BRIEF RESUME OF THE INTENDED WORK:
6.1 Need for the study:
Nucleolar organizer regions (NORs) are chromosomal segments encoding for ribosomal ribonucleic acid, located on five acrocentric chromosomes numerically 13,14,15,21 and 22.These nucleolar regions are associated with acidic nonhistone proteins which are argyrophilic.1
NORs can be rapidly identified in light microscopic sections by a simple, one-step, colloidal silver technique. The NORs thus stained are called AgNORs and appear as black dots within the nucleus.2
The study of AgNORs has enjoyed a vogue in diagnostic tumour pathology as increased number of AgNORs correlates with increased cellular proliferation3. Recently much attention has been paid to demonstration of nucleolar organizer regions (NORs) because of the fact that their frequency within nuclei is significantly higher in neoplasms with high biological activity.4
Counts of AgNORs have been of use in distinguishing benign from malignant, as their frequency is significantly higher in malignant cells than in normal, reactive or benign cells.5 The specificity and simplicity of the AgNOR staining procedure has led to widespread application of this technique in human pathology.1.
Endometrium is an important target for hormonal stimulation and affected by a variety of disease processes including endometritis, hyperplasias and carcinomas.
So, the present study is undertaken to substantiate the histopathological diagnosis of various nonneoplastic and neoplastic lesions of endometrium by AgNOR staining and also to observe the sensitivity of this technique in differentiating between these lesions.
6.2 Review of literature:
AgNOR staining has already been applied and shown to be of great value in differentiating benign from malignant in lesions of breast, cervix and oral cavity, skin and soft tissue tumours, lymphomas and melanomas.6-11
Niwa et al conducted a study on 23 specimens with known endometrial pathology and 21 normal specimens. AgNORs were counted in hyperplastic and neoplastic endometrium and compared with normal endometrium. The mean number of AgNORs in proliferative phase of endometrium was significantly higher (3.8) than that in secretory phase (2.7).
The mean number of AgNORs in well-differentiated endometrioid type adenocarcinoma was significantly higher (5.5) than that in both complex hyperplasia without cytological atypia (3.6) & simple hyperplasia (3.3).Their findings suggested that the mean numbers of AgNORs are increased in neoplastic changes in endometrium.12
Brustmann et al applied this method to 78 sections of endometrial tissues obtained either from curettage or from hysterectomy specimens. Mean AgNOR counts per cell were 3.2 in normal proliferative, 2.7 in normal secretory endometrium and increased to 4.1 in simple hyperplasia to 5.4 in complex hyperplasia to 8.1 in atypical hyperplasia finally to 10.0 in endometrial carcinoma. They concluded that AgNOR counts are reliable markers of endometrial proliferation and allow a clear distinction between benign, premalignant and malignant epithelial changes.13
Kaushik et al conducted AgNOR staining on 100 endometrial specimens, 15 being normal controls (proliferative and secretory endometrium) and 85 lesions comprising of endometritis (15), hyperplasia (25) and carcinoma (45). On being subjected to AgNOR staining, scores increased steadily from normal to endometritis to endometrial hyperplasia and carcinoma. Statistically significant difference was seen in scores between atypical hyperplasia and carcinomas. They concluded that AgNOR staining is a simple, inexpensive and useful adjunct to routine histopathology to evaluate endometrial lesions especially to differentiate borderline lesions.5
Terlikowski et al conducted a similar study on 87 endometrial specimens with simple & complex hyperplasia with or without atypia and well differentiated stage-1 endometrial adenocarcinoma. They concluded that proliferative activity of cells expressed by AgNOR count can help in distinction between atypical hyperplasia and well differentiated adenocarcinoma and thus can serve as a useful pathological criterion.14
6.3 Objectives of the study:
1) To study the efficacy of AgNOR technique in differentiating between nonneoplastic and neoplastic lesions of endometrium.
2) To assess the relationship between AgNOR counts and severity of hyperplasia and carcinoma. .
MATERIALS AND METHODS
7.1 Source of data:
Endometrial specimens obtained by hysterectomy and dilatation & curettage ( D&C) received in the Department of Pathology, K.V.G.Medical College and Hospital, Sullia (D.K) for histopathological examination.
Study period is July 2009 to August 2011.
Sample size : Intended to study 100 cases.
7.2 Method of collection of data
All endometrial specimens obtained by hysterectomy and dilatation & curettage ( D&C)
sent for histopathological examination to the Department of Pathology, K.V.G.Medical College and Hospital, Sullia are routinely processed. Two paraffin sections are cut from each paraffin block. One section is stained with hematoxylin and eosin (H & E), other section is subjected to AgNOR staining. Statistical tests are applied to get the average AgNOR count for each histological lesion.
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