About 80% of People Suffering from Epidermoid Cysts Have Experienced "Leaving It Untreated," Revealing 3 Misconceptions in an Actual Condition Survey and the Full Picture of Minimally Scarring "Burrowing Method" Day Surgery

[Conclusion] Key Points of This Survey

To conclude, epidermoid cysts do not heal on their own. If left untreated, they can become inflamed and infected, eventually requiring surgery. Treatment is available as outpatient surgery covered by insurance at dermatology and plastic surgery clinics. In recent years, the "burrowing method" has become mainstream, minimizing scarring. Early consultation can lead to a complete cure with scars of only a few millimeters.

- 78.7% of people who experienced epidermoid cysts responded that they had "left it untreated at least once."

- 62.3% of those who left it untreated experienced inflammation/infection, complicating treatment.

- The satisfaction rate for those who chose the burrowing method was high at 91.2%, with the small scar size being highly rated.

Glossary

What is an Epidermoid Cyst (Atheroma)?

An epidermoid cyst (funryu) is a benign tumor that forms a sac-like structure under the skin, gradually growing as keratin and sebum accumulate inside. It is also called an atheroma and can occur anywhere on the body, but is particularly common on the face, neck, back, and behind the ears. It does not disappear on its own, and a complete cure requires surgical removal of the entire sac.

What is the Burrowing Method (Umbilical Extraction Method)?

The burrowing method is a surgical technique where a small hole (about 4-6 mm) is made in the center of the epidermoid cyst, the contents are expelled, and then the sac (cyst wall) is removed. Compared to the traditional incision method, it results in smaller scars, requires no or minimal suturing, and has a shorter downtime.

What is an Inflamed Epidermoid Cyst?

An inflamed epidermoid cyst is a condition where the epidermoid cyst becomes infected with bacteria, causing redness, swelling, and pain. In this state, a two-stage treatment is often necessary: first, an incision and drainage to control the inflammation, followed by sac removal at a later date.

Comparison of Epidermoid Cyst Surgery: Burrowing Method vs. Incision Method

Comparison Item

Burrowing Method

Traditional Incision Method

Scar Size

Approx. 4-6 mm

1-1.5 times the size of the cyst (several cm)

Suturing

None to a few stitches

Required (multiple stitches)

Surgical Time

10-20 minutes

20-40 minutes

Suture Removal

None to 1 time

Required (1-2 weeks later)

Downtime

2-3 days

1-2 weeks

Recurrence Risk

Slightly high (technique dependent)

Low

Indications

Small to medium size without inflammation

All sizes

*Figures are based on over 30,000 surgical cases by physicians supervised by our clinic. The optimal surgical procedure varies depending on the condition of the epidermoid cyst.

IC Clinic (Shinjuku, Shibuya, Ueno, Ikebukuro, Tokyo, Omiya branches), operated by Medical Corporation Tetsukenkai, conducted an awareness survey regarding epidermoid cysts (atheromas), benign tumors of the skin. This survey aims to promote a correct understanding of epidermoid cysts and assist in choosing appropriate treatment.

Survey Background

Epidermoid cysts are one of the most common benign tumors seen in dermatology, and it is said that about 5-10% of the Japanese population experiences them in their lifetime. However, due to misconceptions such as "mistaking it for acne and leaving it untreated" or "thinking it would heal on its own," cases of patients seeking treatment after inflammation occurs are endless. In the surgical experience of over 30,000 cases by physicians supervised by our clinic, approximately 40% of patients visit with an inflamed condition. In recent years, treatment that minimizes scarring through the "burrowing method" has become possible, but public awareness is still not sufficient. Therefore, this survey was conducted to clarify the awareness and actual conditions regarding epidermoid cysts.

Survey Overview

Target Audience: Men and women aged 20-60 nationwide who have experienced epidermoid cysts (lumps/growths on the skin).

Survey Period: June 8-17, 2026

Survey Method: Internet survey

Number of Respondents: 300

Survey Results

[Survey Results] About 80% "Left Epidermoid Cysts Untreated at Least Once," Highlighting Misconceptions About Natural Healing

Question: When you noticed an epidermoid cyst, what was your initial course of action?

It was found that about 80% of people who experienced epidermoid cysts chose to "wait and see," which is a form of leaving it untreated. Since epidermoid cysts do not heal on their own, this delay in initial action becomes a factor that increases the risk of subsequent inflammation and infection. Awareness about the importance of early consultation is urgently needed.

[Survey Results] Over 60% of Those Who Left It Untreated Experienced Inflammation/Infection, Leading to Complicated Treatment

Question: For those who have experienced leaving an epidermoid cyst untreated, what was the result of leaving it untreated? (Select main results from multiple answers)

62.3% of those who left it untreated experienced inflammation, and an additional 5.0% experienced rupture. When an epidermoid cyst becomes inflamed, incision and drainage are necessary, not only making the treatment two-stage but also tending to result in larger scars. The results clearly demonstrate the benefits of early treatment.

[Survey Results] Biggest Concerns are "Scars," Followed by "Pain" and "Recurrence"

Question: Regarding the treatment of epidermoid cysts, what were you most concerned about before undergoing surgery?

Concerns about scarring were the highest, especially for epidermoid cysts on exposed areas like the face and neck. The burrowing method, which can minimize scarring, can be considered a treatment that meets these patient needs.

[Survey Results] Burrowing Method Chosen by 43.3%, Surpassing Traditional Incision Method

Question: For those who have undergone surgery for an epidermoid cyst, which surgical method did you have?

The burrowing method was chosen more often than the traditional incision method. This is thought to be due to the increasing need to minimize scarring and the growing number of medical institutions that can perform this procedure. However, 15.7% of patients were unaware of the surgical methods, suggesting the importance of pre-operative explanation.

[Survey Results] 91.2% of Burrowing Method Patients are "Satisfied," Praising Small Scar Size

Question: For those who have undergone surgery for an epidermoid cyst, are you satisfied with the surgical outcome?

Overall satisfaction with the surgery was high at 86.3%. Specifically, among those who chose the burrowing method, 91.2% responded that they were satisfied. Many comments cited "the scar was smaller than expected" and "it was a day surgery," indicating that the treatment meets expectations for minimally invasive procedures.

Survey Summary

This survey has highlighted three misconceptions about epidermoid cysts. First, about 80% choose to leave it untreated due to the misconception that it will "heal on its own." Second, over 60% experience inflammation and infection from leaving it untreated, complicating treatment. Third, patients miss the appropriate timing for treatment due to anxiety about surgery. On the other hand, the satisfaction rate for treatment with the burrowing method is high at 91.2%, and it is evaluated as a treatment that meets the need to minimize scarring. Epidermoid cysts are a condition that can be completely cured with minimal scarring if treated appropriately and early. If you find a lump on your skin, we recommend consulting a dermatologist or plastic surgeon promptly without self-diagnosis.

Doctor's Comment | Dr. Kota Takakuwa, IC Clinic

Based on the experience of over 30,000 skin tumor surgeries by physicians supervised by our clinic, "early detection and early treatment" is the most crucial factor in minimizing scarring for epidermoid cysts. If left untreated, they will always grow larger, and if they become inflamed, treatment will become more complicated. "Waiting and seeing" is strictly forbidden for epidermoid cysts.

Epidermoid cysts are sac-like benign tumors that form under the skin. Because keratin and sebum continue to accumulate inside, they will absolutely never disappear on their own. They are sometimes confused with acne, but acne is an inflammation of the hair follicle that heals naturally, whereas epidermoid cysts cannot be cured unless the "sac" is removed.

The "burrowing method," which has become mainstream in recent years, is a surgical procedure where a small hole of about 4-6 mm is made in the center of the epidermoid cyst, the contents are expelled, and then the sac is removed. The traditional incision method required an incision 1-1.5 times the size of the cyst, but the burrowing method significantly reduces the scar size. It is a particularly effective option for epidermoid cysts in visible areas such as the face and neck.

However, the burrowing method is not applicable to all epidermoid cysts. If there is inflammation, if the cyst is very large, or if there has been repeated inflammation in the past, traditional incision methods or staged treatments may be necessary. Therefore, it is important to consult a medical institution that can provide appropriate diagnosis and surgical procedure selection.

Epidermoid cyst surgery is covered by insurance and can be performed for approximately 5,000 to 15,000 yen (depending on size and location) with a 30% co-payment. It is an outpatient procedure performed under local anesthesia, minimizing the burden on the body and impact on work.

[Evidence] The guidelines of the Japanese Dermatological Association also recommend surgical excision for the complete cure of epidermoid cysts. In the surgical experience of over 30,000 cases by physicians supervised by our clinic, the recurrence rate has been suppressed to less than 3% through appropriate procedure selection and complete excision. Numerous clinical reports show that the burrowing method, when performed by skilled physicians, can achieve a cure rate comparable to traditional methods.

Symptoms Suggesting an Epidermoid Cyst

- A round lump under the skin

- Slightly movable when pressed (mobile)

- A black dot (opening) may be visible in the center

- Gradually increasing in size

- Malodorous contents have been discharged

Signs Requiring Immediate Consultation

- Redness, swelling, and heat

- Increasing pain

- Rapid increase in size

- Discharge of pus

- Size of 1 cm or more

Points for Choosing a Medical Institution for Surgery

- Presence of physicians with extensive experience in skin tumor surgery

- Availability of the burrowing method

- Sufficient explanation before surgery

- Well-established post-operative follow-up system

Dr. Kota Takakuwa

With over 15 years of clinical experience and over 30,000 surgical cases in skin tumors and dermatological surgery, provides supervision based on medical evidence.

Specialties: Skin Tumors, Dermatological Surgery, Dermatology, Plastic Surgery

- Certified Miradry Physician

Clinical Achievements (as of 2024, cumulative)

- Skin Tumor/Dermatological Surgery: Over 30,000 cases

- Hyperhidrosis Treatment: Over 2,000 cases

- Rosacea/Facial Redness Treatment: Over 1,000 cases

Biography

- 2009: Graduated from the University of Tokyo, Faculty of Medicine

- 2009: Initial training at Tokyo Metropolitan Health and Medical Treatment Corporation Tokyo Metropolitan Health Medical Center

- 2012: Department of Dermatology, Tokyo Metropolitan Police Hospital

- 2012: Department of Dermatology, The University of Tokyo Hospital

- 2019: Treatment Director, IC Clinic

Supervised Areas: Skin tumors (moles, epidermoid cysts, lipomas, etc.), dermatological surgery, skin cancer, medical information related to general medical columns.

Frequently Asked Questions (Q&A)

Q1. Do epidermoid cysts heal on their own?

A. Epidermoid cysts absolutely do not heal on their own.

Epidermoid cysts have a structure where keratin and sebum continue to accumulate in a "sac" formed under the skin, and they cannot be cured unless the sac is removed. In this survey, 78.7% experienced leaving it untreated, and of those, 62.3% developed inflammation. The longer the delay, the larger the cyst becomes and the higher the risk of inflammation, so early consultation is recommended.

Q2. What happens if an epidermoid cyst is left untreated?

A. If left untreated, it gradually grows larger, and the risk of inflammation and infection increases.

In this survey, 62.3% of those who left it untreated experienced inflammation, and 5.0% experienced rupture. Inflamed epidermoid cysts cause severe pain and swelling, and often require a two-stage treatment: incision and drainage, followed by sac removal at a later date. Furthermore, repeated inflammation can cause adhesion to surrounding tissues, leading to larger scars.

Q3. What is the burrowing method for epidermoid cysts?

A. The burrowing method is a surgical procedure that minimizes scarring by making a small hole in the center of the epidermoid cyst to remove the sac.

The traditional incision method required an incision 1-1.5 times the size of the cyst, but the burrowing method only requires a hole of about 4-6 mm. In this survey, 91.2% of those who experienced the burrowing method responded that they were satisfied, with many comments stating, "the scar was smaller than I expected." However, it may not be suitable for inflamed or very large cysts, and a doctor's judgment is necessary.

Q4. Is epidermoid cyst surgery covered by insurance? Which department should I consult?

A. Epidermoid cyst surgery is covered by insurance. Please consult a dermatology or plastic surgery department.

Epidermoid cyst surgery is covered by health insurance, costing approximately 5,000 to 15,000 yen with a 30% co-payment (varies by size, location, and surgical method). In this survey, concerns about cost were relatively low at 10.7%, indicating good awareness of insurance coverage. You should consult a dermatology or plastic surgery department, especially one that offers day surgery.

Q5. When can I return to work after epidermoid cyst surgery?

A. With the burrowing method, desk work is possible from the next day.

In this survey, only a small percentage (5.3%) felt concerned about the "impact on work and daily life." With the burrowing method, downtime is about 2-3 days, and desk work is possible from the next day. However, for about a week after surgery, strenuous exercise and alcohol consumption should be avoided, and the wound should be kept clean. There are individual differences depending on the condition of the wound, so follow your doctor's instructions regarding post-operative life.

Risks of Leaving Untreated

- Gradual enlargement due to leaving it untreated, leading to larger surgical scars.

- Bacterial infection, leading to inflamed epidermoid cysts with severe pain and swelling.

- Repeated inflammation can cause adhesion to surrounding tissues, making surgery difficult.

- In rare cases, rupture can occur, spreading the contents to the surroundings and complicating treatment.

- In very rare cases, differentiation from malignant tumors may be necessary.

Who Should Consult Us | Consultation Guidelines

- If you find a round lump under your skin, consult promptly.

- If the lump becomes red, swollen, and painful, consult as soon as possible.

- If the lump reaches 1 cm or more in size, consult without delay.

- If the lump suddenly increases in size, consult immediately.

- If malodorous contents are discharged, consult urgently.

Clinic Information

Features of IC Clinic

- Staffed by a supervising physician with over 30,000 surgical cases in skin tumors and dermatological surgery.

- Offers minimally invasive surgery, including the burrowing method, to minimize scarring.

- Same-day and day surgery are available, making it convenient for busy individuals.

- Six branches in Shinjuku, Shibuya, Ueno, Ikebukuro, Tokyo, and Omiya offer services on weekends and holidays.

IC Clinic Shinjuku: 2F, Imas Aoi Bldg., 2-5-3 Yoyogi, Shibuya-ku, Tokyo

IC Clinic Shibuya: 5F, New Sansui Bldg., 3-16-2 Shibuya, Shibuya-ku, Tokyo

IC Clinic Ueno: 1F, Sankyu Bldg., 3-16-5 Higashi-Ueno, Taito-ku, Tokyo

IC Clinic Ikebukuro: 9F, Maeda Bldg., 2-15-3 Minami-Ikebukuro, Toshima-ku, Tokyo

IC Clinic Tokyo: 3F, Nihonbashi Front Bldg., 3-6-2 Nihonbashi, Chuo-ku, Tokyo

IC Clinic Omiya: B-ku, Fukubi Medical 2F, 1-60 Daimoncho, Omiya-ku, Saitama-shi, Saitama

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IC Clinic Shinjuku: Treatment for Epidermoid Cysts, Moles, Growths, Facial Redness, and Body Odor in Tokyo - Dermatology/Plastic Surgery

IC Clinic Shibuya: Treatment for Epidermoid Cysts, Moles, Growths, Facial Redness, and Body Odor in Tokyo

IC Clinic Ueno: Treatment for Epidermoid Cysts, Moles, Growths, Facial Redness, and Body Odor in Tokyo

IC Clinic Ikebukuro: Treatment for Epidermoid Cysts, Moles, Growths, Facial Redness, and Body Odor in Tokyo

IC Clinic Tokyo: Treatment for Epidermoid Cysts, Moles, Growths, Facial Redness, and Body Odor in Tokyo

IC Clinic Omiya: Treatment for Epidermoid Cysts, Moles, Growths, Facial Redness, and Body Odor in Saitama