Know this first
Skin lumps include sac-like cysts, lesions arising from fat or fibrous tissue, and lesions related to nerves, hair follicles, sweat glands or blood vessels. Epidermoid cysts, lipomas, dermatofibromas, pilomatricomas and neurofibromas are some examples. The type and depth help determine whether observation, removal or further testing is appropriate. Not every benign lesion needs surgery, and small lesions are not all removed in the same way. 13, 14
This guide focuses on common benign lesions and also introduces relatively rare lesions that are also identified in the treatment of skin nodules. Lesions that are not strictly tumors, such as cysts, hyperplasia, and post-traumatic changes, are also included in the ‘lump’ felt by the patient. The frequency of occurrence varies depending on age and area, and the order of the list is not in order of frequency or recommended surgery.
01. Lumps under the skin, are they all the same?
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The word ‘tumor’ refers to a condition in which tissue grows like a lump, and does not mean that it is cancer in itself. However, it cannot be concluded that all lumps that appear on the skin are benign. The features below are clues to help you understand, and are not criteria for confirming a diagnosis based on touch or photos alone. 3, 5, 6
| Which tissues or structures are involved? | Common lesions assessed | What to look for when deciding on treatment |
|---|---|---|
| sac-shaped cyst | Epidermoid cyst, hair cyst, dermoid cyst, multiple sebaceous cyst | Contents/pouch wall, inflammation, congenital location and depth |
| Fat and fibrous tissue | Lipoma, angiolipoma, dermatofibroma and acrochordon (skin tag) | Pain, growth, friction, observability, scarring after removal |
| tissue related to nerves | Neurofibroma, schwannoma, encapsulated neuroma, traumatic neuroma | Sensory symptoms, nerve connections, preoperative evaluation |
| Hair follicles, sweat glands, sebaceous glands | Pilomatricoma, trichoepithelioma, syringoma, poroma, nodular hidradenoma, eccrine spiradenoma, hidrocystoma and sebaceous hyperplasia | Origin, depth, and distinction from similar-appearing lesions |
| Blood vessels, surrounding blood vessels, or muscle components | Cherry hemangioma, pyogenic granuloma, glomus tumor, cutaneous leiomyoma | Reaction to bleeding, pain, temperature and location of occurrence |
| Skin surface/melanocytes | Seborrheic keratosis (age spots), intradermal nevus, etc. Melanocyte nevus (spot) | Change in color and shape, benignity, need for removal |
The characteristics and basis of each lesion are described in the corresponding section below. It includes lesions frequently encountered during medical treatment as well as relatively rare differential targets. Not all cysts are epidermoid cysts, and not all lumps related to nerves are the same ‘neuroma.’ 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25
What we see together in treatment
- When was it first discovered and how quickly did it grow?
- Is there pain, redness, discharge, or repeated bleeding?
- Does it feel connected to the skin or deep tissue?
- Did the same spot reappear after being squeezed or removed?
- Are surgical scars or keloids common?
02. If there are any changes, should I not postpone treatment?
Changes that require further evaluation
If an inexplicable lump continues to grow, feels like it is fixed deep in the area, or grows again in the area where it was removed, it is recommended to see a doctor. Depending on the size, depth, and examination findings, imaging tests such as ultrasound or MRI or referral to specialized treatment may be necessary. If malignancy is suspected, the order of examination and treatment is planned first. 6
These changes do not necessarily mean cancer. On the other hand, we do not judge it as benign just because it is small or not painful.
If you need immediate medical attention due to inflammation or wounds
If the red area spreads, pain or swelling worsens, or is accompanied by pus or fever, seek medical attention immediately. Lesions where the skin breaks down and bleeds repeatedly also need to be checked. Sticking yourself with needles or repeatedly squeezing can make the condition worse. 1, 2, 8, 9
03. Cysts: Epidermoid cysts and sac-shaped lesions that appear on the scalp, face, and body
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Why do epidermoid cysts come back even when squeezed?
This is because if only the contents come out and the pocket wall remains, it can fill up again.
Epidermoid cysts are lesions in which dead skin cells accumulate within the sac. When removal is necessary, aim to remove not only the contents but also the walls of the pouch. If it is a small lesion that does not cause any inconvenience and the diagnosis is clear, you can choose to observe its progress. 1
If the condition is red and painful, the timing of surgery may vary.
Not all swollen, red cysts are infected with bacteria. When the sac ruptures, the contents that come out can cause inflammation. Depending on the examination, you may consider controlling inflammation or drainage first and then removing the remaining cyst. Antibiotics are used to determine whether infection is present and are not necessary for all inflammatory cysts. 2
| therapy | target | Things to know |
|---|---|---|
| drainage | Treatment to reduce pain and swelling by removing stagnant contents | If pocket walls remain, they may reappear later. |
| cyst excision | Removal of lesions including the pouch wall | Incision and suturing methods vary depending on location, inflammation, and adhesions. |
Are smaller incisions always better?
For some noninfectious epidermoid cysts, small puncture removal techniques may help reduce wound length. However, the same method is not suitable for all sizes, locations, and inflammatory conditions. Studies comparing small incisions and conventional excisions have also been small in size, making it difficult to draw firm conclusions about differences in recurrence risk. 7
Rather than judging the appropriateness of surgery based solely on the size of the incision, it is necessary to check whether the lesion can be sufficiently identified and removed.
Are there any cysts other than epidermoid cysts?
| lesion | Features that aid understanding | What to look for in treatment |
|---|---|---|
| Hair cyst (pilar cyst) | Round, solid cysts commonly found on the scalp | Consider removal depending on discomfort, inflammation, or growth. Rapidly growing lesions should be re-evaluated |
| dermoid cyst | A lesion that contains skin components inside during its development. May appear around eyebrows, etc. | Depending on location, connections to deeper structures may need to be confirmed first |
| Multiple sebaceous cysts (steatocystoma multiplex) | Cysts associated with sebaceous gland ducts, which can occur in multiple numbers in the chest, armpits, etc. | Distinguish epidermoid cysts from ‘sebaceous cysts’, the common name for epidermoid cysts, and determine treatment range based on number and inflammation |
These three lesions do not occur with the same frequency. For dermoid cysts in particular, location and depth should be assessed before removal rather than assuming they are simple superficial lumps. 13, 20
04. Fat and fibrous tissue: What is the difference between lipoma and dermatofibroma?
Is it necessary to have a lipoma removed?
Lipomas with a clear diagnosis and no discomfort can be observed. If it is painful, grows, interferes with daily life such as moving or wearing clothes, or is bothering you about its appearance, you may consult for removal. 5
Lipoma is a benign tumor made up of fat cells. Although it is often relatively soft to the touch, it is not confirmed that it is a lipoma just by feeling it. Deep or large lesions or lesions with different growth patterns may require further evaluation. 5, 6
Before surgery, we check the depth as well as the size.
Removal methods vary depending on whether it is directly under the skin, close to the muscle, or in relation to nerves or surrounding tissue. Depending on the situation, imaging tests or collaboration with other departments or medical institutions may be necessary. 5, 6
Does a lipoma soon become a liposarcoma?
Normal lipomas are not expected to grow into liposarcoma. However, there may be other types of tumors that look similar to lipomas, so it is important to double-check the diagnosis for any lumps that change. 5
Is an angiolipoma the same as a lipoma?
Angiolipoma is a benign lesion with fatty components and small blood vessels. They can appear on the arms, etc. and may be painful when pressed or may be felt in multiple areas. Since it may be similar in appearance to a lipoma, it is not distinguished by pain alone and is confirmed by biopsy if necessary. 25
Why do dermatofibromas feel hard to the touch?
Dermatofibroma is a benign lesion related to fibrous tissue in the skin and can appear as a small, brown or skin-colored firm lump on the arms or legs. When you press lightly from both sides, the center may appear to go in, but this characteristic alone is not a self-diagnosis. 15
If the diagnosis is clear and there is no discomfort, it can usually be observed. After removal, the scar may be more noticeable than the original lesion, so the benefits of surgery and the scar must be weighed together. If it gets bigger, looser, or has a different shape, consider biopsy/excision to distinguish it from other lesions. 14, 15
Is skin tags also fibrous lesions?
Acrochordon is a common benign lesion that appears in a soft hanging shape on the neck, armpits, etc. It is different from a hard dermatofibroma. If you feel uncomfortable due to friction or are concerned about the appearance, you can consult for removal. If the appearance is not typical, check the diagnosis first. 13, 24
05. Nerve-related lumps: Are neurofibromas, schwannomas, and neuromas the same?
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Although they may occur in related tissues, they do not have the same diagnosis. It varies in appearance from small bumps on the skin to deep lumps connected to nerves. In cases where it is difficult to distinguish based on appearance alone, a pathological examination is helpful. 16, 17, 18, 19
| lesion | If you understand it easily | What to check |
|---|---|---|
| neurofibroma | Benign tumor that develops in the tissue surrounding the nerves | May appear as a soft, skin-colored bump. Consider observation or removal depending on inconvenience and diagnostic uncertainty |
| schwannoma | Tumors that arise from Schwann cells that surround nerves | Depending on the location, pain, numbness, and sensory changes may occur, so evaluate the relationship with the nerves. |
| Palisaded encapsulated neuroma (solitary circumscribed neuroma) | Benign neurogenic lesions that may appear as small skin-colored bumps on the face or back | It may look similar to a birthmark and can be distinguished by biopsy. |
| Traumatic neuroma | A reactive lump that can form during the nerve recovery process after an injury or surgery | Pressing may cause a tingling or persistent pain. Unlike general tumors, evaluated from the perspective of nerve damage and pain treatment |
Palisaded encapsulated neuroma and traumatic neuroma are differential diagnoses considered at particular sites or with certain symptoms; they do not explain every common skin lump. Despite its name, a traumatic neuroma is distinguished from a typical true tumor. 18, 19
Nerve connection or surgical plan may vary
If you experience an electric feeling when pressing, persistent tingling or loss of sensation, or changes in muscle strength, please let us know at the time of treatment. In particular, for lesions connected to major nerves, examination or specialized treatment may be planned first considering nerve function after removal. Traumatic neuromas are not simply resected, but are treated according to the symptoms and nerve condition. 17, 19
Just having one neurofibroma does not mean you have neurofibromatosis, which is a genetic disease. If multiple lesions or other features are present together, further evaluation is warranted. 16
06. Various nodules appear in hair follicles, sweat glands, blood vessels, and even on the skin surface.
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Pilomatricoma: a firm lump arising from hair-forming cells
Pilomatricoma is a benign tumor that may feel firm because of calcium deposits (calcification). It can occur on the face or neck of children and adolescents, but also in adults and at other sites. It is not caused by an insect bite. 3, 4
Since the appearance may be similar to other lumps, the diagnosis is confirmed with a biopsy. The general treatment is excision, and it is not a lesion that can be removed by squeezing like a pimple. For children, the timing of surgery, anesthesia, and treatment environment are determined based on age, location, and ability to cooperate. 3, 4
Other lesions related to hair follicles, sweat glands, and sebaceous glands
The hair follicles, sweat glands, and sebaceous glands from which hair grows are called ‘skin appendages.’ It includes relatively familiar lesions such as cystoma and sebaceous hyperplasia, as well as rare lesions such as follicular epithelioma and pore tumor. They are observed or removed depending on size, depth, and symptoms, and not all are subject to incision/suture surgery. 13, 21, 22
| lesion | Features that the general public should know | When deciding on treatment |
|---|---|---|
| Trichopithelioma | Small, skin-colored follicular tumors that appear on the face or back | Confirmation of diagnosis is a priority as it may be similar to other tumors. 22 |
| Syringoma | Several small hard bumps gathered around the eyes and back | Rather than considering multiple lesions to be operated on separately, the need for treatment and scarring are assessed together. 21 |
| Poroma | Bumps and nodules associated with sweat gland ducts appear on the hands and feet. | Observe bleeding, growth, and shape and check tissue if necessary 21 |
| nodular hidradenoma | May look like a hard lump or cyst in the skin | Differentiate from simple cyst and treat according to pathology results 21 |
| Eccrine spiraloma (spiradenoma) | A small lump in the skin that may be painful | Needs to be differentiated from painful cysts, etc. 21, 23 |
| Hidrocystoma | Small, clear cysts on the eyelids, etc. | Check and manage lesions around the eyes that are different from their location 20, 21 |
| Sebaceous hyperplasia | Small yellow or skin-colored bumps on the forehead, cheeks, etc. | The sebaceous glands are enlarged. Distinguish from other lesions if they are not typical 13, 24 |
Lesions related to blood vessel and muscle components
| lesion | Features that aid understanding | Important points in treatment |
|---|---|---|
| Cherry angioma | Small red bumps commonly seen in adults | It is typical and can be observed without discomfort. 13, 24 |
| pyogenic granuloma | Red bumps that grow relatively quickly and bleed easily | Contrary to its name, it is not a simple pus collection but a vascular lesion. Differentiating from other bleeding tumors 13, 14 |
| Glomus tumor | Severe pain or sensitivity to cold may appear at the fingertips or under the nails compared to their small size. | Assess the location and plan the necessary tests or surgery. Not all nail pain is caused by this lesion. 23 |
| Cutaneous leiomyoma | A hard nodule that arises from a small muscle component of the skin and may be painful. | Evaluation based on number, pain, and accompanying findings 23 |
Glomus tumors and cutaneous leiomyomas are not listed to mean that they are common lesions like cherry hemangioma. A relatively rare lesion that can be distinguished from a small but unusually painful lumpno see. You cannot determine benign or malignant based on pain alone. 6, 23
Lesions that rise on the surface of the skin, such as moles or age spots
- Melanocytic nevus, such as intradermal nevus: The mole may look like a skin-colored or brown thick lump. Check for new color, shape, and bleeding. 14, 24
- Seborrheic Keratosis: Commonly called age spots, they may appear thick or rough as if they are attached to the skin. Typical lesions can be observed, but if their appearance is irregular or changes rapidly, re-evaluate. 13, 24
These lesions may require a different surgical approach than resection of tumors deep in the skin. First, confirm the diagnosis and decide on a method based on symptoms, visual discomfort, and possibility of scarring.
A lump that may feel like a skin tumor but has a different origin
Ganglion of the wrist or mucocysts of the fingertips may involve structures around the joint. Distinguish it from a lump in the skin and plan treatment appropriate for its location. This list is a guide to understanding skin nodules and is not an exhaustive list of all rare tumors or pathological subtypes. 20
07. How are skin tumor surgery and biopsy performed?
- examination
- Anesthesia/Removal
- Pathological examination
- Check progress
Below is the general process. The actual possibility of surgery, examination and anesthesia methods, and number of visits vary depending on the condition of the lesion and treatment plan.
Step 1 · Examination and surgery plan
We check the time of occurrence, speed of change, symptoms, and previous treatment, and examine the extent of the lesion. For cases where the diagnosis is uncertain or for deep lesions, testing may be planned first. You will be explained why removal is necessary, the expected scar, and other options. 5, 6, 8
Please inform the medical staff of any medications you are taking, bleeding-related diseases, underlying diseases such as diabetes, allergies to anesthetics, disinfectants, or adhesives, and past scarring experiences. If you are taking medications that affect blood clotting Don't stop arbitrarily, Follow the instructions of the prescribing and operating staff. 8
Step 2 Anesthesia and lesion removal
Small, superficial lesions can be removed under local anesthesia. You may feel a stinging sensation during the anesthesia injection, and you may feel a pressing or pulling sensation during the surgery. If you feel pain, notify your healthcare provider. Check the lesion, remove it, stop the bleeding, and suture it if necessary. The way it progresses varies depending on the inflammation, location, and depth. 11, 12
Step 3 · Identify the required organization
A pathological examination identifies a lesion by examining the removed tissue under a microscope. It is not reserved for cases where cancer is strongly suspected. It can also be useful when a lesion resembles others, as with pilomatricoma, or when the suspected diagnosis is uncertain. 3, 11
Receive guidance on the test plan and how to check the results, and check whether additional treatment is needed depending on the results. Not all lesions require preoperative biopsy or MRI, and if there are suspicious findings, the order of examination and referral may be determined differently. 5, 6, 11
Step 4 · Check the wound and progress
Depending on the condition of the wound, you will be informed of the schedule for dressing, stitch removal, and return to daily life. Since the schedule varies depending on the surgical site and suturing method, there is no set schedule like ‘everyone will have stitches removed on the same day.’ 12
08. How are recovery, scars, and recurrence managed after surgery?
Until the wound heals
Keep the wound clean and protected in a guided manner. Do not pick off scabs or squeeze the wound. The timing of resuming washing your face, showering, and exercising varies depending on the area and the condition of the sutures. In particular, movements or friction that may cause wounds to open should be adjusted according to the medical staff's instructions. 9, 12
After the wound closes
Redness and tightness may change over time. Removing stitches does not immediately complete the scar. After the skin has healed, apply UV protection, and depending on the condition, you may be consulted about whether to use taping, silicone gel, or sheets. Silicone products should not be used arbitrarily on open wounds. 9, 10
Can scars remain?
Surgery that involves making incisions in the skin may leave scars. The appearance will vary depending on the size and location of the lesion, existing inflammation, the force pulling on the skin and the individual's recovery characteristics. If you have had keloids or thick scars in the past, please let us know before surgery. If the scar becomes thicker or itchy or painful, check the progress and determine necessary management. 8, 10
If I touch the same spot again
Epidermoid cysts can recur if the sac wall remains, and other tumors can recur depending on the extent and nature of the removal. Do not judge on your own whether the hardness you feel after surgery is a scar or a recurrent lesion, but check with your doctor. 1, 3, 5, 10
Signs you need to contact the hospital
- If bleeding continues or sudden swelling occurs even after pressure is applied
- If pain, redness, or heat becomes worse or pus or fever occurs
- If the wound opens or new paresthesia persists
If you have these symptoms, do not wait until your scheduled visit but contact the medical facility where you had your surgery. If bleeding is severe or your general condition is poor, prompt medical attention is required. 8, 9
Information on individual differences and side effects
After surgery, pain, swelling, bruising, bleeding, hematoma, infection, open wound, color change, scar, sensory change, and recurrence may occur. There are individual differences in the recovery period and results, and the risk of damage to surrounding nerves and tissues is also considered depending on the location and depth. 1, 5, 8
09. Frequently Asked Questions
In everyday life, epidermoid cysts are also called sebaceous cysts. The main content of an epidermoid cyst is keratin, and it is important to confirm the actual type of lesion during treatment. 1
If the diagnosis is clear and there are no symptoms, it can be observed. If it gets bigger, hurts, or causes inconvenience in your daily life, see your doctor again. 5
Light activities may be possible after minor surgery, but restrictions on work, exercise, and showering vary depending on the area and the state of the sutures. If your schedule is important, please let us know in advance at the time of treatment. 8
It is determined based on the examination results, need for testing, inflammatory status, and surgical schedule. Check whether surgery is possible and preparations before or during your visit.
It varies depending on the type, number, size, depth, location of the lesion, examination, and anesthesia method. It is accurate to be informed of the scope of treatment required and the estimated cost after a medical consultation. We do not guarantee insurance coverage or refund.
Good information to prepare before consultation
Organize a list of when it was first discovered, changes in size, pain or discharge, previous treatments, and medications taken. If you have old photos, it may be helpful to see changes. Please also tell us about your past surgeries, keloid experiences, and important schedules.
Check the lump in the skin, diagnosis, and treatment order.
After checking the type, location, depth of the lesion and the necessary tests, consult on the treatment direction. The actual possibility and method of surgery will be determined after a medical consultation.
Evidence and references
Data available: September 24–25, 2026. On September 25, we expanded the scope of diseases and related evidence. The information below is intended to help you understand the condition and treatment options, and does not mean that the lesions listed occur at the same frequency or that all require surgery. Study results may not apply equally to all patients.
- 1.British Association of Dermatologists. Cysts – epidermoid and pilar. Patient guidance from professional societies. Characteristics of epidermoid cysts and principles of observation and removal. View source
- 2.American Academy of Dermatology. Choosing wisely. Recommendation not to uniformly prescribe antibiotics for inflammatory epidermoid cysts. View source
- 3.Jones CD, et al. Pilomatrixoma: A Comprehensive Review of the Literature. Am J Dermatopathol. 2018;40(9):631–641. doi:10.1097/DAD.0000000000001118. Literature review of the characteristics, diagnosis and treatment of pilomatricoma. View source
- 4.British Association of Dermatologists. Pilomatricoma. Patient guidance from professional societies. View source
- 5.American Academy of Orthopaedic Surgeons. Lipoma and Atypical Lipomatous Tumors. Materials from professional societies explaining the observation, examination, and treatment of lipoma. View source
- 6.Hayes AJ, et al. UK guidelines for the management of soft tissue sarcomas. Br J Cancer. 2025;132:11–31. Published online 2024. doi:10.1038/s41416-024-02674-y. Guidelines for examination and professional evaluation of suspicious soft tissue masses. View source
- 7.Mukuda K, Watanabe J. Punch Incision versus Elliptical Excision for Epidermal Inclusion Cysts: Systematic Review and Meta-Analysis. Surgeries. 2021;2(3):335–346. doi:10.3390/surgeries2030033. Two randomized trials, analyzing a total of 100 people. Although differences in wound length have been reported in some non-infectious cysts, conclusions regarding recurrence are limited. View source
- 8.University Hospitals Sussex NHS Foundation Trust. Minor skin surgery (dermatology surgery). Guide to preparation, anesthesia, recovery, and side effects of skin surgery. View source
- 9.American Academy of Dermatology. Skin biopsy: Dermatologist-recommended wound care. Symptoms during recovery that require wound care and medical attention. View source
- 10.American Academy of Dermatology. Scars: Diagnosis and treatment. Principles of evaluation by scar type and management including silicone products. View source
- 11.American Academy of Dermatology. What is a skin biopsy? Purpose of biopsy and microscopic diagnostic process. View source
- 12.DermNet. Excision of skin lesions. Dermatological medical information regarding excision, suturing, and postoperative wound care. View source
- 13.Shen-Wagner J, Amidon J, Carek S. Diagnosing Common Benign Skin Tumors. Am Fam Physician. 2024;110(4):353–361. PMID 39418568. A clinical review on the differentiation and treatment selection of common benign skin lesions. View source
- 14.Trost JG, Applebaum DS, Orengo I. Common Adult Skin and Soft Tissue Lesions. Semin Plast Surg. 2016;30(3):98–107. doi:10.1055/s-0036-1584823. A review of common skin and soft tissue lesions in adults. View source
- 15.DermNet. Dermatofibroma. Characteristics of dermatofibromas, observation, and when to consider removal/biopsy. View source
- 16.DermNet. Solitary neurofibroma. Characteristics of solitary cutaneous neurofibroma and distinction between neurofibromatosis. View source
- 17.National Cancer Institute. Schwannoma. Schwannoma origins, symptoms and treatment options. View source
- 18.DermNet. Palisaded and encapsulated neuroma pathology. Pathology of encapsulated neuromas and differentiation between neurofibromas and schwannomas. View source
- 19.Yang H, et al. Traumatic neuromas of peripheral nerves: Diagnosis, management and future perspectives. Front Neurol. 2023;13:1039529. doi:10.3389/fneur.2022.1039529. A review of the diagnosis and treatment of traumatic neuroma. View source
- 20.DermNet. Cutaneous cysts and pseudocysts. Hair cysts, dermoid cysts, multiple sebaceous cysts and cystic lesions around joints, etc. View source
- 21.DermNet. Sweat gland lesions. Skin appendage lesions such as ductoma, pore tumor, hidradenoma, hidradenoma, and spiraloma. View source
- 22.DermNet. Trichoepithelioma. Characteristics and differentiation of follicular epithelioma. View source
- 23.Bhat MR, George AA, Jayaraman J. Painful tumors of the skin – from ENGLAND to LEND AN EGG to BLEND TAN EGG. Indian J Dermatol Venereol Leprol. 2019;85:231–234. doi:10.4103/ijdvl.IJDVL_1165_16. educational literature on painful lesions; Not a frequency ranking study. View source
- 24.DermNet. Common benign skin lesions. Information on general benign lesions such as skin surface, fibrous, and vascular lesions. View source
- 25.DermNet. Angiolipoma. Characteristics and histological identification of angiolipoma. View source
This page is general medical information and is not a substitute for an individual diagnosis. Depending on the results of the examination, the examination, surgery, and follow-up plan may vary.