Pathology 5

• Dysplasia is an abnormal growth and maturation of cells and is a pre-malignant change in cells, usually epithelium, characterized by disordered growth and morphologic changes in the cell nucleus.
• The nuclear changes in dysplasia include crowded and overlapping nuclei, large and irregular nuclei, uneven chromatin distribution and increased mitotic activity.
• Two of the most common examples of dysplasia are squamous dysplasia of the cervix and dysplasia of the respiratory tract.
• Dysplasia is characterized by loss of uniformity of the individual cell, cytological changes in the nucleus and cytoplasm, loss of architectural orientation and maturation of cells, and increased rate of cell multiplication.
• Dysplasia results from genetic alteration (proto-oncogenes) and is promoted by ongoing injury or stimulus which causes increased cell division for repair, such as smoking, reflux oesophagitis, ulcerative colitis.
• On removal of the stimulus, the changes in dysplasia may disappear.
• Dysplasia may occur in pre-existing hyperplasia and metaplasia and in proportion of cases, dysplasia progresses to carcinoma in situ or invasive cancer.
• The morphological features of dysplasia include loss of uniformity of cells, nuclear and cytoplasmic alteration, loss of normal orientation and maturation, and increased rate of multiplication.
• Dysplasia is usually clinically asymptomatic and is diagnosed using special techniques such as fluorescent bronchoscopy to detect bronchial dysplasia and colposcopy for cervical dysplasia.
• Knowing the stage is important in identifying clinical trials that may be suitable for a particular patient.
• Breast cancer is staged using TNM or stage I-IV.
• TNM Staging of Carcinoma is a system used for any tumour but requires some modification.
• Lymphoma is staged using Ann Arbor staging.
• Bladder, lung, kidney, larynx are staged using TNM.
• Ann Arbor Staging for Non Hodgkin Lymphoma is used without modification for breast cancer.
• For solid tumors, TNM (Tumour, node, metastasis) is by far the most commonly used system, but it has been adapted for some conditions.
• Each tumour has a specific staging system.
• Staging helps health care providers and researchers exchange information about patients and gives them a common terminology for evaluating the results of clinical trials and comparing the results of different trials.
• Cervical and ovarian cancer are staged using FIGO staging.
• Astler-Coller/Modified Dukes Staging for Colorectal Cancer is an older, less complicated system.
• Physical examination, imaging studies, laboratory tests, and pathology reports are used to determine stage.
• Duke Staging, Astler-Coller staging (modified Duke) & TNM staging in colorectal cancer are examples of such adaptations.
• Cervical intraepithelial neoplasia (CIN) is a precursor lesion for cervical cancer.
• Neoplasia literally means ‘new growth’, the growth is autonomous, ie independent of growth factors and regulatory mechanisms in cells, and can be classified into benign and malignant.
• Cervical Intraepithelial Neoplasia (CIN) II is a moderate dysplasia that involves 2/3 of the epithelium.
• Neoplasia is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of a normal tissue and persists in the same manner after cessation of the stimuli which evoked the change.
• Cervical Intraepithelial dysplasia (CIN) is a mild dysplasia involving the lower 1/3rd of the epithelial thickness.
• Cervical Intraepithelial Neoplasia (CIN) III or Cervical Intraepithelial Neoplasia (CIS) is a severe dysplasia that involves the full thickness epithelium.
• Adenomatous colonic polyp is a benign glandular tumour projecting into the colonic lumen and has a distinct stalk, lined by dysplastic columnar epithelium.
• In the ovary, there is an entity called borderline tumours.
• Bowen disease is a dysplasia occurring in the genitalia of men and women, and may transform into infiltrating squamous cell carcinoma in approximately 10% of patients.
• The epidermis in Bowen disease shows proliferation with numerous mitoses, some atypical, and the cells are markedly dysplastic with large hyperchromatic nuclei and lack of orderly maturation.
• Ulcerative colitis is an ulcerative inflammatory disease limited to the colon, particularly significant in ulcerative colitis is the spectrum of epithelial changes signifying dysplasia and the progression to frank carcinoma.
• Cervical dysplasia can be classified into Low grade squamous intraepithelial lesion (LGSIL) which includes CIN 1, and High grade squamous intraepithelial lesion (HGSIL) which includes CIN II & III.
• Tissue biopsy is a confirmatory method.
• Flow cytometry is used to detect membrane antigens in leukaemias and lymphomas.
• Immunohistochemistry using specific antibodies to identify the origin of undifferentiated tumour cells such as cytokeratin, vimentin, desmin, factor VIII Ag etc., is a method used in laboratory diagnosis.
• Fine Needle Aspiration Cytology is a method used for palpable lesions such as breast, thyroid, and lymph nodes, as it is less invasive and rapidly performed.
• Cytological studies, also known as PAP smears, are used for the detection of cervical cancers.
• Molecular diagnosis is used to detect gene translocation.