The immunohistochemical phenotype, distribution and significance of proliferation of myofibroblasts in laryngeal epithelial hyperplastic lesions (EHL) and squamous carcinoma (SC) were analyzed.
...Samples of 42 resected larynxes and 40 laryngeal biopsies of EHL and SC were included. Immunohistochemistry was performed using antibodies against vimentin, alpha-smooth muscle actin (SMA), desmin and leukocyte common antigen.
Myofibroblasts were vimentin- and SMA-positive, and were found exclusively in SC, indicating that invasion beyond the basement membrane is necessary to evoke a myofibroblastic stromal reaction. We observed two patterns of stromal reaction in SC: one was characterized by a marked proliferation of myofibroblasts and desmoplasia, with scarce lymphocytic infiltration; this pattern tended to be associated with well- or moderately differentiated SC. The other was characterized by few myofibroblasts, weak desmoplasia, and dense lymphocytic infiltration; the latter pattern tended to be associated with moderately or poorly differentiated SC. The degree of myofibroblast proliferation was inversely related to the density of lymphocytic infiltration. Antibodies against SMA also stained stromal blood vessels, demonstrating a gradual increase of vessel density as the grade of EHL increased.
Immunohistochemical analysis of myofibroblasts provides useful information on the phenotypic characteristics of the stroma in laryngeal EHL and SC, and can serve as an additional marker of invasion.
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.
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.
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.
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.
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.
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.
Kambi V. Epithelial hyperplastic lesions-a challenging topic in laryngology.
Adequate diagnosis, treatment and prognosis of particular pathologic entities of the laryngeal mucosa depend entirely on ...the histological changes of the epithelium. The basis for the classification of epithelial hyperplastic lesions of the larynx (EHLL) is the progression of the histologic features of these lesions to cancer. Considering various criteria thought to be typical for the transformation of benign EHLL to carcinoma, they are most frequently classified into three different groups. However, difficulties begin with the lack of uniformity and inconsistency of terminology, and the fact that the histomorphological features and biological behavior are not always in accordance. It is emphasized that the surface keratosis in laryngeal pathology has no prognostic significance per se and that the term risky epithelium should replace the expression precancerosis. This term does not predict the evolution of the lesion in any way, and it does not exclude any possible future development; but it warns the laryngologist to exercise extreme caution and to follow the patient closely. Present knowledge of laryngeal cancer, its therapeutic options and consequences, force us to pay increasing attention to early detection and adequate treatment of EHLL
Poljak M, Gale N, Kambir V. 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 Kambi 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.
Cor A, Gale N, Kambi V. 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 Kambi -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.
Gale N, Zidar N, Karnbi V, Poljak M, Cör A. Epidermal growth factor receptor, c-erhB-2 and p53 over expressions in epithelial hyperplastic lesions of the larynx. Acta Otolaryngol (Stockh) 1997; Suppl ...527: 105-110.
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 Kambi -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 or 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.
