Verrucous papilloma is a benign growth that often appears as a small, wart-like bump on the skin or inside the mouth. The early symptoms of verrucous papilloma are usually a rough or cauliflower-like spot that tends to grow slowly and is often painless, though some people notice irritation if it rubs on teeth, dentures, or clothing. Verrucous papilloma can affect adults of any age, and the exact look and location can vary. Not everyone will have the same experience. It is not usually life-threatening, and treatment is commonly simple removal if it causes symptoms, keeps growing, or needs testing to confirm the diagnosis.
How many people live with Verrucous papilloma?
There is no widely accepted worldwide estimate for how many people live with verrucous papilloma, because this wart-like growth is usually not tracked in global disease registries and is often grouped with other similar growths rather than counted on its own. The same is true in the United States, where a single reliable national estimate is not consistently reported for verrucous papilloma as a separate condition.
Overview
Verrucous papillomaSymptoms
Verrucous papilloma usually appears as a small, rough, wart-like growth on the skin or inside the mouth. It is often painless, though some people notice irritation, bleeding, or rubbing if it catches on food, teeth, or clothing.
Outlook and prognosis
Verrucous papilloma is usually benign and often does very well after complete removal. Most people have no lasting health problems, though it can come back if some tissue remains. Follow-up helps check healing and catch any recurrence early.
Causes and risk factors
Verrucous papilloma is most often linked to low-risk human papillomavirus, especially HPV 6 and 11. Risk can rise with skin or mouth contact that spreads HPV, minor ongoing irritation, and, for oral verrucous papilloma, smoking.
Genetic influences
Genetics do not appear to play a major role in verrucous papilloma. Most cases are not inherited, and there is no well-established pattern linking common genetic variations to verrucous papilloma risk.
Diagnosis
Verrucous papilloma is usually diagnosed by a clinician examining the growth and reviewing how it looks and feels. If the diagnosis of verrucous papilloma is uncertain, a small biopsy may be done to confirm it and rule out similar lesions.
Treatment and drugs
Verrucous papilloma is usually treated by removing the growth, often with a small procedure under local anesthesia. Many living with verrucous papilloma do well after complete removal. Follow-up helps check for regrowth or, rarely, similar nearby lesions.
Symptoms
Many people with Verrucous papilloma first notice a small, rough bump that seems to sit on the surface of the skin or inside the mouth. It often grows slowly and may not hurt at all, which is why the early symptoms of Verrucous papilloma can be easy to miss. Symptoms vary from person to person and can change over time.
Some growths do not cause pain, itching, or other clear symptoms at first. Loved ones often notice the changes first, especially if the spot is in a hard-to-see area.
The most common sign is a small, wart-like growth that feels rough or pebbly to the touch. With Verrucous papilloma, the surface can look white, pink, or skin-colored depending on where it appears.
The lesion usually gets bigger little by little rather than changing overnight. Because the change is gradual, many people notice it only after it starts catching on nearby tissue or becoming easier to see.
Many people have no pain at first, but the area can become tender if it is rubbed, bitten, or scraped. Day to day, it can feel like a spot that keeps getting in the way more than a deep ache.
How people usually first notice Verrucous papilloma?
People usually first notice verrucous papilloma as a small, wart-like bump that seems to appear out of nowhere, often on the lips, inside the mouth, throat, or genital skin depending on where it develops. For many, the first signs of verrucous papilloma are that the growth feels rough or looks cauliflower-like, while it usually does not hurt, though some may notice irritation, a feeling of something rubbing, or occasional bleeding if it gets bumped. Because these growths can look similar to other skin or mucosal lesions, a doctor or dentist is often the first to recognize that it is more than a simple skin tag or sore.
Types of Verrucous papilloma
Verrucous papilloma does not have a set of widely accepted medical subtypes in the way some other conditions do. In practice, doctors usually describe it by where the growth appears, how large it is, and whether there is just one lesion or several nearby. Symptoms don’t always look the same for everyone, but many people have few symptoms beyond noticing a small, wart-like bump. If you are wondering about the types of verrucous papilloma, the main point is that this condition is usually discussed by appearance and location rather than by formal disease variants.
No distinct types
There are no broadly recognized formal types of verrucous papilloma used in everyday care. Many living with verrucous papilloma notice a rough or cauliflower-like growth, while symptoms differ mainly by site, such as irritation in the mouth or rubbing on the skin. A healthcare professional may describe the lesion’s location and size instead of assigning it to a separate subtype.
Can I slow down the onset of symptoms?
No, there is no good evidence that lifestyle changes or medicines can meaningfully delay the start of symptoms from verrucous papilloma, and no diet, supplement, or exercise plan has been shown to prevent it. Research suggests the chance of developing one may be lower by reducing exposure to human papillomavirus, or HPV, avoiding tobacco if the growth is in the mouth, and keeping up with regular dental or medical checkups so any new wart-like bump can be found and treated early, but that is different from preventing the condition. If you notice a new rough, wart-like growth, getting it checked sooner can help with simple treatment and peace of mind, even though it cannot guarantee the growth will not return.
What genetics can tell you about symptoms
For verrucous papilloma, genetics usually does not give a clear picture of which symptoms someone will have, how severe they will be, or when they will start. These growths are most often linked to local cell changes, sometimes related to human papillomavirus, rather than an inherited gene change passed through families. In day-to-day life, symptoms tend to depend more on where the growth is and how large it becomes, so one person may notice only a small rough bump while another may have irritation or bleeding if it is in a spot that rubs easily.
Causes and risk factors
Verrucous papilloma often develops after infection with certain low-risk types of human papillomavirus, or HPV. Small breaks in the skin or in the lining of the mouth can make it easier for the virus to get in and trigger extra tissue growth. Common risk factors for verrucous papilloma include smoking and long-term irritation in the area, especially in the mouth. It’s rarely just one factor, and a weakened immune system can also make these growths more likely or harder to clear. Verrucous papilloma is not usually inherited, so genes are not thought to be a main cause.
What are the most common causes or risk factors?
Verrucous papilloma is most often linked to human papillomavirus, or HPV, a common virus that can cause wart-like growths on the skin or in moist areas such as the mouth or genitals. Risk can be higher with close contact that spreads HPV, small breaks or long-term irritation in the affected area, smoking when the growth is in the mouth, and a weakened immune system, which makes it harder for the body to clear the virus. Inherited genetic causes are not usually a main factor for this condition.
Environmental and biological risk factors
Verrucous papilloma is most often linked to viral exposure and to changes in the local tissue where the growth develops. Doctors often group risks into internal (biological) and external (environmental). The main risk factors for verrucous papilloma can vary somewhat by body site, but HPV exposure, immune status, and ongoing irritation are the best-known ones.
Infection with low-risk human papillomavirus, especially types 6 and 11, is the clearest biological risk factor. If the virus reaches the surface lining of the mouth, throat, or other moist tissues, a verrucous papilloma can develop.
HPV spreads through direct contact with affected skin or mucosal surfaces. Repeated exposure can raise the chance of verrucous papilloma, especially in tissues that are delicate or already irritated.
When the immune system is reduced by illness or medicines, the body may have more trouble clearing HPV. This can make verrucous papilloma more likely and may also increase the chance of new lesions over time.
Constant rubbing or minor injury from a rough tooth, dental appliance, or repeated friction can disturb the surface lining. This kind of local irritation may make it easier for a papilloma to form in that area.
Genetic risk factors
For most people, verrucous papilloma appears without a clear inherited reason. Current evidence does not point to one common gene change that causes most cases. Carrying a genetic change doesn’t guarantee the condition will appear. Rarely, inherited immune-system conditions may make these growths more likely.
Usually not inherited: Most verrucous papillomas are not caused by a gene change passed from parent to child. For many living with verrucous papilloma, this means close relatives are not automatically at higher risk.
Rare immune syndromes: A small number of inherited immune-system disorders can make it harder to control certain viruses, which may raise the chance of papilloma-like growths. This is uncommon and usually comes with other clues, such as frequent, persistent, or unusual infections.
Somatic DNA changes: Some growths may begin after DNA changes happen only in the affected cells, rather than in every cell of the body. These cell-level changes are not inherited and are not usually part of routine testing for verrucous papilloma.
Family patterns: There is no well-established single-gene cause behind most cases, so when people ask is verrucous papilloma hereditary, the answer is usually no. If several relatives have repeated wart-like growths or known immune problems, a genetics or specialist review may be worth discussing.
Lifestyle risk factors
Several everyday habits may affect the chance of developing verrucous papilloma, especially in the mouth or throat. The most relevant lifestyle risk factors for verrucous papilloma are those that increase viral exposure or repeatedly irritate the surface lining of the tissue. While not every case is linked to a clear habit, how lifestyle affects verrucous papilloma often comes down to local tissue damage, hygiene, and behaviors that raise HPV transmission risk.
Smoking or chewing tobacco can repeatedly irritate the lining of the mouth and throat. This may make it easier for abnormal wart-like growths such as verrucous papilloma to develop or persist.
Heavy alcohol use can irritate oral tissues, especially when combined with smoking. Ongoing irritation may increase the likelihood of mucosal changes that support lesion formation.
Sexual practices that increase exposure to oral HPV may raise the risk of some verrucous papillomas. Limiting HPV exposure and using barrier protection can lower this risk in some people.
Inadequate oral care can contribute to chronic inflammation and a less healthy tissue surface in the mouth. This may support the development or recurrence of lesions in susceptible areas.
Risk prevention
Verrucous papilloma usually cannot be prevented with certainty, but some steps may lower the chance of developing it or help catch related changes early. This matters most for people who have ongoing mouth irritation, tobacco exposure, or possible exposure to certain human papillomavirus, or HPV, types. Prevention is about lowering risk, not eliminating it completely.
HPV vaccination may lower the risk of some papilloma-like growths linked to HPV infection. It works best before exposure, but many people can still benefit based on age and health history.
Limiting direct exposure to HPV through safer oral and sexual contact may help reduce the risk of verrucous papilloma in some people. Barriers such as condoms or dental dams can lower risk, even though they do not block all skin-to-skin spread.
Smoking and chewing tobacco can irritate the lining of the mouth and raise the chance of abnormal tissue changes. Avoiding tobacco is one of the clearest ways to reduce the risk of verrucous papilloma and other oral growths.
Poorly fitting dentures, rough teeth, or repeated rubbing in one spot can keep tissue irritated over time. Fixing these problems with dental care may help lower a trigger that can contribute to verrucous papilloma.
Can you prevent Verrucous papilloma?
You cannot fully prevent verrucous papilloma, and many living with it did nothing to cause it. Risk may be lower by reducing exposure to human papillomavirus, or HPV, which is a common virus that can sometimes play a role in these wart-like growths; this can include safer sex, not sharing items that touch the mouth, and getting the HPV vaccine if it is recommended for you. Avoiding tobacco may also help protect the tissues in the mouth, but these steps cannot guarantee prevention.
Transmission
Verrucous papilloma is usually not considered highly contagious in day-to-day life. Many cases are linked to human papillomavirus, or HPV, which can pass through direct contact with the affected skin or lining of the mouth, and sometimes through intimate contact, but the growth itself does not spread through the air, coughing, or casual contact like sitting next to someone.
For many living with verrucous papilloma, the more practical question is how verrucous papilloma spreads, and the answer is that any spread is usually limited and depends on whether HPV is present. Brief everyday contact carries a low risk, but if you have a new wart-like growth, it is still sensible to avoid picking at it or sharing items that touch the area until a clinician has checked it.
When to test your genes
For verrucous papilloma, genetic testing is usually not needed. Early detection and tailored care rely on a clinical exam and, when needed, a biopsy; testing genes may only be considered if there is an unusual pattern of many papillomas, other birth differences, or a strong family history suggesting a rare inherited syndrome.
Diagnosis
A small wart-like growth in the mouth, throat, or on the skin can be easy to dismiss at first, especially if it does not hurt. Verrucous papilloma is usually diagnosed by the way the growth looks and where it appears, then confirmed with a small tissue sample when needed. It’s natural to worry when symptoms don’t have a clear explanation, but the diagnosis of verrucous papilloma is often straightforward once a clinician examines the lesion.
Doctors ask when the growth first appeared, whether it has changed in size, and if it bleeds, rubs, or gets irritated. They also review smoking, alcohol use, oral irritation, and any past skin or mouth lesions that could affect the diagnosis.
A clinician closely examines the growth for its size, shape, color, and rough or finger-like surface. They also check the nearby skin or lining of the mouth to see whether there are other lesions or signs of irritation.
Verrucous papilloma often has a small, raised, cauliflower-like look that gives an important clue during the visit. Even so, appearance alone cannot always rule out other harmless growths or, less commonly, more serious changes.
A biopsy is the main test used to confirm verrucous papilloma. A doctor removes all or part of the growth and sends it to a lab, where the tissue is examined under a microscope.
How is Verrucous papilloma diagnosed?
Verrucous papilloma is usually diagnosed by a doctor or dentist looking closely at the growth and asking how long it has been there and whether it has changed. Because it can look like other bumps or wart-like growths, the diagnosis is often confirmed by removing all or part of it and checking the tissue under a microscope, which is called a biopsy. Imaging scans and genetic tests are not usually needed.
Stages of Verrucous papilloma
Verrucous papilloma does not have defined progression stages. This is because it is usually a localized growth that is identified by how it looks and where it appears, rather than by a step-by-step pattern of worsening over time. Doctors usually start with a conversation about when the bump first appeared, whether it has changed, and any irritation, bleeding, or discomfort, then confirm the diagnosis with an exam and often a small tissue sample if needed. When people ask about the early symptoms of verrucous papilloma, the main clue is often a slow-growing, rough or cauliflower-like bump that stays in one area rather than spreading through the body in stages.
Outlook and prognosis
The outlook for verrucous papilloma is excellent, because it is a benign lesion and is usually cured by complete surgical removal. Recurrence is uncommon, but it can happen if the lesion is not fully excised or if ongoing local irritation persists. Malignant transformation is considered very rare, and most patients do not experience long-term health consequences after treatment. Mortality from verrucous papilloma itself is not expected, as it does not typically behave aggressively or spread to other parts of the body. Regular follow-up may be advised when the diagnosis is uncertain, the lesion is in a high-friction area, or there are atypical features that warrant monitoring.
Long-term effects
Verrucous papilloma is usually a benign, wart-like growth, so the long-term outlook is often very good. For many, symptoms stay local and may be more bothersome than dangerous, especially if the growth rubs on clothing, gets bitten, or catches during shaving or brushing teeth. It’s important to remember that long-term doesn’t always mean progressive. When considering what lies ahead, the main issues are comfort, appearance, and whether the growth comes back after treatment.
Many people with verrucous papilloma have ongoing rubbing, tenderness, or occasional minor bleeding if the growth sits in a high-friction area. Day to day, this can mean a spot that gets snagged when dressing, shaving, eating, or brushing teeth.
A visible verrucous papilloma can affect comfort with smiling, speaking, or wearing certain clothes, depending on where it is. Even when the lesion is harmless, its appearance may continue to bother some people over time.
After removal, verrucous papilloma often does not return, but it can come back if some of the growth remains. This is one reason follow-up may be advised, especially after treatment of larger lesions.
Long-term effects can involve problems linked to where the growth is located rather than the growth itself. For example, a lesion in the mouth may be repeatedly bitten or irritated, while one on the skin may catch on clothing or jewelry.
How is it to live with Verrucous papilloma?
Living with verrucous papilloma is often more bothersome than dangerous, because this growth is usually benign and many people notice it mainly when it catches on the tongue, lips, clothing, or during eating, speaking, or brushing their teeth, depending on where it appears. Some people feel self-conscious if it is visible, and there can be mild irritation or anxiety while waiting for a diagnosis, but daily life is often otherwise normal once it is evaluated and, if needed, removed. For people around you, the main effect is usually worry rather than direct impact, and that often eases when a clinician confirms what it is and explains the treatment plan.
Treatment and drugs
Verrucous papilloma is usually treated by removing the growth, especially if it is bothersome, catches on clothing, bleeds, or needs to be checked to confirm it is benign. Treatment is often a minor in-office procedure, such as cutting or shaving it off, and in some cases freezing or laser treatment may be used depending on where it is and how large it is. Your doctor can help weigh the pros and cons of each option, since not every treatment suits every spot on the body or mouth. Medicines are not usually the main treatment for verrucous papilloma, and the removed tissue is often sent to a lab so the diagnosis can be confirmed.
Can you cure Verrucous papilloma?
Yes. A verrucous papilloma is a noncancerous, wart-like growth, and it can often be cured by removing it completely with a small procedure. Most people do well after treatment, but it can sometimes come back, so follow-up may be needed.
Non-drug treatment
Verrucous papilloma is usually managed with simple office-based or surgical procedures rather than medicines. For many, treatment begins not at the pharmacy, but with removing the growth and checking it under a microscope, because it can look similar to other wart-like lesions. The best treatment for verrucous papilloma depends on where it is, how large it is, and whether it keeps getting irritated. Ongoing follow-up may also be advised, especially if the growth comes back or the diagnosis was not fully clear at first.
This is the most common treatment and involves cutting out the growth completely. It both removes the lesion and allows lab testing to confirm the diagnosis. Many people can have this done with local numbing in a clinic or dental office.
Small surface lesions can sometimes be shaved off instead of removed more deeply. This may be an option when the growth is raised and easy to access. A sample is still often sent for microscopic review.
A laser can remove or vaporize the lesion, especially in delicate areas or when bleeding control matters. It may be used when a precise approach is helpful. Some people need follow-up visits to make sure the area heals well and the growth does not return.
Cryotherapy uses very cold treatment to destroy the abnormal tissue. It is used more often for skin lesions than for growths inside the mouth. More than one session may be needed if the lesion is thicker.
Your genes may have an impact on how drugs work for you
For people with verrucous papilloma, treatment is usually local, such as careful removal or medicine placed right on the growth, so inherited differences in how the body handles medicine do not usually play a big part in care. In the uncommon situation where a person needs pain medicine, numbing medicine, or treatment for a related skin infection, natural differences in the body can affect how well a drug works or the chance of side effects, but this is not a main feature of this condition. Because of that, genetic drug-response testing is not routinely used for verrucous papilloma.
Pharmacological treatments
For most people living with verrucous papilloma, medicines are not the main treatment. These growths are usually managed with simple removal or careful follow-up, especially when they are small and clearly benign. When a verrucous papilloma looks more like a wart on the skin or genital area, a few drug treatments may be considered in selected cases. Not everyone responds to the same medication in the same way.
There is no standard pill or routine medicine that reliably treats verrucous papilloma in most body sites. Many living with verrucous papilloma are treated with removal instead, because medicines often do not clear the growth completely.
Imiquimod is a prescription cream that helps the immune system react against some wart-like growths, mainly on external skin or genital tissue. It is not a usual treatment for oral verrucous papilloma, but it may be considered in selected cases when a lesion behaves more like an HPV-related wart.
Podofilox, also called podophyllotoxin, is a topical medicine used for certain external genital warts and may sometimes be discussed when the early symptoms of verrucous papilloma overlap with wart-like lesions in that area. It should only be used on the exact site and in the way a clinician recommends, because it can irritate healthy skin.
Trichloroacetic acid is a medicine applied by a healthcare professional to destroy superficial wart tissue. It may be used for selected small external lesions, but it is not a standard choice for most verrucous papilloma growths, especially inside the mouth.
Genetic influences
Most cases of verrucous papilloma are not thought to be inherited, so family history is usually not the main reason one develops. It’s natural to ask whether family history plays a role. In many living with verrucous papilloma, doctors look first at non-inherited factors, such as ongoing irritation or infection with certain low-risk types of HPV, rather than a gene passed down through a family. The cells in the growth can pick up changes over time, but these changes are usually limited to that spot and are not something you would pass on to children. If you are wondering whether verrucous papilloma is hereditary, the answer is usually no, although rare inherited conditions that affect the skin, mouth lining, or immune system can sometimes make papilloma-like growths more likely.
Is Verrucous papilloma genetic?
Genetics do not appear to play a major role in verrucous papilloma. Most cases are not inherited, and there is no well-established pattern linking common genetic variations to verrucous papilloma risk.
Having a genetic risk is not necessarily a diagnosis
Changes in genes are a normal and common part of human biology. Most of these variants do not directly affect health and simply reflect the natural differences seen across people. For many genes, having a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors are involved. In some cases, though, a single well-studied variant in a specific gene is enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For many living with verrucous papilloma, the treatment plan usually depends on where the growth is, whether it is causing irritation, and whether it has come back after earlier care. When people look up treatment options for verrucous papilloma, it helps to know that genetics rarely changes the plan, because medicines are not usually the main treatment and care is more often local, such as removal or close follow-up. Not every difference in response is genetic, but in verrucous papilloma, doctors do not routinely use pharmacogenetic testing to choose a drug. If a growth looks unusual, keeps returning, or raises concern for a more serious condition, the tissue may be examined more closely, mainly to confirm the diagnosis and rule out cancer rather than to match treatment to an inherited gene change. In short, treatment for verrucous papilloma is guided much more by the lesion’s size, location, symptoms, and biopsy findings than by genetics.
Interactions with other conditions
Verrucous papilloma usually affects daily life more by being an irritating, wart-like growth than by causing wider illness, but it can overlap with other conditions that need a closer look. In the mouth, throat, or on the skin, it may resemble common warts, genital warts, or thicker growths that can sometimes be precancerous or cancerous, so doctors often check carefully if the lesion is growing, bleeding, or not healing. Certain diseases may overlap, meaning a verrucous papilloma can look similar to verrucous carcinoma or squamous cell carcinoma even though it is usually benign. Many living with immune system problems, such as HIV infection or treatment-related immune suppression, may be more likely to develop persistent or multiple papilloma-like growths. If early symptoms of verrucous papilloma appear alongside other unusual sores or repeated lesions, a biopsy may be needed to make sure another disease is not being missed. Verrucous papilloma itself does not usually spread through the body or directly trigger other illnesses, but its links with human papillomavirus in some cases can matter when doctors think about related infections and follow-up care.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Verrucous papilloma?
Depending on where it appears, verrucous papilloma can look a lot like a common wart, a skin tag, or another harmless rough, wart-like growth. Doctors also make sure it is not a precancer or a slow-growing cancer, especially if the bump is getting bigger, bleeds, becomes painful, or does not go away.
History
Long before modern lab tests, doctors and dentists were already describing small, wart-like growths on the skin and moist linings of the body, including the mouth and throat. What we now call verrucous papilloma gradually became easier to recognize as medicine moved from simple visual descriptions to microscope-based diagnosis. In everyday life, this mattered because a growth that looked alarming to someone brushing their teeth or noticing a rough bump on the tongue was often found to be benign rather than cancer.
Early reports did not always separate verrucous papilloma clearly from other growths that can look similar. Some were grouped together with common warts, while others were confused with thicker, more serious lesions. Not every early description was complete, yet together they helped doctors learn which growths tend to stay harmless and which ones need closer evaluation.
As pathology developed in the late 1800s and early 1900s, specialists began classifying these lesions by their surface pattern and the way they appeared under the microscope. This was an important step, because verrucous papilloma can have a rough, finger-like, or cauliflower-like surface that overlaps with other conditions. Over time, doctors became better at telling it apart from lesions caused by irritation, infections, and cancers that may have a similar look at first glance.
Later in the 20th century, research into wart-like lesions of the mouth, throat, and skin added another layer of understanding. Scientists learned that some papillomas are linked to viral infection, while others may arise in different settings. For many living with verrucous papilloma, this history explains why doctors may recommend careful examination or biopsy: the goal is not only to name the growth, but also to be sure it is not one of the less common conditions that needs different treatment.
Today, the history of verrucous papilloma is really a story of improving accuracy. What once relied mostly on appearance is now supported by pathology and, when needed, additional testing. That progress has made it easier to reassure people when the lesion is benign, while also helping clinicians spot warning signs when a wart-like growth does not fit the usual pattern.