Pap smear in the context of Anna Marion Hilliard

Cytopathology (from Greek κύτος, kytos, "a hollow"; πάθος, pathos, "fate, harm"; and -λογία, -logia) is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by George Nicolas Papanicolaou in 1928. Cytopathology is generally used on samples of free cells or tissue fragments, in contrast to histopathology, which studies whole tissues. Cytopathology is frequently, less precisely, called "cytology", which means "the study of cells".

Cytopathology is commonly used to investigate diseases involving a wide range of body sites, often to aid in the diagnosis of cancer but also in the diagnosis of some infectious diseases and other inflammatory conditions. For example, a common application of cytopathology is the Pap smear, a screening tool used to detect precancerous cervical lesions that may lead to cervical cancer.

Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that can invade or spread to other parts of the body. The first sign is most often vaginal bleeding not associated with a menstrual period. Other symptoms include pain with urination, pain during sexual intercourse, or pelvic pain. Endometrial cancer occurs most commonly after menopause.

Approximately 40% of cases are related to obesity. Endometrial cancer is also associated with excessive estrogen exposure, high blood pressure and diabetes. Whereas taking estrogen alone increases the risk of endometrial cancer, taking both estrogen and a progestogen in combination, as in most birth control pills, decreases the risk. Between two and five percent of cases are related to genes inherited from the parents. Endometrial cancer is sometimes called "uterine cancer", although it is distinct from other forms of cancer of the uterus such as cervical cancer, uterine sarcoma, and trophoblastic disease. The most frequent type of endometrial cancer is endometrioid carcinoma, which accounts for more than 80% of cases. Endometrial cancer is commonly diagnosed by endometrial biopsy or by taking samples during a procedure known as dilation and curettage. A pap smear is not typically sufficient to show endometrial cancer. Regular screening in those at normal risk is not called for.

Human papillomavirus-positive oropharyngeal cancer (HPV-positive OPC or HPV+OPC), is a cancer (squamous cell carcinoma) of the throat caused by the human papillomavirus type 16 virus (HPV16). In the past, cancer of the oropharynx (throat) was associated with the use of alcohol or tobacco or both, but the majority of cases are now associated with the HPV virus, acquired by having oral contact with the genitals (oral-genital sex) of a person who has a genital HPV infection. Risk factors include having a large number of sexual partners, a history of oral-genital sex or anal–oral sex, having a female partner with a history of either an abnormal Pap smear or cervical dysplasia, having chronic periodontitis, and, among men, younger age at first intercourse and a history of genital warts. HPV-positive OPC is considered a separate diseasefrom HPV-negative oropharyngeal cancer (also called HPV negative-OPC and HPV-OPC).

HPV-positive OPC presents in one of four ways: as an asymptomatic abnormality in the mouth found by the patient or a health professional such as a dentist; with local symptoms such as pain or infection at the site of the tumor; with difficulties of speech, swallowing, and/or breathing; or as a swelling in the neck if the cancer has spread to local lymph nodes. Detection of a tumour suppressor protein, known as p16, is commonly used to diagnose an HPV-associated OPC. The extent of disease is described in the standard cancer staging system, using the AJCC TNM system, based on the T stage (size and extent of tumor), N stage (extent of involvement of regional lymph nodes) and M stage (whether there is spread of the disease outside the region or not), and combined into an overall stage from I–IV. In 2016, a separate staging system was developed for HPV+OPC, distinct from HPV-OPC.