Koilocyte

Koilocyte is a type of epithelial cell that has undergone structural changes as a result of infection by the Human Papillomavirus (HPV). The term "koilocyte" is derived from the Greek words "koilos," meaning hollow, and "kytos," meaning cell. These cells are characterized by a perinuclear halo and an irregular, enlarged nucleus.

Characteristics

Koilocytes are typically found in the stratified squamous epithelium, which is the type of tissue that lines the body's cavities and covers its surfaces. They are most commonly associated with HPV infections, particularly those caused by high-risk HPV types such as HPV 16 and 18, which are known to cause cervical cancer.

The most distinctive feature of a koilocyte is the perinuclear halo, a clear area surrounding the cell's nucleus. This is caused by the accumulation of viral particles within the cell, which pushes the cell's cytoplasm outward. The nucleus of a koilocyte is often irregular and enlarged, and may contain multiple nucleoli.

Clinical Significance

The presence of koilocytes in a tissue sample is a key diagnostic indicator of an HPV infection. They are often identified during a Pap smear, a screening test for cervical cancer. However, not all HPV infections result in the formation of koilocytes, and their absence does not rule out the possibility of an infection.

HPV infections are a major risk factor for the development of cervical cancer, and the presence of koilocytes may indicate a high-risk infection. However, most HPV infections, even those caused by high-risk types, do not lead to cancer. The risk of cancer development is influenced by a variety of factors, including the individual's immune response and the presence of other risk factors such as smoking.

See Also

• Human papillomavirus
• Cervical cancer
• Pap smear
• Epithelial cell

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