the clinical manifestations and to discuss the proposed histological classification.

Is severe dysplasia the same lesion as carcinoma in situ? 10-Year follow-up of laryngeal precancerous lesions

CONCLUSION

Our results showed that the behavior of moderate dysplasia lesions was more like that of severe dysplasia lesions, while severe dysplasia was very different from carcinoma in situ (CIS). CIS should be managed more aggressively than the other lesions. Mild dysplasia could not be viewed as a precancerous lesion of the larynx.

OBJECTIVE

This study aimed to identify the possibilities of the precancerous lesions of larynx (including mild dysplasia, moderate dysplasia, severe dysplasia, and CIS) progressing to invasive carcinomas and to highlight the importance of adequate management and follow-up strategies for these patients.

METHODS

A retrospective study of patients who had these preinvasive lesions in the larynx over a 10-year period was performed.

RESULTS

These patients were followed for a minimum period of 2 years from the initial diagnosis. In all, 86 patients were identified the cohort. Of these, 17 (19.8%) patients developed carcinoma: 0 of 22 with mild dysplasia, 5 of 25 (20%) with moderate dysplasia, 2 of 14 (15%) with severe dysplasia, and 10 of 25 (40%) patients with CIS progressed to invasive cancers (p = 0.001). Over 50% of cases progressed 3 years after the original biopsy. Only 1 of 86 (1%) died of the disease.

Common Lesions of the Larynx and Hypopharynx

Benign and malignant lesions of the larynx and hypopharynx present an interesting and diverse spectrum of diagnostic entities, which may be infrequently encountered in routine surgical pathology practice. This article places emphasis on illustrating the classical pathologic characteristics, differential diagnosis, clinical significance, and presentation of common lesions unique to these sites. The initial diagnosis of these lesions is via small endoscopic biopsy. Many of the entities have overlapping histologic features which necessitate optimizing the information available in a small sample. The focus of this article is to provide useful criteria to enable separating the more common types of lesions encountered in these sites.

Interobserver variability of laryngeal mucosal premalignant lesions: a histopathological evaluation

The objective of this study is to measure interobserver variability in the classification of laryngeal mucosal premalignant lesions by reassessing the histopathology of previously diagnosed cases and to determine the possible therapeutic consequences of disagreement among observers. Histopathological assessment of 110 laryngeal mucosal premalignant lesions was done by three pathologists. Each slide had to be classified according to the World Health Organization, Squamous Intraepithelial Neoplasia, and the Ljubljana Squamous Intraepithelial Lesions systems. After the independent assessment, a joint meeting took place. To assess the relation between histopathological grading and subsequent clinical management, we created a two- and a three-grade system besides one comprising all options. For all analyses, the SAS/STAT statistical software was used. The highest unweighted κ-values concerning the all-options system are observed for the Squamous Intraepithelial Neoplasia classification (0.28, 95% confidence interval 0.23-0.33), followed by the World Health Organization and Ljubljana classifications. For the two-grade system the Ljubljana classification shows the highest unweighted κ-values (0.50, 95%, 0.39-0.61), followed by the World Health Organization and Squamous Intraepithelial Neoplasia classifications. For the three-grade system, the unweighted κ-values are similar. The implementation of weighted κ-values led to higher scores within all three classification systems, although these did not exceed 0.55 (moderate agreement). Given the high level of consensus, simultaneous pathological assessment may be said to provide added value in comparison with independent assessment. In the current study, no clear tendency is observed in favor of any one classification system. The proposed three-grade system could be an improved histopathological tool because it is easier to correlate with clinical decision making and because it yields better unweighted κ-values and proportions of concordance than the all-options system. Furthermore, clinical management could benefit from assessment by more than one pathologist in suspected cases of dysplasia or carcinoma.

Oral premalignant lesions: from the pathological viewpoint

Under the widely used World Health Organization (WHO) classification for the pathological diagnosis of oral premalignant lesions, dysplasia, which is graded as mild, moderate or severe, and carcinoma in situ (CIS), which is a non-invasive carcinoma, are classified as precursor lesions of oral squamous cell carcinoma. Since the first edition (Wahi et al. International histological classification of tumours no. 4, WHO, Geneva, 1971), the criterion for CIS--that all epithelial layers are replaced by atypical cells--has remained unchanged. However, this dysplasia-carcinoma sequence theory was introduced from the viewpoint of pathological changes in the uterine cervix: in contrast, almost all premalignant lesions and CIS of the oral mucosa show superficial maturation and differentiation. Based on this recognition, the squamous intraepithelial neoplasia (SIN) classification and Ljubljana classification were included in WHO's latest edition published in 2005. Although the WHO classification is commonly used in Japan, recent developments in oral oncology have promoted modifications of the classification used in this country. In 2005, the Working Group of the Japan Society for Oral Tumours advocated iodine staining and proposed a modified SIN system, and in 2007, the Working Committee of the Japanese Society for Oral Pathology (JSOP) reported a new CIS (JSOP) definition that included differentiated-type CIS. In 2010, based on these studies, a new entity--oral intraepithelial neoplasia (OIN)--was included in the first edition of General Rules for Clinical and Pathological Studies on Oral Cancer. In this review, we focus on the OIN/CIS (JSOP) new classification of premalignant lesions in oral mucosa, which further advances the concept of SIN.

Inter-observer agreement in laryngeal pre-neoplastic lesions

In this series, laryngeal preneoplastic lesions were evaluated by the classifications of the World Health Organization (WHOC), Ljubljana (LC) and squamous intraepithelial neoplasia (SINC) by multiple observers. The inter-observer agreement (IA) by WHOC for laryngeal lesions had been previously evaluated, but to the best of our knowledge, there are no data for LC and SINC. H&E stained slides from 42 laryngeal biopsies were evaluated by fourteen participants according to WHOC and LC, and SINC was additionally applied by 6. The results were analyzed statistically. The diagnoses which were favored by most participants for each case, according to WHOC, were as follows: squamous cell hyperplasia (n = 5; 12%), mild dysplasia (n = 11; 26.2%), moderate dysplasia (n = 12; 28.6%), severe dysplasia (n = 7; 16.7%), carcinoma in situ (n = 5; 12%), and invasive squamous cell carcinoma (n = 2; 4.8%). There was a significant difference between the participants for all three classifications; some participants gave lower or higher scores than the others. The mean correlation coefficients (MCC) of the participants were higher for WHOC compared to LC (0.55 ± 0.15 and 0.48 ± 0.14, respectively). The mean linear-weighted kappa (wKappa) values of participants were not significantly different (0.42 ± 0.10, 0.41 ± 0.12 and 0.37 ± 0.07 for WHOC, LC and SINC, respectively). The kappa values in this series are in agreement with those in previous literature for WHOC, and the similar results obtained for LC and SINC are novel findings. Although the MCC of WHOC was higher, as the wkappa was not significantly different, the findings in this series are not in favor of any of the classifications for better IA for pre-neoplastic laryngeal lesions.

Epidermal growth factor receptor protein expression and gene amplification in normal, hyperplastic, and cancerous glottic tissue: immunohistochemical and fluorescent in situ hybridization study on tissue microarrays

AIM

To evaluate the importance of epidermal growth factor receptor (EGFR) protein overexpression and gene amplification in carcinogenesis of glottic cancer.

METHOD

In order to evaluate EGFR expression at protein and gene level, immunohistochemical (IHC) analysis and fluorescent in situ hybridization (FISH) were performed on tissue microarrays of laryngeal tissue (145 samples) -- 38 samples of normal mucosa, 46 samples of hyperplastic lesions, and 61 samples of cancerous lesions.

RESULTS

Membranous (mEGFR) and cytoplasmic (cEGFR) EGFR expression was significantly different between the analyzed groups. The differences were most striking in the suprabasal-transforming zone. IHC evaluation showed that high and low mEGFR staining contributed to the differentiation of dysplastic lesions, simple hyperplasia, and cancerous tissue, as well as between different degrees of atypia in hyperplastic lesions (P<0.050). EGFR gene amplification was not found in simple and abnormal hyperplastic lesions, but it was confirmed in 2/21 atypical hyperplasias, indicating that gene amplification can facilitate identification of malignant potential in hyperplastic lesions. In cancerous tissue, EGFR gene amplification was found in 8/50 samples. EGFR gene amplification was found in preinvasive cancer in one patient. In invasive carcinomas, gene amplification was not associated with stage or grade. Carcinomas with gene amplification showed significantly higher cEGFR expression (basal layer P=0.003; suprabasal layer P=0.002).

CONCLUSIONS

This study confirmed an increase in EGFR protein expression and gene amplification with the increase in biological aggressiveness of glottic lesions. A correlation between EGFR gene amplification and protein expression was established. Gene amplification proved to be an early event in glottic carcinogenesis, indicating its importance for glottic cancer prevention, early detection, and protocol selection.

Grading systems in head and neck dysplasia: their prognostic value, weaknesses and utility

BACKGROUND

Grading of dysplasia, including head and neck lesions, continues to be a hotly debated subject. It is subjective and lacks intra- and inter-observer reproducibility due to the insufficiency of validated morphological criteria and the biological nature of dysplasia. Moreover, due to the absence of a consensus, several systems are currently employed.

OBJECTIVES

The aims of this review are to: 1) Highlight the significance of dysplasia and the importance of a valid method for assessing precursor lesions of the head and neck. 2) Review the different histopathological classification systems for grading intraepithelial lesions of the head and neck. 3) Discuss and review quality requirements for these grading systems.

CONCLUSION

Regarding the different classification systems, data concerning the WHO classification system are the most available in current literature. There is no simple relationship or overlapping between the classification systems. Further studies should be done to see whether other systems have advantages above the current WHO system and to discover indications that could lead to an universal classification system for intraepithelial lesions of the head and neck.

Dysplasia of the upper aerodigestive tract squamous epithelium

Dysplasia of the oral, laryngeal and oropharyngeal stratified squamous epithelia is a microscopically defined change that may occur in clinically identifiable lesions including erythroplakia, leukoplakia and erythroleukoplakia, lesions that convey a heightened risk for carcinomatous progression. Dysplastic lesions have been classified microscopically according to degree of cytologic atypia and changes in architectural patterns, usually on a three part or four part gradation scale. Vocal cord epithelial lesions are graded according to either the Ljubljana or the World Health Organization (WHO) system whereas oral dysplasias are generally classified according to WHO criteria. Cytologically atypical cells are considered to represent precancerous changes predicting an increase risk for carcinomatous transformation. Inter- and intra-rater reliability studies among pathologists have disclosed low correlation coefficients for four part grading systems, whereas improved agreement is achieved (kappa correlation values) using the Ljubljana systems. Evidence forwarded by some studies supports the prognostic value of progressively severe dysplastic changes for carcinomatous transformation; however, some studies indicate that the presence of a clinically defined lesion without microscopic evidence of dysplasia also connotes increased risk for carcinomatous transformation. Loss of heterozygosity (LOH) at 3p and 9p microsatellite domains, DNA ploidy analysis and nuclear image analyses may have predictive value as molecular and histomorphological biomarkers.

[Application of Ljubljana classification in laryngeal precancerous lesions]

The diagnosis and treatment of laryngeal premalignant lesions has been frustrated because of failure to adequately define the histologic changes that may help in prediction of irreversible neoplastic transformation. To assess the grading of laryngeal hyperplastic epithelial lesion it was used a Ljubljana classification of histologic changes. It was done a retrospective study of 104 laryngeal hyperplastic lesions biopsies that were classified according to the Ljubljana classification comprising benign spinous layer augmentation (simple hyperplasia), benign basal and parabasal layer augmentation (abnormal hyperplasia), alteration of epithelial cells towards malignancy (atypical hyperplasia) and carcinoma in situ. One hundred and four biopsies with preneoplastic changes were reevaluated and classified according to Ljubljana classification. It was found 42 cases (40.4%) which showed simple, 38 (36.5%) abnormal, 21 (20.2%) atypical hyperplasia and 3 (2.9%) carcinoma in situ. Three cases of atypical hyperplasia (2.9% of all investigated cases) and one of abnormal (0.96%) progressed to invasive carcinoma during the observation ranging from 5 to 9 years (median 8.1). None of the cases classified as simple hyperplasia showed progression to malignancy. The Ljubljana classification focuses on the important clinical decision involving benign looking hyperplastic lesion that do not require strict follow-up (simple and abnormal hyperplasia); and "risky" epithelium that require close follow-up with repeated histologic assessment to recognize any malignant progression (atypical hyperplasia); and carcinoma in situ that requires fast and complete treatment. We suggest that the Ljubljana classification may give a reliable assessment of laryngeal hyperplastic epithelial lesions and can help in monitoring all those patients.

Postępowanie w stanach przedrakowych krtani – dylematy i znaki zapytania

BACKGROUND

Development of the laryngeal squamous cell carcinoma is taking place on the base of well-documented precancerous lesions. In histological examination precancerous lesions show dysplasia which may be reversible. The quick and proper diagnosis allows for applying the adequate and successful treatment.

AIM

Aim of the study was to evaluate the incidence of precancerous lesions of the larynx, their potential to evolve in relation to grade of dysplasia and discuss the pathologic findings.

MATERIAL AND METHOD

Retrospective analysis of histopathological documentation and ambulatory cards gathered in ENT Department between 1994-2003 was performed. The 173 patients with dysplasia and carcinoma in situ of vocal cord were analyzed.

RESULTS

The 2719 directoscopies were performed in 10 year period. Two out of 117 patients with moderate and 5 out of 27 with severe dysplasia were treated for laryngeal cancer during the follow up period. Out of these 117 patients the group of 46 patients was chosen, in whom more then 2 microlaryngoscopies were performed (more then 3 in 71,7%) with mean follow up period 4,2 years (from 4 month to 10 years). This group of 45 males and 1 female with dysplasia was carefully analyzed. The mean age was 59,6. Hoarseness from 2 weeks to 20 years (mean 17,5 month) was observed, but most often the patients were seen by the doctor in 2 month duration of complaints. The time between first presentation in Outpatient Department and direct laryngoscopy was from 1 day to 1,5 year, but as routine 2 week period was established. In 10 cases the up-grading of dysplasia was observed. The pathologic findigs were presented.

CONCLUSIONS

Quick, adequate (sensitive, specific) diagnostics of premalignancy in the glottis allows for effective and not humiliating treatment (phonosurgery, laser, partial laryngectomy). The rigid schedule of precancerous patient's treatment and follow-up should be drowning. The further diagnostic directions should attempt to find more sensitive methods than the routine histological examination for the assessment of the dysplastic lesions, allowing better evaluation of the risk for cancer development.

Immunohistochemical estimation of cell cycle phase in laryngeal neoplasia

We previously developed an immunohistochemical method for estimating cell cycle state and phase in tissue samples, including biopsies that are too small for flow cytometry. We have used our technique to examine whether primary abnormalities of the cell cycle exist in laryngeal neoplasia. Antibodies against the markers of cell cycle entry, minichromosome maintenance protein-2 (Mcm-2) and Ki67, and putative markers of cell cycle phase, cyclin D1 (G1-phase), cyclin A (S-phase), cyclin B1 (G2-phase) and phosphohistone H3 (Mitosis) were applied to paraffin-embedded sections of normal larynx (n=8), laryngeal dysplasia (n=10) and laryngeal squamous cell carcinoma (n=10). Cells expressing each marker were determined as a percentage of total cells, termed the labelling index (LI), and as a percentage of Mcm-2-positive cells, termed the labelling fraction (LF). The frequency of coexpression of each putative phase marker was investigated by confocal microscopy. There was a correlation between Mcm-2 and Ki67 LIs (ρ=0.93) but Mcm-2 LIs were consistently higher. All cells expressing a phase marker coexpressed Mcm-2, whereas Ki67 was not expressed in a proportion of these cells. The putative phase markers showed little coexpression. Labelling index values increased on progression from normal larynx through laryngeal dysplasia to squamous cell carcinoma for Mcm-2 (P=0.001), Ki67 (P=0.0002), cyclin D1 (P=0.015), cyclin A (P=0.0001) and cyclin B1 (P=0.0004). There was no evidence of an increase in the LF for any phase marker. Immunohistochemistry can be used to estimate cell cycle state and phase in laryngeal biopsies. Our data argues against primary cell cycle phase abnormalities in laryngeal neoplasia.

Management of laryngeal dysplasia: a review

Laryngeal dysplasia is a common clinical concern. Despite major advancements in otolaryngology, a significant number of patients with the condition progress to invasive carcinoma. In the recent years, new diagnostic techniques such as autofluorescence and contact endoscopy have been applied to increase the accuracy of the laryngeal biopsies. Moreover, significant efforts have been made to correlate the histopathological appearance of the dysplastic samples to their clinical course. So far, a wide range of therapeutic strategies for different grades of dysplasia has been suggested by authors; however, there is a lack of outcome reviews. In the current review, the outcome of different therapeutic strategies for severe dysplasia and carcinoma in situ has been compared with statistical analysis. The paper also summarises the current knowledge of the alternative management methods as well as current areas of research in the chemoprevention of the condition. (1) Significant efforts have been made to develop new techniques to improve the accuracy of microlaryngoscopic assessment of laryngeal premalignancy. Comparative studies are required using microlaryngoscopy against the new techniques to evaluate their clinical utility. (2) The meta-analysis suggests a better local control rate with radiotherapy compared to other standard methods of management of dysplasia; however, functional impairment and complications associated with each of the standard treatments should be further evaluated.

Combined use of histopathology with touch smear cytology in biopsies of the larynx

The aim of this prospective study is to evaluate the effectiveness of combined use of histopathology with cytology in biopsies of the larynx. Biopsies taken for this purpose are studied by using two different methods and the results are evaluated. One hundred and thirty-five patients with suspected malignant laryngeal lesions were examined by direct microlaryngoscopy for primary diagnosis. Each lesion was biopsied first. Subsequently touch smear cytology was obtained from the biopsies. In all cases, cytologic slides (one or two per biopsy) were screened and compared to corresponding biopsies. Lesions were categorized as benign, laryngeal intraepithelial neoplasia and malignant. Results obtained were compared with surgical samples obtained from patients who have undergone surgery. In other cases, where surgery was not applied, results of the follow-up were evaluated. In larynx biopsies the results for histopathology were as follows: sensitivity 93.9%, specificity 100% and accuracy 96.3%. The results for cytology were as follows: sensitivity 82.5%, specificity 94.5% and accuracy 87.4%. A comparison of cytologic evaluation versus histopathologic evaluation in laryngeal biopsies reveals that histopathology is superior. According to the study results, in 88.9% (120/135) of the cases the agreement between cytological and histopathological results was found. In two other cases (1.5%) cytologic evaluation contributed to the histopathologic diagnosis.

Aktuelle Klassifikation der Präkursorläsionen des oralen Plattenepithelkarzinoms

The WHO classification of oral tumours summarizes the precancerous squamous cell lesions under the term epithelial precursor lesions. For the first time three classification schemas that histologically categorize oral epithelial precursor lesions are used analogously. According to the WHO suggestion of 2005 the traditional schema of grading dysplasia as mild dysplasia, moderate dysplasia, severe dysplasia and carcinoma in situ continues to be used. In addition the concept of intraepithelial neoplasia is introduced as squamous intraepithelial neoplasia I-III. Squamous intraepithelial neoplasia III (SIN III) combines severe dysplasia and carcinoma in situ. The Ljubljana classification of squamous intraepithelial lesions was originally established to grade laryngeal epithelial precancerous lesions. The clear and succinct nomenclature and the simple clinical utility of the Ljubljana classification have also proven to be useful for oral epithelial precursor lesions: squamous cell (simple) hyperplasia; basal/parabasal cell hyperplasia (analogous to mild dysplasia and to SIN I); atypical hyperplasia (analogous to moderate-severe dysplasia and to SIN I-III and is also called risky epithelium); carcinoma in situ (analogous to WHO carcinoma in situ and to SIN III). Atypical hyperplasia (risky epithelium) and carcinoma in situ are defined as lesions requiring either total excision or close clinical monitoring.

Telomerase catalytic subunit in laryngeal carcinogenesis--an immunohistochemical study

We recently demonstrated that (1) telomerase catalytic subunit messenger RNA (mRNA) relative quantities increase progressively with the degree of laryngeal epithelial abnormalities and that (2) telomerase catalytic subunit gene re-expression represents an early event in laryngeal carcinogenesis. The aim of the study was to determine whether telomerase catalytic protein immunohistochemisty reflects telomerase catalytic subunit gene expression in different grades of laryngeal epithelial abnormalities and squamous cell carcinomas of the larynx. Telomerase catalytic protein was analysed immunohistochemically in 106 laryngeal epithelial tissue samples: 10 normal epithelia, 15 squamous cell hyperplasias, 14 basal/parabasal cell hyperplasias, 10 atypical hyperplasias, eight intraepithelial carcinomas and 49 squamous cell carcinomas. At least 200 nuclei of each lesion were quantified per slide and the number of positive signals per nucleus was expressed as a telomerase catalytic protein index. The mean telomerase catalytic protein index increased progressively with the degree of laryngeal epithelial abnormalities: from 0.17 in normal epithelia, 0.44 in squamous cell hyperplasia, 0.54 in basal/parabasal cell hyperplasia, 0.91 in atypical hyperplasia, 1.05 in intraepithelial carcinoma to 0.96 in squamous cell carcinomas. Statistical analysis revealed three different groups of laryngeal epithelial changes according to the number of telomerase catalytic protein signals per nucleus: (1) normal epithelium, (2) regenerative epithelium (squamous cell hyperplasia, basal/parabasal cell hyperplasia), and (3) atypical hyperplasia, intraepithelial carcinoma and squamous cell carcinoma (P<0.0033). Telomerase catalytic protein immunohistochemistry parallels well with telomerase catalytic subunit mRNA relative quantities in laryngeal carcinogenesis. In normal and regenerative laryngeal epithelia, telomerase catalytic protein is present in occasional basal/parabasal nuclei, becomes undetectable with maturation or differentiation of epithelial cells, and reflects the regenerative capacity of squamous epithelium. Nevertheless, several telomerase catalytic protein signals in the majority of nuclei in precancerous lesions, intraepithelial carcinomas and squamous cell carcinomas, are consistent with telomerase catalytic subunit gene re-expression, an early event in laryngeal carcinogenesis.

Divergent Patterns of Allelic Alterations in Premalignant Laryngeal Lesions Indicate Differences in the Impact of Morphological Grading Characteristics

OBJECTIVES

Classic histological grading and molecular genetic analysis of epithelial hyperplastic laryngeal lesions (EHLL) were correlated in an attempt to elucidate, which classic marker reflects best the gradual progression of laryngeal premalignant lesions as determined by an increasing number of molecular genetic aberrations.

METHODS

Thirty-two EHLL were grouped according to four grades of nuclear atypia, four degrees of epithelial maturation and three groups of overall and suprabasal mitotic activity. Overall and suprabasal proliferative activity were measured by MIB-1 immunostaining and staged according to four levels. Allelic imbalance was determined by PCR using 32 microsatellite loci at nine chromosomal arms.

RESULTS

Of the six classic criteria, only progressive mitotic indices correlated with allelic alterations in a remarkable variety of microsatellite markers, especially at chromosome 17p.

CONCLUSION

Using the number of allelic alterations as standard for assessment, this preliminary study gives first evidence that certain morphological criteria could reflect differently the gradual progression of premalignant laryngeal lesions with mitotic index being the most promising marker. Further studies with long-term follow-up are required to prove the predictive value of these criteria in daily practice.

Human telomerase catalytic subunit gene re-expression is an early event in oral carcinogenesis

AIMS

Detection of telomerase catalytic subunit (hTERT) mRNA has been used as a surrogate marker for estimation of telomerase activity. The exact role and timing of telomerase re-activation, a key enzyme implicated in cellular immortalization and transformation, in the multistep process of oral carcinogenesis is still unknown. The aim was to test the hypothesis that (i) quantitative rather than qualitative differences exist in the level of hTERT mRNA expression between normal oral mucosa, different grades of oral epithelial abnormalities and squamous cell carcinomas of the oral cavity, and that (ii) hTERT gene re-expression is an important, probably early event in oral carcinogenesis.

METHODS AND RESULTS

The relative quantity of hTERT mRNA was analysed in 45 frozen oral epithelia representing different morphological stages of oral carcinogenesis classified according to the Ljubljana classification and in 37 oral squamous cell carcinomas, using a commercially available LightCycler Telo TAGGG hTERT Quantification kit. hTERT mRNA was not detected in normal or reactive hyperplastic oral epithelia, but was present in 43% of atypical hyperplasias (premalignant lesions), 60% of intraepithelial carcinomas and 68% of oral squamous cell carcinomas. Statistical analysis revealed two groups of oral epithelial changes, with significant differences in the levels of hTERT mRNA expression: 1, normal and reactive hyperplastic oral epithelium, and 2, atypical hyperplasia, intraepithelial carcinomas and squamous cell carcinomas.

CONCLUSION

These data suggest that hTERT gene re-expression represents an early event in the multistep process of oral carcinogenesis, already detectable at the stage of precancerous oral epithelial changes. Nevertheless, other genetic aberrations appear to be necessary for progression of oral epithelial abnormalities towards invasive squamous cell carcinoma.

Adenosquamous carcinoma of the head and neck: criteria for diagnosis in a study of 12 cases

AIMS

Adenosquamous carcinoma (ASC) of the head and neck is an unusual neoplasm in which a general consensus with regard to diagnostic criteria has not yet been reached. In this study we report the clinicopathological results of 12 ASCs, with special attention to their histological and immunohistochemical characteristics in order to define this neoplasm more precisely.

METHODS AND RESULTS

All the patients were male with a peak incidence in the sixth decade of life. The tumours were located most frequently in the larynx and oral cavity, followed by the nasal cavity and pharynx. ASCs had two distinct histological components. The most extensive one was an usual keratinizing squamous cell carcinoma, arising from the surface epithelium, where characteristically severe dysplasia or carcinoma in situ was found in all cases. The second component was an adenocarcinoma, usually displayed in the deepest areas of the tumour. Evidence of origin from salivary or seromucinous glands was not found. Immunohistochemical studies demonstrated in most cases positivity of glandular differentiated areas for carcinoembryonic antigen (CEA) (11/12), CK7 (9/12) and CAM5.2 (7/12), whereas the squamous cell component was unreactive or reacted only focally for these markers. High-molecular-weight cytokeratin 34BE12 was positive in both components and CK20 was always negative. All cases showed high expression of Ki67 antigen. Most of them had overexpression of p53 (8/12) and DNA aneuploidy (10/12). Fifty percent of patients with ASC died of disease after a mean period of 23 months (range 12-35 months).

CONCLUSIONS

ASC of the head and neck is an aggressive neoplasm that originates in the surface epithelium of the upper respiratory tract. Severe dysplasia or carcinoma in situ is usually found and its recognition helps to make the diagnosis. In addition to mucin stains, positive immunoreactivity for CEA, CK7 and CAM5.2 helps to identify the glandular component.

Immunohistological comparison of the World Health Organization (WHO) and Ljubljana classifications on the grading of preneoplastic lesions of the larynx

There is still controversy about the classification of laryngeal preneoplastic lesions. In this study, we compared the World Health Organization (WHO) and Ljubljana histological classifications with regard to laryngeal epithelial hyperplastic-dysplastic lesions in a single series to determine their relation to statistically significant criteria when the mechanisms of neoplastic progression are considered. Emphasis was put on p53 expression, proliferative activity, and angiogenesis. Fifty-four laryngeal biopsies with preneoplastic changes were re-evaluated and classified according to both classifications. The streptavidin-biotin method was used for immunohistochemical staining for Ki-67, p53, and CD34 antibodies. A positive correlation was obtained between the histological categories and Ki-67, p53, and CD34 expressions using both classifications (Spearman's Correlation test). There was a significant difference between the histological categories of both the WHO and the Ljubljana classifications, when the expression of the three markers was compared (Kruskal Wallis test, p = 0.000 for each). Further evaluation revealed a statistically significant difference between all categories of both classifications, excluding the p53 overexpression scores and vessel counts in mild and moderate dysplasia categories (Mann-Whitney U-test, p = 0.209, and 0.091 respectively), and the p53 overexpression scores in severe dysplasia and carcinoma in situ categories (Mann-Whitney U-test, p = 0.249) of the WHO classification. Similarly, no significant differences were found between severe dysplasia and carcinoma in situ, as well as between atypical hyperplasia and carcinoma in situ categories using both classifications for the Ki-67 expression (Mann-Whitney U-test, p = 0.806, and 0.111, respectively). Our results suggest that regarding the mechanisms of neoplastic progression such as p53 expression and angiogenesis, the histological categories of the Ljubljana classification seem to depend on additional evidence. Therefore, we support the use of the Ljubljana classification.

Telomerase reactivation is an early event in laryngeal carcinogenesis

The exact role and timing of reactivation of telomerase, a key enzyme implicated in cellular immortalization and transformation in the multistep process of laryngeal carcinogenesis, is still unknown. We attempted to (1) determine that quantitative differences exist in the levels of telomerase catalytic subunit (hTERT) mRNA expression among different grades of laryngeal epithelial abnormalities classified according to the Ljubljana classification; (2) determine that telomerase reactivation is an important, most probably early event in laryngeal carcinogenesis; and (3) analyze whether the relative quantity of hTERT mRNA can be used as a molecular biomarker in the early detection of precancerous lesions. The relative quantity of hTERT mRNA, expressed as an hTERT index, was analyzed in 140 frozen laryngeal tissue specimens representing different morphological stages of laryngeal carcinogenesis by using a commercially available LightCycler Telo TAGGG hTERT Quantification kit. The presence and relative quantity of hTERT mRNA in laryngeal epithelium increases progressively with the degree of epithelial abnormalities. hTERT mRNA was detectable in 1/15 normal laryngeal epithelia (7%, mean hTERT index 0.02), 3/15 simple hyperplasias (20%, mean hTERT index 0.09), 10/27 abnormal hyperplasias (37%, mean hTERT index 0.18), 9/12 atypical hyperplasias (75%, mean hTERT index 0.74), 8/9 intraepithelial carcinomas (89%, mean hTERT index 1.82), and 53/62 invasive laryngeal squamous cell carcinomas (85%, mean hTERT index 2.51). Statistical analysis revealed two groups of laryngeal epithelial changes with significant differences in the levels of hTERT mRNA expression (P <.0033): (1) normal and reactive hyperplastic laryngeal epithelium (simple and abnormal hyperplasia) and (2) atypical hyperplasia (precancerous lesion), intraepithelial and invasive laryngeal squamous cell carcinoma. The results of the present study suggest that telomerase reactivation is an early event in laryngeal carcinogenesis, detectable already at the stage of precancerous laryngeal epithelial changes. Nevertheless, other genetic abnormalities appear to be necessary for progression of these epithelial abnormalities toward invasive laryngeal squamous cell carcinoma.

Aberrant expression of minichromosome maintenance protein-2 and Ki67 in laryngeal squamous epithelial lesions

Histological classification of laryngeal epithelial lesions is highly subjective, and methods of cytological detection are not well developed. Improved determination of aberrant cell cycle entry may allow increased objectivity in histological assessment and enable the development of less invasive diagnostic cytology tests. Sections of normal larynx (n=10), laryngeal dysplasia (n=20) and laryngeal squamous cell carcinoma (SCC) (n=10) were classified according to the Ljubljana classification and stained for markers of cell cycle entry, minichromosome maintenance protein-2 (Mcm-2) and Ki67. Expression patterns were compared using double labelling confocal microscopy. There was a correlation between Mcm-2 and Ki67 labelling indices (rho=0.93; 95% CI [0.84, 0.97]) and both markers showed increased expression from normal epithelium to SCC (Mcm-2, P=0.001; Ki67, P=0.0002). Importantly, there was minimal expression of Mcm-2 or Ki67 in the most superficial layers of normal larynx and abnormal or atypical hyperplasia, in contrast to carcinoma in situ and SCC. Clusters of Mcm-2/5-positive cells were present in cytological preparations from SCC, but not from those showing atypical hyperplasia or inflammation in non-neoplastic tissue. Minichromosome maintenance protein-2 staining may increase the objectivity and reliability of histological grading of laryngeal epithelial lesions. Laryngeal brushings, combined with immuno-enhanced liquid-based cytology, could be useful, as a less invasive approach, to the detection of laryngeal malignant and premalignant lesions.

The Ljubljana classification - its application to grading oral epithelial hyperplasia

INTRODUCTION

The diagnosis, prognosis and treatment of particular pathologic entities of the oral mucosa depend almost exclusively on the histologic changes in the epithelium. The basis for the classification of oral epithelial hyperplastic lesions should be their propensity to progress to invasive cancer.

MATERIAL AND METHODS

In a retrospective study, 135 biopsies of oral epithelial hyperplastic lesions from 115 patients were classified according to the Ljubljana classification, which has recently been introduced for the grading of laryngeal hyperplastic epithelial lesions.

RESULTS

Seventy nine cases (59%) showed simple, 42 (31%) abnormal and 11 (8%) atypical hyperplasia; carcinoma in situ was found in three cases (2%). During the follow-up, ranging from 3 months to 6 years (median 1 year), two cases of atypical hyperplasia progressed to invasive cancer, whereas none of the cases classified as simple or abnormal hyperplasia showed progression.

CONCLUSION

The present study suggests that the Ljubljana classification can be reliably applied for classifying oral epithelial hyperplastic lesions into different risk groups, which is essential for prognosis in order to plan therapy.

Matrix metalloproteinase-2 expression in laryngeal preneoplastic and neoplastic lesions

Matrix metalloproteinase-2 (MMP-2), a member of gelatinases, is particularly important in the digestion of nonfibrillary and denaturated collagens; thus, it may play a role in tissue remodeling and in the invasion of malignant cells. The expression of MMP-2 has not yet been described in preneoplastic lesions of the larynx thus far. The purpose of this study was to evaluate whether the expression of MMP-2 plays a role in early laryngeal carcinogenesis. Laryngectomy specimens of 20 invasive carcinoma cases were studied. The slides with atypical hyperplasia, carcinoma in situ, and invasive carcinoma were selected from laryngectomy specimens. On these slides, 23 atypical hyperplasia and 17 carcinoma in situ areas were identified. MMP-2 expression was scored immunohistochemically on paraffin tissue sections using the avidin-biotin-peroxidase method. MMP-2 expression in all three groups was statistically different. A sequential increase in MMP-2 expression correlated significantly with the hypothesis of multistep carcinogenesis. In contrast, MMP-2 expression was not related to tumor stage, lymph node metastasis, or differentiation in squamous cell carcinomas. In conclusion, this sequential increase in MMP-2 expression points to an altered expression of MMP-2 in early neoplastic transformation in laryngeal mucosa, followed by an increasing expression during the progression of the disease.

Consistency of histopathological reporting of laryngeal dysplasia. The Scottish Pathology Consistency Group

AIMS

Clinical management of premalignant and malignant lesions of the larynx is dependent on histopathological evaluation. The Scottish Pathology Consistency Group assessed interobserver variation in the evaluation of laryngeal dysplasia.

METHODS AND RESULTS

One hundred laryngeal biopsies ranging from normal to invasive carcinoma were assessed. The overall Kappa result of 0.32 was disappointing. However, agreement on those categories which dictate significantly different management was more favourable. The Kappa figure for mild dysplasia versus severe dysplasia/CIS was 0.7, the Kappa figure for mild dysplasia versus severe dysplasia/CIS and invasive carcinoma was 0.77. The Kappa figure for mild and moderate dysplasia versus severe dysplasia/ CIS and invasive carcinoma was 0.57. An attempt to use a two grade system gave a Kappa figure of 0.52.

CONCLUSIONS

Our group had a satisfactory agreement on the distinction of mild from severe dysplasia and on microinvasive carcinoma without any discussion as to histopathological criteria to be used. Clinical management--review endoscopy, repeat cord stripping, radiotherapy and laryngectomy--is in general dependent on histological assessment. Thus the agreement on categories which underpin clinical management is reassuring. However, assessment of moderate dysplasia remains problematic. An attempt to utilize a two grade system--low grade from high grade dysplasia/CIS--may have merit. The implications of the terminology used must be agreed among pathologists and clinicians working closely within clinicopathological cancer groups.

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.