5.1 A ‘successful’ HPV infection depends upon virus particles making contact with basal epithelial cells or reserve cells. Can you think of possible ways in which the virus can penetrate the protective stratified squamous epithelium in the cervix?
Tiny abrasions in the cervical epithelium are the supposed access routes for the virus. Other possibilities include entry via the SCJ and in areas of reserve cell hyperplasia.
5.2 What is the difference between neoplasia and hyperplasia?
Neoplasia is an abnormal growth of new tissue, whereas hyperplasia is a normal increase in the number of cells in a tissue.
5.3 Explain the terms ‘undifferentiated’, ‘cytoplasmic differentiation’, and ‘keratinization’. Hint: look back at Chapter 4.
Undiff erentiated cells completely lack morphological and functional specialization and have an ill-defi ned morphology. Cytoplasmic diff erentiation refers to the morphological and functional specialization that cells undergo as they mature. Keratinization is the accumulation of the tough protein keratin in cells and tissues in response to injury or infection.
5.4 What are the main distinguishing features of CIN1, CIN2, and CIN3? Draw simple diagrams to illustrate your answer.
CIN1 is characterized by undiff erentiated neoplastic cells occupying the lower one-third of the epithelium. Cytoplasmic diff erentiation is seen in the middle and upper thirds. Mitotic fi gures are infrequent and usually normal. In CIN2, undiff erentiated neoplastic cells reach the middle third of the epithelium and cytoplasmic diff erentiation is seen in the upper third. Mitoses are confi ned to the lower two-thirds and these may be abnormal in appearance. The features of CIN3 are more exaggerated. The full thickness of the epithelium is occupied by undiff erentiated neoplastic cells without signs of cytoplasmic diff erentiation. Occasionally, cases with cell keratinization are found. Mitoses are frequently seen throughout the epithelium and are often abnormal.
5.5 What are the main distinguishing features of low-grade and high-grade dyskaryosis? Draw simple diagrams to illustrate your answer.
Mild dyskaryosis: NCR0.67, uneven chromatin more striking than in moderate dyskaryosis, often seen in dense cell clusters (‘hyperchromatic crowded cell groups’).
5.6 Look back at Figure 4.8 in Chapter 4. In the same style draw a diagram to represent the chromatin pattern and distribution of a dyskaryotic nucleus, using Figure 5.5 as a guide. This small exercise will encourage you to examine chromatin in detail when interpreting cell nuclei.
Chromatin is coarsened and irregularly distributed.
5.7 Summarize the cytological and histological features of invasive squamous cell carcinoma.
Cytological features: numerous dyskaryotic cells, cellular pleomorphism, very coarse aggregates of chromatin, large irregular and multiple nucleoli, cytoplasmic keratinization, tissue fragments (microbiopsies), tumour diathesis Histological features: evidence that malignant cells have breached the basement membrane; islands of pleomorphic tumour cells with intercellular bridges; epithelial pearls, and keratinization (depending on the degree of diff erentiation).
5.8 Describe the main distinguishing features of squamous and endocervical dyskaryosis.
Squamous dyskaryosis Endocervical dyskaryosis Features of individual cells most important. Cell groups tend to be disorganized, with loss of nuclear polarity. Edges of cell groups are either flat or ragged. Tendency toward nuclear and cellular pleomorphism. Densely coarse chromatin. Irregular nuclear outline. Different grades according to nucleocytoplasmic ratio. Multinucleation common. Densely stained cytoplasm. Evidence of cytoplasmic keratinization may be present (orangeophilia). Architectural features of cell groups most important. Cell groups tend to be organized into pseudostratified strips and rosettes, with maintenance of polarity. Edges of cell groups tend to be feathered or frayed. Little or no pleomorphism. Chromatin may be coarse or finely granular. Nuclei are often oval in shape with smooth nuclear membranes. There is no system of grading endocervical dyskaryosis. Multinucleation rare. Delicate pale-stained cytoplasm. No keratinisation.
5.9 Suggest a few practical steps that could be taken to minimize the occurrence of false negative and false positive reporting in a cytology laboratory.
Well-trained staff , good quality preparations (see Chapter 2), ergonomic microscope workstation, controlled environment (heating, lighting, humidity, temperature, noise levels, etc.), regular breaks from microscopy, eff ective quality control mechanisms (see Chapter 6).
5.10 Briefly outline the procedures conducted during a colposcopic examination.
Initial naked-eye inspection of the external genitalia and cervix. A colposcope is used to examine the cervical epithelium and the patterns of blood vessels. The application of acetic acid helps in the identifi cation of abnormal areas. Lugol’s iodine helps to identify the transformation zone and to further resolve any suspicious areas by staining normal tissue a deep brown, whilst leaving neoplastic epithelium unstained. A punch biopsy may be taken from any suspicious areas for histological confi rmation. Treatment such as LLETZ or cone excision may also be performed under colposcopic guidance. Establishing haemostasis is the fi nal step of the procedure.
5.11 Can you list the main approaches to treating biopsy-proven CIN and CGIN? How do these methods differ from the treatment of invasive cancer?
Treatment of CIN: laser, cold coagulation, cryotherapy, (LLETZ), and cone excision. Treatment of CGIN is by excision techniques only, e.g. cone excision. Treatment of invasive cancer is stage dependent and may involve hysterectomy, chemotherapy, radiotherapy, or a combination of these.