الفهرس 
Preneoplastic Lesions of the LarynxOnly 14 pages are availabe for public view
 |  | from | 34 |  |  |
| | | from | 34 | | |
Abstract
PCNA is a nuclear protein associated with the cell cycle, it is present in the nuclei
of proliferating cells and ab_sent in resting cells. It has been widely studied as a
marker to evaluate proliferative activity. in malignant lesions as well as
premalignanci~s.
This work aims at evaluation of proliferative activity in premalignant as well as
malignant lesions of the larynx by the mean of imrnunohistolochemical study for
proliferating cell nuclear antigen.
A total number of 50 samples of laryngeal lesion, benign and malignant were
selected to represent nom1al laryngeal epithelium in cases of benign L. nodules
(n= 10). Dysplastic laryngeal lesions (n= 12) and invasive squamous cell carcinoma
(n=28).
Each specimen was then examined for PCNA reactivity whether positive or
negative. In all positive cases PCNA index was evaluated. PCNA grade was
evaluated only in dysplastic cases. This study revealed that PCNA was expressed in
83.3% of laryngeal dysplastic cases. According to the severity of dysplasia the
distribution of PCNA immunoreactivity was as follows: Mild dysplasia 75%,
moderate dysplasia 100% and severe dysplasia 100%.
PCNA expression in cases of squamous cell carcinoma of the larynx was 85.7%.
According to the grade of squamous cell carcinoma the distribution of PCNA
positive immunoreactivity was as follows: Grade I 80%, Grade II 85. 7% and Grade
III 100%.
PCNA expression in cases of benign nodules was limited to the basal and parabasal
layers, which was considered nonnal findings.
It was concluded from this study that proliferative activity in dysplastic laryngeal
lesions was higher than in normal epithelium but not reached that of laryngeal
squamous cell carcinoma.
PCNA grade was conelated with the histopathological diagnosis in cases of
laryngeal dysplasia. PCNA index had no constant correlation with the
histopathological diagnosis in cases of laryngeal dysplasia. PCNA index had
positive con-elation with the histological diagnosis in cases of S.C.C.
The proliferative activity in premalignancies of the larynx is higher than in normal
epithelium and lower than in carcinomas.