Cervical intraepithelial neoplasia (CIN), also known as cervical dysplasia, is the potentially premalignant transformation and abnormal growth (dysplasia) of squamous cells on the surface of the cervix. Cervical intraepithelial neoplasia most commonly occurs on the cervix at the squamo-columnar junction, but can also occur in vaginal walls and vulvar epthelium. The New Bethesda System reports all gynecologic abnormalities termed "SIL" squamous intraepithelial lesions, arising from all areas of female genital tract, and anal canal of both men and women. Like other intraepithelial neoplasias, CIN or [SIL] is not cancer, and it is usually curable. Most cases of CIN remain stable, or are eliminated by the host's immune system without intervention. However a small percentage of cases progress to become cervical cancer, usually cervical squamous cell carcinoma (SCC), if left untreated. The major cause of CIN is chronic infection of the cervix with the sexually transmitted human papillomavirus (HPV), especially the high-risk HPV types 16 or 18. Over 100 types of HPV have been identified. About a dozen of these types appear to cause cervical dysplasia and may lead to the development of cervical cancer. Other types cause warts.

The earliest microscopic change corresponding to CIN is dysplasia of the epithelial or surface lining of the cervix, which is essentially undetectable by the woman. Cellular changes associated with HPV infection, such as koilocytes, are also commonly seen in CIN. CIN is usually discovered by a screening test, the Papanicolau or "Pap" smear. The purpose of this test is to detect potentially precancerous changes. Pap smear results may be reported using the Bethesda System. An abnormal Pap smear result may lead to a recommendation for colposcopy of the cervix, during which the cervix is examined under magnification. A biopsy is taken of any abnormal appearing areas. Cervical dysplasia can be diagnosed by biopsy. A test for Human Papilloma Virus called the Digene HPV test is highly accurate and serves as both a direct diagnosis and adjuvant to the all important pap test which is a screening device and not the final answer in detecting all types of female genital cancers. Endocervical brush sampling at time of pap smear to detect adenocarcinoma and its precursors is necessary along with doctor/patient vigilance on abdominal symptoms associated with uterine and ovarian carcinoma.

Depending on several factors and the location of the infection, CIN can start in any of the three stage, and can either progress, or regress. The grade of squamous intraepithelial lesion can vary.

CIN is classified in grades:

Intraepithelial neoplasia (IEN) is the development of a benign neoplasia or high-grade dysplasia in an epithelium. The exact dividing line between dysplasia and neoplasia has been very difficult to draw throughout the era of medical science. It varies between persons. In the localizations shown below, the term "intraepithelial neoplasia" is used to describe more accurately what was historically referred to as epithelial dysplasia. IEN is not cancer, but it is associated with higher risk for developing cancer in future. It is thus sometimes a precancerous condition.

HGPIN in isolation is asymptomatic. It is typically discovered in prostate biopsies taken to rule-out prostate cancer and very frequently seen in prostates removed for prostate cancer.

Many malignancies can develop in vulvar structures. The signs and symptoms can include:

- Itching, burn, or bleeding on the vulva that does not go away.

- Changes in the color of the skin of the vulva, so that it looks redder or whiter than is normal.

- Skin changes in the vulva, including what looks like a rash or warts.

- Sores, lumps, or ulcers on the vulva that do not go away.

- Pain in the pelvis, especially during urination or sex.

Typically, a lesion presents in the form of a lump or ulcer on the labia majora and may be associated with itching, irritation, local bleeding or discharge, in addition to pain with urination or pain during sexual intercourse. The labia minora, clitoris, perineum and mons are less commonly involved. Due to modesty or embarrassment, patients may put off seeing a doctor.

Melanomas tend to display the typical asymmetry, uneven borders and dark discoloration as do melanomas in other parts of the body.

Adenocarcinoma can arise from the Bartholin gland and present with a painful lump.

On a subsequent biopsy, given a history of a HGPIN diagnosis, the chance of finding prostatic adenocarcinoma is approximately 30%.

A squamous intraepithelial lesion (SIL) is an abnormal growth of epithelial cells on the surface of the cervix, commonly called squamous cells. This condition can lead to cervical cancer, but can be diagnosed using a Pap smear or a colposcopy. It can be treated by using methods that remove the abnormal cells, allowing normal cells to grow in their place. In the Bethesda system, the cytology can be graded as LSIL (low-grade squamous intraepithelial lesion) or HSIL (high-grade squamous intraepithelial lesion).

Anal dysplasia is a pre-cancerous condition which occurs when the lining of the anal canal undergoes abnormal changes. It can be classified as low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL).

Most cases are not associated with symptoms, but people may notice lumps in and around the anus.

Vaginal intraepithelial neoplasia (VAIN) is a condition that describes premalignant histological findings in the vagina characterized by dysplastic changes.

The disorder is rare and generally has no symptoms. VAIN can be detected by the presence of abnormal cells in a Papanicolaou test (Pap smear).

Like cervical intraepithelial neoplasia, VAIN comes in three stages, VAIN 1, 2, and 3. In VAIN 1, a third of the thickness of the cells in the vaginal skin are abnormal, while in VAIN 3, the full thickness is affected. VAIN 3 is also known as carcinoma in-situ, or stage 0 vaginal cancer.

Infection with certain types of the human papillomavirus ("high-risk types") may be associated with up to 80% of cases of VAIN. Vaccinating girls with HPV vaccine before initial sexual contact has been shown to reduce incidence of VAIN.

One study found that most cases of VAIN were located in the upper third of the vagina, and were multifocal. In the same study, 65 and 10% patients with VAIN also had cervical intraepithelial neoplasia and vulvar intraepithelial neoplasia, respectively.

In another study, most cases of VAIN went into remission after a single treatment, but about 5% of the cases studied progressed into a more serious condition despite treatment.

Vulvar cancer is a malignant, invasive growth in the vulva, or the outer portion of the female genitals. The disease accounts for only 0.6% of cancer diagnoses but 5% of gynecologic cancers in the United States. The labia majora are the most common site involved representing about 50% of all cases, followed by the labia minora. The clitoris and Bartholin glands may rarely be involved.

Vulvar cancer is separate from vulvar intraepithelial neoplasia (VIN), a superficial lesion of the epithelium that has not invaded the basement membrane—or a pre-cancer. VIN may progress to carcinoma-in-situ and, eventually, squamous cell cancer.

According to the American Cancer Society, in 2014, there were about 4,850 new cases of vulvar cancer and 1,030 deaths from the disease. In the United States, five-year survival rates for vulvar cancer are around 70%.

Symptoms of anal cancer can include pain or pressure in the anus or rectum, a change in bowel habits, a lump near the anus, rectal bleeding, itching or discharge. Bleeding may be severe.

The early stages of cervical cancer may be completely free of symptoms. Vaginal bleeding, contact bleeding (one most common form being bleeding after sexual intercourse), or (rarely) a vaginal mass may indicate the presence of malignancy. Also, moderate pain during sexual intercourse and vaginal discharge are symptoms of cervical cancer. In advanced disease, metastases may be present in the abdomen, lungs, or elsewhere.

Symptoms of advanced cervical cancer may include: loss of appetite, weight loss, fatigue, pelvic pain, back pain, leg pain, swollen legs, heavy vaginal bleeding, bone fractures, and (rarely) leakage of urine or feces from the vagina. Bleeding after douching or after a pelvic exam is a common symptom of cervical cancer.

EIN lesions have been discovered by a combination of molecular, histologic, and clinical outcome studies beginning in the 1990s which provide a multifaceted characterization of this disease. They are a subset of a larger mixed group of lesions previously called "endometrial hyperplasia". The EIN diagnostic schema is intended to replace the previous "endometrial hyperplasia" classification as defined by the World Health Organization in 1994, which have been separated into benign (benign endometrial hyperplasia) and premalignant (EIN) classes in accordance with their behavior and clinical management.

EIN should not be confused with an unrelated entity, serous intraepithelial carcinoma ("serous EIC"), which is an early stage of a different tumor type known as papillary serous adenocarcinoma that also occurs in the same location within the uterus.

Endometrial intraepithelial neoplasia (EIN) is a premalignant lesion of the uterine lining that predisposes to endometrioid endometrial adenocarcinoma. It is composed of a collection of abnormal endometrial cells, arising from the glands that line the uterus, which have a tendency over time to progress to the most common form of uterine cancer—endometrial adenocarcinoma, endometrioid type.

The term Vulvar intraepithelial neoplasia (VIN) refers to particular changes that can occur in the skin that covers the vulva. VIN is not cancer, and in some women it disappears without treatment. If the changes become more severe, there is a chance that cancer might develop after many years, and so it is referred to as a precancerous condition.

Medically speaking, the term denotes a squamous intraepithelial lesion of the vulva that shows dysplasia with varying degrees of atypia. The epithelial basement membrane is intact and the lesion is thus not invasive but has invasive potential.

The terminology of VIN evolved over several decades. In 1989 the Committee on Terminology, International Society for the Study of Vulvar Disease (ISSVD) replaced older terminology such as vulvar , Bowen's disease, and Kraurosis vulvae by a new classification system for "Epithelial Vulvar Disease":

- Nonneoplastic epithelial disorders of vulva and mucosa:

- Lichen sclerosus

- Squamous hyperplasia

- Other dermatoses

- Mixed neoplastic and nonneoplastic disorders

- Intraepithelial neoplasia

- Squamous vulvar intraepithelial neoplasia (VIN)

- VIN I, mildest form

- VIN II, intermediate

- VIN III, most severe form including carcinoma in situ of the vulva

- Non-squamous intraepithelial neoplasia

- Extramammary Paget's disease

- Tumors of melanocytes, noninvasive

- Invasive disease (vulvar carcinoma)

The ISSVD further revised this classification in 2004, replacing the three-grade system with a single-grade system in which only the high-grade disease is classified as VIN.

VIN is subdivided into: (Robbins Pathological Basis of Disease, 9th Ed)

Classic vulvular intraepithelial neoplasia: associated with developing into the warty and basaloid type carcinoma. This is associated with carcinogenic genotypes of HPV and/or HPV persistence factors such as cigarette smoking or immunocompromised states.

Differentiated vulvar intraepithelial neoplasia also known as VIN Simplex: is associated with vulvar dermatoses such as lichen sclerosus. It is associated with atypia of the squamous epithelium.

Gastrointestinal intraepithelial neoplasia (GIN or GIIN), also known as "digestive epithelial dysplasia" is abnormal growth (cellular dysplasia) of digestive epithelial cells in the digestive mucosa.

Gastrointestinal intraepithelial neoplasia is the potentially premalignant transformation.

Since 2000, they are classified according to the Vienna classification.

Penile cancer arises from precursor lesions, which generally progress from low-grade to high-grade lesions. For HPV related penile cancers this sequence is as follows:

- A. Squamous hyperplasia;

- B. Low-grade penile intraepithelial neoplasia (PIN);

- C. High-grade PIN (carcinoma in situ—Bowen's disease, Erythroplasia of Queyrat and bowenoid papulosis (BP));

- D. Invasive Carcinoma of the Penis.

However, in some cases non-dysplastic or mildly dysplastic lesions may progress directly into cancer. Examples include flat penile lesions (FPL) and condylomata acuminata.

In HPV negative cancers the most common precursor lesion is lichen sclerosus (LS).

A precancerous condition or premalignant condition, sometimes called a potentially precancerous condition or potentially premalignant condition, is a state of disordered morphology of cells that is associated with an increased risk of cancer. If left untreated, these conditions may lead to cancer. Such conditions are usually either dysplasia or benign neoplasia (and the dividing line between those is sometimes blurry). Sometimes the term "precancer" is used to describe carcinoma in situ, which is a noninvasive cancer that has not progressed to an aggressive, invasive stage. Not all carcinoma in situ will progress to invasive disease.

Premalignant lesions are morphologically atypical tissue which appears abnormal under microscopic examination, and in which cancer is more likely to occur than in its apparently normal counterpart.

Examples of premalignant conditions include:

- actinic keratosis

- Barrett's esophagus

- atrophic gastritis

- ductal carcinoma in situ

- dyskeratosis congenita

- sideropenic dysphagia

- lichen planus

- oral submucous fibrosis

- solar elastosis

- cervical dysplasia

- leukoplakia

- erythroplakia

The term was coined in 1875 by Romanian physician Victor Babeş.

On a subsequent biopsy, given the diagnosis of ASAP, the chance of finding prostate adenocarcinoma is approximately 40%; this is higher than if there is high-grade prostatic intraepithelial neoplasia (HGPIN).

Like many malignancies, penile cancer can spread to other parts of the body. It is usually a primary malignancy, the initial place from which a cancer spreads in the body. Much less often it is a secondary malignancy, one in which the cancer has spread to the penis from elsewhere. The staging of penile cancer is determined by the extent of tumor invasion, nodal metastasis, and distant metastasis.

The T portion of the AJCC TNM staging guidelines are for the primary tumor as follows:

- TX: Primary tumor cannot be assessed.

- T0: No evidence of primary tumor.

- Tis: Carcinoma "in situ".

- Ta: Noninvasive verrucous carcinoma.

- T1a: Tumor invades subepithelial connective tissue without lymph vascular invasion and is not poorly differentiated (i.e., grade 3–4).

- T1b: Tumor invades subepithelial connective tissue with lymph vascular invasion or is poorly differentiated.

- T2: Tumor invades the corpus spongiosum or cavernosum.

- T3: Tumor invades the urethra or prostate.

- T4: Tumor invades other adjacent structures.

Anatomic Stage or Prognostic Groups of penile cancer are as follows:

- Stage 0—Carcinoma "in situ".

- Stage I—The cancer is moderately or well differentiated and only affects the subepithelial connective tissue.

- Stage II—The cancer is poorly differentiated, affects lymphatics, or invades the corpora or urethra.

- Stage IIIa—There is deep invasion into the penis and metastasis in one lymph node.

- Stage IIIb—There is deep invasion into the penis and metastasis into multiple inguinal lymph nodes.

- Stage IV—The cancer has invaded into structures adjacent to the penis, metastasized to pelvic nodes, or distant metastasis is present.

Cervical polyps often show no symptoms. Where there are symptoms, they include intermenstrual bleeding, abnormally heavy menstrual bleeding (menorrhagia), vaginal bleeding in post-menopausal women, bleeding after sex and thick white vaginal or yellowish discharge (leukorrhoea).

Cervical ectropion can be associated with excessive but non-purulent vaginal discharge due to the increased surface area of columnar epithelium containing mucus-secreting glands. It may also give rise to post-coital bleeding, as fine blood vessels present within the columnar epithelium are easily traumatised.

Anal dysplasia is most commonly linked to human papillomavirus (HPV), a usually sexually-transmitted infection. HPV is the most common sexually transmitted infection in the United States while genital herpes (HSV) was the most common sexually transmitted infection globally.

Anal cancer is a cancer (malignant tumor) which arises from the anus, the distal opening of the gastrointestinal tract. It is a distinct entity from the more common colorectal cancer.

Anal cancer is typically an anal squamous cell carcinoma that arises near the squamocolumnar junction, often linked to human papillomavirus (HPV) infection. It may be keratinizing (basaloid) or non-keratinizing (cloacogenic). Other types of anal cancer are adenocarcinoma, lymphoma, sarcoma or melanoma. From data collected 2004-2010, the relative five year survival rate in the United States is 65.5%, though individual rates may vary depending upon the stage of cancer at diagnosis and the response to treatment.