A benign papillomatous tumor is derived from epithelium, with cauliflower-like projections that arise from the mucosal surface.

It may appear white or normal colored. It may be pedunculated or sessile. The average size is between 1–5 cm.

Neither sex is significantly more likely to develop them. The most common site is the palate-uvula area followed by tongue and lips. Durations range from weeks to 10 years.

Squamous cell papilloma of the mouth or throat is generally diagnosed in people between the ages of 30 and 50, and is normally found on the inside of the cheek, on the tongue, or inside of lips. Oral papillomas are usually painless, and not treated unless they interfere with eating or are causing pain. They do not generally mutate to cancerous growths, nor do they normally grow or spread. Oral papillomas are most usually a result of the infection with types HPV-6 and HPV-11.

A squamous cell papilloma is a generally benign papilloma that arises from the stratified squamous epithelium of the skin, lip, oral cavity, tongue, pharynx, larynx, esophagus, cervix, vagina or anal canal. Squamous cell papillomas are a result of infection with human papillomavirus (HPV).

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.

The patient may have no symptoms, or local symptomatology including itching, burning, and pain.

The diagnosis is always based on a careful inspection and a targeted biopsy of a visible vulvar lesion.

The type and distribution of lesions varies among the two different types of VIN. In the Usual type VIN, seen more frequently in young patients, lesions tend to be multifocal over an otherwise normal vulvar skin. In the differentiated type VIN, usually seen in postmenopausal women, lesions tend to be isolated and are located over a skin with a vulvar dermatosis such as Lichen slerosus.

Cancer can be considered a very large and exceptionally heterogeneous family of malignant diseases, with squamous cell carcinomas comprising one of the largest subsets.

Conjunctival Squamous Cell Carcinoma (Conjunctival SCC) and corneal intraepithelial neoplasia comprise what are called Ocular Surface Squamous Cell Neoplasias. SCC is the most common malignancy of the conjunctiva in the US, with a yearly incidence of 1-2.8 per 100,000. Risk factors for the disease are exposure to sun (specifically occupational), exposure to UVB, and light-colored skin. Other risk factors include radiation, smoking, HPV, arsenic, and exposure to polycyclic hydrocarbons.

Conjunctival SCC is often asymptomatic at first, but it can present with the presence of a growth, red eye, pain, itching, burning, tearing, sensitivity to light, double vision, and decreased vision.

Spread of conjunctival SCC can occur in 1-21% of cases, with the first site of spread being the regional lymph nodes. Mortality for conjunctival SCC ranges from 0-8%.

Diagnosis is often made by biopsy, as well as CT (in the case of invasive SCC).

Treatment of Conjunctival SCC is usually surgical excision followed by cryotherapy. After this procedure, Conjunctival SCC can recur 8-40% of the time. Radiation treatment, topical Mitomycin C, and removal of the contents of the orbit, or exenteration, are other methods of treatment. Close follow-up is recommended, because the average time to recurrence is 8–22 months.

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).

Note: differentiation is done accurately by microscopic examination only.

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.

Keratoacanthomas (molluscum sebaceum) may be divided into the following types:

- "Giant keratoacanthomas" are a variant of keratoacanthoma, which may reach dimensions of several centimeters.

- "Keratoacanthoma centrifugum marginatum" is a cutaneous condition, a variant of keratoacanthomas, which is characterized by multiple tumors growing in a localized area.

- "Multiple keratoacanthomas" (also known as "Ferguson–Smith syndrome," "Ferguson-Smith type of multiple self-healing keratoacanthomas,") is a cutaneous condition, a variant of keratoacanthomas, which is characterized by the appearance of multiple, sometimes hundreds of keratoacanthomas.

- A "solitary keratoacanthoma" (also known as "Subungual keratoacanthoma") is a benign, but rapidly growing, locally aggressive tumor which sometimes occur in the nail apparatus.

- "Generalized eruptive keratoacanthoma" (also known as "Generalized eruptive keratoacanthoma of Grzybowski") is a cutaneous condition, a variant of keratoacanthomas, characterized by hundreds to thousands of tiny follicular keratotic papules over the entire body. Treatments are not successful for many patients with Generalized eruptive keratoacanthoma. Use of emollients and anti-itch medications can ease some symptoms. Improvement or complete resolutions of the condition has occurred with the application of the following medications: Acitretin, Isotretinoin, Fluorouracil, Methotrexate, Cyclophosphamide.

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.

The early lesions are usually asymptomatic. The patients presenting with an advanced stage of the disease comprises around 66-77% of the cases.

The most important signs include a lump in the neck when palpated and weight loss.

People may also present with fatigue as a symptom.

The primary tumor does not have readily discernible signs or symptoms as they grow within the tonsillar capsule. It is difficult to notice anything suspicious on examination of the tonsil other than slight enlargement or the development of firmness around the area.

The carcinoma may occur in one or more sites deep within the tonsillar crypts. It may be accompanied by the enlargement of the tonsil. The affected tonsil grows into the oropharyngeal space making it noticeable by the patient in the form of a neck mass mostly in the jugulodiagastric region.

As the tonsils consist of a rich network of lymphatics, the carcinoma may metastasise to the neck lymph nodes which many are cystic.

Extension of tumor to skull or mediastinum can occur.

The additional symptoms include a painful throat, dysphagia, otalgia (due to cranial nerve involvement), foreign body sensation, bleeding, fixation of tongue (infiltration of deep muscles) and trismus (if the pterygoid muscle is involved in the parapharyngeal space).

On the other hand, the tumor may also present as a deep red or white fungating wound growing outwards, breaking the skin surface with a central ulceration. This wound-like ulcer fails to heal (non-healing) leading to bleeding and throat pain and other associated symptoms.

During biopsy, the lesion may show three signs: Gritty texture, Firmness and cystification owing to keratinization, fribrosis and necrosis respectively.

Cervical lymphydenopathy may be present.

Although often the terms "erythroplasia" and "erythroplakia" are used synonymously, some sources distinguish them, stating that the latter is maccular (flat) while the former is papular (bumpy).

Erythroplakia of the genital mucosae is often referred to as erythroplasia of Queyrat.

The most common areas in the mouth where erythroplakia is found are the floor of the mouth, buccal vestibule, the tongue, and the soft palate. It appears as a red macule or plaque with well-demarcated borders. The texture is characterized as soft and velvety. An adjacent area of leukoplakia may be found along with the erythroplakia.

Erythroplasia may also occur on the laryngeal mucosa, or the anal mucosa.

Keratoacanthoma (KA) is a common low-grade (unlikely to metastasize or invade) skin tumour that is believed to originate from the neck of the hair follicle.

The defining characteristic of KA is that it is dome-shaped, symmetrical, surrounded by a smooth wall of inflamed skin, and capped with keratin scales and debris. It grows rapidly, reaching a large size within days or weeks, and if untreated for months will almost always starve itself of nourishment, necrose (die), slough, and heal with scarring. KA is commonly found on sun-exposed skin, often face, forearms and hands.

Under the microscope, keratoacanthoma very closely resembles squamous cell carcinoma. In order to differentiate between the two, almost the entire structure needs to be removed and examined. While some pathologists classify KA as a distinct entity and not a malignancy, about 6% of clinical and histological keratoacanthomas do progress to invasive and aggressive squamous cell cancers; some pathologists may label KA as "well-differentiated squamous cell carcinoma, keratoacanthoma variant", and prompt definitive surgery may be recommended.

Vaginal squamous cell carcinoma spreads slowly and usually stays near the vagina, but may spread to the lungs and liver. This is the most common type of vaginal cancer.

Warty dyskeratoma must be differentiated from vulvar dysplasia, Bowenoid papulosis, squamous carcinoma, condyloma, and other viral-induced squamous lesions.

Most bladder cancer is transitional cell, but bladder cancer associated with Schistosomiasis is often squamous cell 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:

Bowen's disease typically presents as a gradually enlarging, well-demarcated red colored plaque with an irregular border and surface crusting or scaling. Bowen's disease may occur at any age in adults, but is rare before the age of 30 years; most patients are aged over 60. Any site may be affected, although involvement of palms or soles is uncommon. Bowen's disease occurs predominantly in women (70–85% of cases). About 60–85% of patients have lesions on the lower leg, usually in previously or presently sun-exposed areas of skin.

This is a persistent, progressive, unelevated, red, scaly or crusted plaque which is due to an intraepidermal carcinoma and is potentially malignant. The lesions may occur anywhere on the skin surface, including on mucosal surfaces. Freezing, cauterization, or diathermy coagulation is often effective treatment. Pathomorphologic study of tissue sampling revealed: polymorphism of spiny epithelial cells has progressed into atypism; increased mitosis; giant and multinucleate cells; acanthosis; hyperkeratosis and parakeratosis; basal membrane and basal layer are retained.

In the context of lesions of the mucous membrane lining of the bladder, leukoplakia is a historic term used to describe a visualized white patch which histologically represents keratinization in an area of squamous metaplasia. The symptoms may include frequency, suprapubic pain (pain felt above the pubis), hematuria (blood in the urine), dysuria (difficult urination or pain during urination), urgency, and urge incontinence. The white lesion may be seen during cystoscopy, where it appears as a whitish-gray or yellow lesion, on a background of inflamed urothelium and there may be floating debris in the bladder. Leukoplakia of the bladder may undergo cancerous changes, so biopsy and long term follow up are usually indicated.

Basal cell carcinoma makes up about 1–2% of vulvar cancer. These tend to be slow-growing lesions on the labia majora but can occur anywhere on the vulva. Their behavior is similar to basal cell cancers in other locations. They often grow locally and have low risk for deep invasion or metastasis.

Treatment involves excision, but these lesions have a tendency to recur if not completely removed.

Most cases of leukoplakia cause no symptoms, but infrequently there may be discomfort or pain. The exact appearance of the lesion is variable. Leukoplakia may be white, whitish yellow or grey. The size can range from a small area to much larger lesions. The most common sites affected are the buccal mucosa, the labial mucosa and the alveolar mucosa, although any mucosal surface in the mouth may be involved. The clinical appearance, including the surface texture and color, may be homogenous or non-homogenous (see: classification). Some signs are generally associated with a higher risk of cancerous changes (see: prognosis).

Leukoplakia may rarely be associated with esophageal carcinoma.

Bowenoid papulosis is a cutaneous condition characterized by the presence of pigmented verrucous papules on the body of the penis. They are associated with human papillomavirus, the causative agent of genital warts. The lesions have a typical dysplastic histology and are generally considered benign, although a small percentage will develop malignant characteristics.

It is considered as a pre-malignant condition. Other terms used to describe the condition are: Erythroplasia of Queyrat, Squamous cell carcinoma in situ and Bowen’s disease. The term "Bowenoid papulosis" was coined in 1977 by Kopf and Bart and is named after dermatologist John Templeton Bowen.

The term “intraepithelial neoplasia” defines a premalignant intraepithelial change.

On the vulva it is termed VIN (vulvar or vulval intraepithelial neoplasia); on the penis, PIN (penile intraepithelial neoplasia); and on or around the anus, AIN (anal intraepithelial neoplasia). The terminology has been very confusing and it is now recommended that the terms Bowen’s disease, erythroplasia of Queyrat, and bowenoid papulosis should not be used for lesions in the anogenital area. However, dermatologists still recognize a distinct clinical variant, bowenoid papulosis, characterized by discrete papules in a younger age group and a tendency for spontaneous regression. Additionally, some authorities believe that erythroplasia of Queyrat and Bowen’s disease remain useful terms in men.

Warty dyskeratoma, also known as an Isolated dyskeratosis follicularis, is a benign epidermal proliferation with distinctive histologic findings that may mimic invasive squamous cell carcinoma and commonly manifests as an umbilicated (Having a central mark or depression resembling a navel) lesion with a keratotic plug, WD have some histopathologic similarities to viral warts but it's not caused by HPV and the majority of these lesions display overall histopathologic features consistent with a follicular adnexal neoplasm. usually limited to the head, neck, scalp or face and vulva. Lesions are generally and sporadic and may be associated with a follicular unit. Oral involvement, particularly the hard palate, and genital involvement have been reported. it can also be thought of as one of the manifestations of focal acantholytic dyskeratosis, an epidermal reaction pattern that can be seen in several disorders, including Darier's disease and Grover's disease. But the main Difference between Darier disease and Warty dyskeratoma, is that Darier disease inherited dermatosis (autosomal dominant) consisting of multiple keratotic papules on the face, trunk, and extremities, while WD occurs as an isolated, noninherited, single keratotic nodule mainly confined to the head and neck as mentioned earlier.