Where is a perineal cyst? Understanding Location, Symptoms, and Causes

September 27, 2025 •

4 min read

According to the National Institutes of Health, while relatively rare, epidermoid cysts can form in the perineal region. Understanding precisely where is a perineal cyst and what it involves is the first step toward finding relief and appropriate medical care.

Quick Summary

A perineal cyst is a lump located in the perineum, the area of skin and tissue between the anus and the genitals. Its specific location can vary, and it is crucial to differentiate it from other conditions that cause bumps or pain in this sensitive area.

Key Points

Location: A perineal cyst is a lump in the perineum, the area between the anus and the genitals.
Types of Cysts: Common types include epidermoid cysts (skin-based) and perineural (Tarlov) cysts, which are near spinal nerves but can cause referred perineal pain.
Causes: Cysts can be caused by trauma, blocked hair follicles, or infection in the sensitive perineal area.
Symptoms: Common symptoms are swelling, pain (especially when sitting), and possible redness or discharge if infected.
Treatment: Depending on the type and severity, treatment can range from warm compresses to surgical drainage or complete excision to prevent recurrence.
See a Doctor: Seek medical attention if a perineal lump is persistent, growing, or shows signs of infection like fever or foul-smelling discharge.

The Anatomy of the Perineal Region

To understand where a perineal cyst is located, it is helpful to first define the perineum. This anatomical region, composed of skin, nerves, and vessels, is situated at the outlet of the pelvis.

In a male, the perineum is the area between the anus and the scrotum.
In a female, it is the area between the anus and the vulva.

A cyst forming in this area will present as a lump on or near the surface of this skin patch. Because the perineum is a high-pressure, high-friction area, it can be susceptible to irritation and trauma, which may contribute to cyst formation.

Types of Cysts and Lumps Found in the Perineal Area

A perineal cyst is a general term, as several types of cysts and other conditions can manifest as a lump in this region. Correctly identifying the type is critical for effective treatment.

Epidermoid Cysts

Epidermoid cysts are the most common type of cutaneous cyst and are composed of a sac filled with keratin. They are a rare finding in the perineal region, but cases have been documented. They are typically benign and slow-growing but can become infected, inflamed, or rupture, causing pain and discomfort.

Perineural (Tarlov) Cysts

Perineural cysts are fluid-filled sacs on the nerve root sheath, usually in the sacral region. While not directly on the perineum, these cysts can compress nerves and cause pain, numbness, or tingling that is referred to the lower back, buttocks, legs, or perineal area.

Pilonidal Cysts

A pilonidal cyst is an abscess or cyst that occurs in the buttock crease, near the tailbone. While this is technically located adjacent to the perineum, an infection can cause pain and swelling that radiates to the surrounding areas, including the perineum.

Anal Duct Cysts and Other Conditions

Some cysts arise from the anal ducts or glands and can appear near the anal verge. Other lumps in the perineal area are not cysts but could be hemorrhoids, abscesses, or skin tags. A perineal abscess is a painful, pus-filled lump from an infected anal gland, requiring prompt drainage.

Causes of Perineal Lumps

Various factors can contribute to the formation of cysts or lumps in the perineal area:

Trauma or Injury: Mechanical pressure, minor trauma, or surgical procedures can lead to epidermoid cysts. Chronic injury from activities like cycling can also play a role.
Blocked Hair Follicles: Irritation or infection of a hair follicle can lead to a cyst or abscess, a cause for conditions like pilonidal cysts.
Infection: Bacterial infections can cause an abscess. STIs can also cause bumps in the genital and anal area.
Inflammation: Conditions like hidradenitis suppurativa can involve inflammation of skin glands in the perineal region, leading to abscesses.

Symptoms and Diagnosis

Symptoms vary depending on the cyst's size, type, and if it's infected. Common signs include:

A tender, swollen lump
Pain, especially when sitting or during bowel movements
Redness or irritation
Discharge if it ruptures
Fever or chills in severe infection cases

Diagnosis involves a physical examination. Imaging like MRI can help visualize the lesion and differentiate it. A biopsy may be performed to confirm the diagnosis.

Treatment Approaches

Treatment depends on the type, symptoms, and infection status. For small, asymptomatic cysts, observation may be recommended. For symptomatic or infected lesions, options include:

Warm Compresses: Can help promote drainage for infected cysts.
Surgical Incision and Drainage: For abscesses or infected cysts, a doctor can drain the pus.
Complete Excision: For chronic or recurrent cysts, surgical removal of the cyst wall is necessary to prevent recurrence and is the treatment of choice for many types of perineal cysts.
Antibiotics: May be prescribed with drainage to combat infection.

Perineal Cyst vs. Perianal Abscess: A Comparison


Feature	Perineal Cyst	Perianal Abscess
Location	Lump within the perineum (between genitals and anus)	Painful, pus-filled lump near the anal verge or rectum
Cause	Blocked skin glands or hair follicles, trauma, pressure	Clogged and infected anal gland
Contents	Keratin, fluid, or other cellular debris	Pus (a collection of white blood cells, bacteria, and dead tissue)
Symptoms	Often slow-growing, can be asymptomatic until infected	Usually presents with acute, throbbing, severe pain
Treatment	Surgical excision is often required for complete removal	Incision and drainage is the primary treatment

When to Seek Medical Attention

It is important to see a healthcare provider for any persistent or concerning lump in the perineal region. Seek immediate medical help for signs of worsening infection like fever, intense pain, significant swelling, or foul-smelling discharge. A doctor can provide an accurate diagnosis and prevent complications. For more information, consult the Cleveland Clinic(https://my.clevelandclinic.org/health/body/24381-perineum).

Conclusion

A perineal cyst is a lump located in the sensitive skin and tissue between the genitals and the anus. The term encompasses various conditions, from relatively rare epidermoid cysts to abscesses and referred pain from deeper issues like perineural cysts. Accurate diagnosis is essential for effective treatment, which can range from at-home care to surgical intervention. Consulting a healthcare provider is recommended for proper evaluation and management of any perineal lump, especially if it becomes painful or shows signs of infection.

Frequently Asked Questions

A perineal cyst typically feels like a small, firm lump or nodule beneath the skin. It may be painless at first, but it can become tender, swollen, and painful if it becomes infected or inflamed.

No, they are different. A perineal cyst is usually a slow-growing sac filled with keratin or fluid, whereas a perianal abscess is a painful, acute infection of an anal gland, resulting in a pocket of pus.

While some cysts may remain small and cause no symptoms, they typically do not disappear completely on their own. If a cyst becomes infected, it may drain spontaneously, but the cyst wall often remains, increasing the risk of recurrence.

It is advisable to see a doctor if you notice any new lump in the perineal region, especially if it is growing, painful, or accompanied by symptoms like redness, fever, or discharge. These could be signs of infection or other serious conditions.

For an infected cyst or abscess, a healthcare provider will typically perform an incision and drainage procedure to release the pus. In cases of recurrence, or for specific types like epidermoid cysts, complete surgical removal of the cyst is often necessary.

Yes, chronic pressure from prolonged sitting can contribute to the formation of cysts or lumps in the perineal and adjacent areas by causing irritation or blocked hair follicles.

While both can cause a lump, hemorrhoids are swollen veins that can cause bleeding, itching, or pain, particularly during or after bowel movements. Cysts are distinct fluid-filled sacs that do not typically bleed unless ruptured or infected, but a doctor's examination is needed for a definitive diagnosis.