Medically reviewed by Dr. A.M. van Coevorden, dermatologist
Penile intraepithelial neoplasiaa precancerous stage of penile cancer, often caused by HPV
Penile intraepithelial neoplasia (PeIN) is a rare condition in which abnormal cells are present in the skin of the penis. PeIN is not cancer in itself, but in some cases it can develop into penile cancer. Treatment is therefore recommended. The main cause is the human papillomavirus (HPV).
What is PeIN and what does it look like?
Penile intraepithelial neoplasia (PeIN) is a rare condition in which abnormal cells are present in the skin of the penis. PeIN is not cancer in itself, but over time it can develop into penile cancer. It often appears as red patches, thickenings, wart-like spots or small ulcers, usually on the glans or foreskin, but also elsewhere on the penis. It is often painless, but the spots can itch or be tender.
How does PeIN develop?
The most common cause is infection with the human papillomavirus (HPV), especially type 16, which is often passed on through sexual contact. Other risk factors are chronic inflammatory skin diseases such as lichen sclerosus, reduced immunity (for example after an organ transplant or from medicines), a narrowed foreskin, and smoking.
Is PeIN contagious?
PeIN itself is not contagious. However, the condition is usually caused by HPV, a virus that can be passed on through sexual contact.
How is the diagnosis made?
The diagnosis is made with a biopsy: under local anaesthetic a small piece of skin is removed and examined under the microscope. The doctor also looks for signs of other conditions, such as lichen sclerosus, and may refer you to a specialist centre if in doubt.
Do you need treatment?
Yes. Treatment of PeIN is recommended to reduce the risk of penile cancer. There are several options, depending on the type, size and location; together with your doctor you choose one that suits your situation.
What treatments are there?
For smaller spots a cream with 5-fluorouracil or imiquimod can be used, applied on a fixed schedule for several weeks; sometimes the spot seems to worsen before it improves. Laser therapy destroys the abnormal cells with a laser. Sometimes surgery is chosen, such as circumcision or local removal. Freezing with nitrogen (cryotherapy) or scraping (curettage) is also possible, and treatments can be combined.
HPV vaccination
There are two vaccines against HPV: Gardasil 9 and Cervarix. They protect against the virus that can lead to PeIN and penile cancer. HPV vaccination is offered to all boys in the national immunisation programme. There is currently not enough evidence to routinely vaccinate people who already have PeIN, so outside the programme the vaccination is not reimbursed.
Follow-up and aftercare
Despite treatment, PeIN can return, and new spots can develop. After treatment a follow-up plan checks for recurrence and new spots. Regular self-examination is also advisable.
What can you do yourself?
Check the skin of your penis regularly for new changes and contact your doctor if in doubt. Stopping smoking lowers the risk of PeIN and penile cancer.
Frequently asked questions about PeIN
Is PeIN cancer?
No, PeIN itself is not cancer, but a precancerous stage that can develop into penile cancer in some cases. That is why it is treated.
Is PeIN contagious?
The condition itself is not, but its main cause, HPV, is a virus that can be passed on through sexual contact.
Why does it need treating?
To reduce the risk of penile cancer. Treatment depends on the size and location of the spot.
What treatments are there?
A cream with fluorouracil or imiquimod, laser therapy, surgery such as circumcision, or freezing and scraping.
Does the HPV vaccine help?
The vaccine protects against HPV and is offered to all boys in the national immunisation programme. For those who already have PeIN, there is not yet enough evidence to vaccinate routinely.