An inverted papilloma is a type of tumor in which surface epithelial cells grow downward into the underlying supportive tissue. It may occur in the nose and/or sinuses or in the urinary tract (bladder, renal pelvis, ureter, urethra). When it occurs in the nose or sinuses, it may cause symptoms similar to those caused by sinusitis, such as nasal congestion. When it occurs in the urinary tract, it may cause blood in the urine.

Internationally tumors of the choroid plexus are rare, accounting for 0.4-0.6% of all intracranial neoplasms. It most commonly affects young children under the age of 5 with a mean patient age of 5.2 years.

The exact cause of nasal polyps is unclear. They are, however, commonly associated with conditions that cause long term inflammation of the sinuses. This includes chronic rhinosinusitis, asthma, aspirin sensitivity, and cystic fibrosis.

Various additional diseases associated with polyp formation include:

Chronic rhinosinusitis is a common medical condition characterized by symptoms of sinus inflammation lasting at least 12 weeks. The cause is unknown and the role of microorganisms remains unclear. It can be classified as either with or without nasal polyposis.

Cystic fibrosis (CF) is the most common cause of nasal polyps in children. Therefore, any child under 12 to 20 years old with nasal polyps should be tested for CF. Half of people with CF will experience extensive polyps leading to nasal obstruction and requiring aggressive management.

A papilloma (plural papillomas or papillomata) ("" + "") is a benign epithelial tumor growing exophytically (outwardly projecting) in nipple-like and often finger-like fronds. In this context refers to the projection created by the tumor, not a tumor on an already existing papilla (such as the nipple).

When used without context, it frequently refers to infections (squamous cell papilloma) caused by human papillomavirus (HPV), such as warts. Human papillomavirus infection is a major cause of cervical cancer, although most HPV infections do not cause cancer. There are, however, a number of other conditions that cause papilloma, as well as many cases in which there is no known cause.

Choroid plexus papillomas are benign tumors that are usually cured by surgery; malignant progression has been rarely reported.

These lesions usually present in neonates, although they may not come to clinical attention until adulthood (for cosmetic reasons). There is no gender predilection. They are present in approximately 3-6 per 1000 live births.

Heck's disease (also known as focal or multifocal epithelial hyperplasia) is an asymptomatic, benign neoplastic condition characterized by multiple white to pinkish papules that occur diffusely in the oral cavity. Can present with slightly pale, smooth or roughened surface morphology. It is caused by the human papilloma virus types 13 and 32. It exhibits surface cells with vacuolated cytoplasm around irregular, pyknotic nuclei and occasional cells with mitosis-like changes within otherwise mature and well-differentiated epithelium. A distinguishing histologic feature is elongated rete ridges resembling Bronze Age axe with mitosoid bodies present. It was first identified in the Aboriginal population.

Over time, they will spontaneously regress without treatment. Possible treatment may be excisional biopsy for lesions of functional or aesthetic concern.

Immunoperoxidase stains have identified antigens of the human papillomavirus (HPV) types 6 and 11 in approximately 50% of cases of squamous cell papilloma.

Normally found in children or young adults, a common cause of conjunctival squamous cell papilloma is during childbirth, when the mother passes the virus to her child.

There are two primary types of nasal polyps: ethmoidal and antrochoanal. Ethmoidal polyps arise from the ethmoid sinuses and extend through the middle meatus into the nasal cavity. Antrochoanal polyps usually arise in the maxillary sinus and extend into the nasopharynx and represent only 4-6% of all nasal polyps. However, antrochoanal polyps are more common in children comprising one-third of all polyps in this population. Ethmoidal polyps are usually smaller and multiple while antrochoanal polyps are usually single and larger.

Inverted papillomas are definitively diagnosed by histologic examination. However, Magnetic Resonanace Imaging (MRI) may show a characteristic feature described as a Convoluted Cerebriform Pattern (CCP). A retrospective study published in the American Journal of Neuroradiology concluded that identification of CCP by MRI in a patient with a nasal tumor made the diagnosis of Inverted papilloma quite likely. The study reported the sensitivity and specificity to be 100% and 87% respectively. CCP can be associated with other malignant tumors as well.

Pneumosinus dilatans is a condition consisting of abnormal expansion or dilatation of one or more paranasal sinuses. It most often affects the frontal sinus, and can cause damage to vision due to pressure on the nearby optic nerve. The preferred treatment is endoscopic surgery to deflate the sinus.

Nipple adenomas most commonly occur in 30- to 40-year-old women, but can also occur in men. They can also occur at any age, including in the elderly, in adolescence, and in infants.

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).

Conservative (i.e. no treatment), or surgical . With surgical excision, recurrence is common, usually due to incomplete excision. Often, the tracts of the cyst will pass near important structures, such as the internal jugular vein, carotid artery, or facial nerve, making complete excision impractical.

This is a very rare tumor, since only about 1 in 35,000 to 40,000 people have VHL, of whom about 10% have endolymphatic sac tumors. Patients usually present in the 4th to 5th decades without an gender predilection. The tumor involves the endolymphatic sac, a portion of the intraosseous inner ear of the posterior petrous bone.

Smoking and alcohol abuse as the major risk factors. Viral causes has recently been taken under consideration as one of the risk factors. Viruses such as Epstein-Barr virus (EBV) (majorly involved in causing nasopharyngeal carcinoma) and human papilloma virus are included in this category. Chewing of betel nut ("Areca catechu") quid has been directly associated to cause oral cancers. It has also been stated under the FDA poisonous plant data base by the U.S Food and Drug Administration

An unbalanced diet, deficit in fruits and vegetables has shown to increase the risk of cancer.

A nipple adenoma is a type of intraductal papilloma that arises within the lactiferous ducts that are located within the nipple.

Common seborrheic keratosis (also known as "Basal cell papilloma," and "Solid seborrheic keratosis") is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface.

Treatment may include the following:

- Surgery with or without radiation

- Radiotherapy

Fast neutron therapy has been used successfully to treat salivary gland tumors, and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.

- Chemotherapy

A branchial cleft cyst is a cyst in the skin of the lateral part of the neck. It can but does not necessarily have an opening to the skin surface called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second branchial cleft, i.e. failure of fusion of the second and third branchial arches. Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly.

Little is known about the total incidence of salivary gland tumours as most benign tumours go unrecorded in national cancer registries. The majority of salivary tumours are benign (65-70%). Within the parotid gland 75 - 80% of tumours are benign. Around 50% of the tumours found in the submandibular glands are benign. Sublingual gland tumours are very rare but if present, they are most likely to be malignant.

In the United States, salivary gland cancers are uncommon with an incidence rate of 1.7 in 100000 between 2009 and 2013.

Lip pits are harmless and do not usually require any treatment, although in some reported cases surgical excision has been used.

The cause of choroid plexus carcinomas are relatively unknown, although hereditary factors are suspected. The sometimes occur in conjunction with other hereditary cancers, including Li–Fraumeni syndrome and malignant rhabdoid tumors. A mutation in the tumor suppressor gene TP53 is usually characterized in this disease.

OAF is a complication of oroantral communication. Other complications may arise if left untreated. For example:

- Candidal infection

- Chronic maxillary sinus infection of bacterial origin

- Osteomyelitis

- Rhinosinusitis

- Sinus pathology

Therefore, OAF should be dealt with first, before treating the complications.