Epithelial hyperplasia of the larynx. A 10-year review of 88 patients

The risk and interval to malignancy of patients with laryngeal dysplasia; a systematic review of case series and meta-analysis

BACKGROUND

Laryngeal dysplasia is a pre-malignant condition with wide variability in rates of malignant transformation reported in the literature. The management and follow-up strategies of these lesions vary widely.

OBJECTIVES

To assess the risk of and interval to malignant transformation in patients with laryngeal dysplasia, the effect of different treatment modalities on malignant transformation and the effects that risk factors such as smoking, excessive alcohol intake and histological grade may have on this.

TYPE OF REVIEW

Systematic of observational studies with attempted meta-analysis.

SEARCH STRATEGY

A structured search of Medline (1966 to January 2010), EMBASE (1980 to January 2010), CINAHL (1981 to January 2010) and Cochrane databases (CENTRAL, Cochrane Library, 1995 to January 2010).

RESULTS

Nine hundred and forty cases from nine studies were included in the analysis. Overall malignant transformation rate was 14% (confidence interval 8, 22) and mean time to malignant transformation was 5.8 years. The malignant transformation rate is higher with increased severity of dysplasia grade - severe/CIS 30.4%versus mild/moderate 10.6% (P < 0.0002). Treatment modality did not show significant effects.

CONCLUSIONS

Laryngeal dysplasia carries a significant risk of malignant transformation. This risk triples with increasing severity of dysplasia. Transformation often occurs late and is not related to the grade of dysplasia. There is little evidence, therefore, to support the early discharge of patients with mild/moderate dysplasia, which is practised by some clinicians.

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.

Epithelial hyperplasia of the larynx a clinical follow-up study

In this retrospective study, the records of 40 patients with epithelial hyperplasia of the larynx, seen between 1980-1991, were reviewed to determine the incidence of malignant transformation during long term follow-up. The mean follow-up time was 58.6 months. The initial pathological diagnoses were hyperkeratosis in one case, parakeratosis in one, dyskeratosis in 12 and dysplasia in 26. During follow up, nine patients developed carcinoma in situ and/or invasive carcinoma. Of these, two patients had been diagnosed with dyskeratosis without dysplastic cells at the initial biopsy. It is therefore important to follow up patients with epithelial hyperplasia of the larynx even when no dysplastic cells are found at the time of diagnosis.

Expression of proliferating cell nuclear antigen in premalignant lesions of the larynx

PURPOSE

This study was performed to 1) evaluate the proliferative activity in premalignancies of the larynx by immunostaining for proliferating cell nuclear antigen (PCNA), 2) to examine the relationship between PCNA expression and histological diagnosis and 3) to evaluate clinical values of PCNA immunostaining.

MATERIALS AND METHODS

The percentage of PCNA-positive nuclei (PCNA index) and their highest location (PCNA grade) were evaluated in 44 specimens of premalignant lesions, 7 premalignant lesions near carcinomas, 9 normal epithelium, and 12 early invasive carcinomas of the larynx. Follow-up was conducted.

RESULTS

The mean of PCNA indices in premalignancies was significantly higher than in normal epithelium but lower than in early invasive carcinomas. PCNA index had no apparent correlation with the histological diagnosis, but in the same case, the higher degree of dysplasia showed higher PCNA index. PCNA grade showed significant correlation with the histological diagnosis. Cases with higher PCNA expression showed higher percentages of recurrence and cancerization. Premalignant lesions near carcinomas presented significantly high PCNA expression.

CONCLUSIONS

The proliferative activity in premalignancies of the larynx is higher than in normal epithelium and lower than in carcinomas. It differs from case to case, but in the same case the higher degree of dysplasia possesses higher proliferative activity. Dysplasia is associated with abnormal proliferation pattern. Special attention should be paid to those with abnormal proliferation patterns as well as high proliferative activity. PCNA immunostaining is of some referential value in predicting clinical outcome and guiding to make an early diagnosis of malignancy.

Grading of precancerous laryngeal lesions by multiparameter image analysis at separate epithelial layers

In order to detect early precancerous changes which do not involve the whole thickness of the epithelium, we used a novel image analysing program based on an IBAS system (Kontron, Germany) to determine nuclear DNA content (NC) as well as average nuclear area (NA) and variation of nuclear area (VA), in the entire epithelium and in three sublayers, parabasal, intermediate, and superficial. DNA aneuploidy was found in only half of the cases classified as 'high-grade' (HG) lesions, comprising carcinoma in situ (CIS) and severe epithelial dysplasias (EDIII), and was chiefly demonstrable in the parabasal third of the epithelium. The other lesions were DNA euploid. HG lesions showed highly significant increases of NA and VA at the lower levels of the epithelium when compared with 'low-grade' (LG) lesions comprising moderate and mild epithelial dysplasias (EDII and EDI). Our data show that the combination of multiparameter image analysis with conventional morphology assists in the objective grading of precancerous lesions and permits the reliable detection of high-grade lesions.

Laser surgery for epithelial hyperplasia of the vocal fold

A total of 88 patients with epithelial hyperplasia of the vocal fold were treated with endolaryngeal microscopic carbon dioxide laser surgery during the period from 1978 to 1990. The majority of the patients were male smokers. During the follow-up period ranging from 12 to 156 months, 15 patients developed recurrence(s). The recurrent lesion was benign epithelial hyperplasia in 8 patients and invasive carcinoma in 7 patients. The recurrences occurred only in preoperative smokers. Discontinuation of smoking following laser surgery did not affect the incidence of recurrence. The incidence of development of carcinoma did not differ between two histologic types: simple hyperplasia without cellular atypia and dysplasia associated with cellular atypia. The incidence of cancer development for dysplasia cases in the present series (6%) was lower than that in previous reports in which the carbon dioxide laser was not employed for the treatment. Postoperative improvement of vocal function was manifested in an increase of the maximum phonation time, a decrease of the mean airflow rate, and an increase in vibratory amplitude and mucosal wave.