Lumps Under the Skin: Cysts, Fatty Lumps, or Tumors — Do They Need to Be Removed?

Lumps Under the Skin: Cysts, Lipomas, or Tumors — Do They Need to Be Removed?

Many people may unexpectedly notice a small lump under the skin. These lumps can appear on the arms, back, shoulders, neck, scalp, trunk, or legs. Some feel soft and movable and cause no pain, while others may become firmer, grow larger, or start to hurt. Some may resemble a large clogged pore and repeatedly become inflamed or bothersome.

Common questions that immediately come to mind include:

• What is this lump?
• Is it a lipoma or a cyst?
• Could it be cancer?
• Does it need to be removed?

The reassuring news is that many lumps found under the skin are benign conditions such as lipomas or cysts and are not cancer. However, “many” does not mean “all.” Some lumps may be tumors that require further investigation, and in uncommon cases they may represent a malignant soft-tissue tumor that should not be overlooked.

Therefore, the important point is not to panic whenever you find a lump, but to understand which lumps may be monitored, which should be medically evaluated, and which may need removal or biopsy.

What is a lump under the skin? A lump under the skin may arise from the skin, subcutaneous fat, or deeper soft tissues. Possible causes include:

• Lipoma
• Epidermal inclusion cyst
• Abscess or inflammatory/infected lump
• Enlarged lymph node
• Fibrous tissue or a lump related to previous injury
• Vascular lesions or abnormal blood vessels
• Soft-tissue tumors

Malignant tumors such as soft tissue sarcoma are uncommon, but certain features require particular attention. Appearance alone may provide some clues but cannot always establish a diagnosis, especially when a lump is deep, rapidly growing, or has unclear characteristics.

What is a Lipoma like?
A lipoma is a benign tumor composed of fat cells and commonly develops beneath the skin. It is frequently found on the back, shoulders, upper arms, thighs, neck, or abdomen. Common characteristics include:

• Soft consistency
• Relatively smooth borders
• Slightly movable under the skin
• Slow-growing
• Usually painless
• The skin over the lump usually appears normal
• Some people may have more than one lipoma

Most lipomas are harmless and do not necessarily need to be removed if they are small, painless, slow-growing, and do not interfere with daily life. However, some lumps should be evaluated further, particularly if they are large, rapidly growing, deep, unusually firm, painful, or causing numbness, radiating pain, or movement problems due to pressure on nearby structures. Such a lump may not always be a simple lipoma.

What is an Epidermal Inclusion Cyst like?
An epidermal inclusion cyst is a sac beneath the skin containing keratin and skin-cell material. It usually appears as a round lump and may have a small central opening or dark spot known as a punctum.

• Common characteristics include:
• A round lump beneath the skin
• Usually firmer than a lipoma
• May move slightly
• Usually grows slowly
• May have a small central opening
• If inflamed, it may become swollen, red, painful, and warm
• Some cysts may discharge thick whitish material with an unpleasant odor

A cyst that is not inflamed and does not cause problems may not need immediate removal. Removal may be considered if it becomes larger, painful, repeatedly inflamed or infected, ruptures, drains pus, or is located where repeated friction causes irritation, such as the back, neck, armpit, or groin.

An important consideration is that if a cyst is severely inflamed or has developed into an abscess, the doctor may need to drain the collection or treat the inflammation first. Definitive removal of the cyst wall may then be scheduled when the inflammation has settled, because excision during marked inflammation can be technically more difficult and may increase the risk of wound problems or recurrence.

How is an abscess or inflamed lump different from a cyst or lipoma? An inflamed lump or abscess usually has more obvious symptoms, such as:

• Pain
• Swelling, redness, and warmth
• Tenderness
• Rapid enlargement over several days
• Pus may be present, sometimes accompanied by fever
• The surrounding skin may become tense or increasingly red

An abscess should not be squeezed or punctured at home because this may worsen the infection, cause deeper tissue involvement, or increase scarring. If the area is painful, swollen, red, or appears to contain pus, a doctor should evaluate whether drainage, antibiotics, or further investigation is appropriate.

Which lumps under the skin are more likely to be benign? Lumps with reassuring characteristics often include the following:

• Small size
• Very slow growth or little change over time
• Movable
• Soft or elastic
• Painless
• Normal-looking skin over the lump
• No fever, unexplained weight loss, or other concerning symptoms
• Present for a long time without significant change

However, even when a lump appears harmless, anyone who is uncertain should consider seeing a doctor for confirmation. Deep lumps or newly enlarging lumps can sometimes be difficult to assess by self-examination alone.

Warning signs that should be evaluated by a doctor You should seek medical evaluation rather than simply observing the lump if it has any of the following characteristics:

• Rapid growth
• Size greater than approximately 5 centimeters, or about the size of a golf ball or larger
• Located deep beneath the skin, poorly mobile, or seemingly attached to underlying tissue
• Unusually firm or hard
• Pain not explained by an injury
• Skin over the lump changes color, becomes red, ulcerates, or bleeds
• The lump returns after previous removal
• Multiple lumps associated with other abnormal symptoms
• Fever, unexplained weight loss, night sweats, or unusual fatigue
• Pressure on a nerve causing numbness, weakness, or radiating pain
• A lump in the neck, armpit, or groin that may represent an enlarged lymph node
• A breast lump, testicular lump, or lump involving another important anatomical area

In particular, a lump that continues to grow, is large, deep, or painful should be evaluated before deciding on removal. In surgery, certain suspicious masses require careful planning because an unplanned excision can complicate subsequent treatment if the mass turns out to be malignant. Does every lump need to be removed? The answer is “No, not every lump needs to be removed.”

The decision depends on several factors including what the lump is and:

• Whether it causes symptoms
• Whether it is growing or remains stable
• Whether its location interferes with normal activities
• Whether there is a risk of inflammation, infection, or recurrence
• Whether it has features suspicious for a tumor or malignancy
• How much it affects appearance or causes concern for the patient

Cases that may be suitable for observation

• A small lipoma
• Slow-growing
• Painless
• Movable
• No suspicious features
• Does not interfere with daily life

In these situations, the doctor may recommend monitoring the size and any changes and returning for reassessment if the lump grows or develops symptoms.

Cases in which removal may be considered

• The lump is painful or tender
• The lump is increasing in size
• The lump is in an area exposed to repeated friction
• A cyst becomes repeatedly inflamed
• The lump interferes with movement
• The lump compresses a nerve
• The lump causes significant concern or affects confidence
• The doctor recommends tissue examination to establish the diagnosis
• Situations in which routine excision should not be performed without further evaluation

If a lump has suspicious features—for example, it is larger than about 5 centimeters, rapidly growing, deep, unusually firm, fixed, or painful—appropriate imaging such as ultrasound or MRI may be required before removal, depending on its characteristics and location. A suspicious soft-tissue mass should not simply be excised as though it were an ordinary benign lump because, if it is malignant, biopsy planning, incision placement, and the initial surgical approach can affect subsequent treatment.

How do doctors diagnose a lump under the skin? Evaluation begins with a detailed medical history and physical examination. The doctor may ask:

• How long has the lump been present?
• Is it growing rapidly?
• Is it painful?
• Has it ever become inflamed, red, or drained pus? Has it previously been removed and then returned?
• Was there any previous injury to the area?
• Are there fever, weight loss, or other unusual symptoms?
• Is there a previous history of cancer?

The doctor will then examine characteristics such as size, location, depth, consistency, and mobility, its relationship with the skin and underlying muscles, and whether the overlying skin has an opening, ulceration, redness, or color change.

Ultrasound
Ultrasound is commonly used to evaluate superficial soft-tissue lumps. It can help determine whether a lesion is cystic or solid and assess features suggesting a lipoma, abscess, or vascular involvement. It does not use ionizing radiation and is particularly useful for superficial lesions.

MRI
MRI can be particularly useful for deep or large masses, lesions close to muscles, nerves, or blood vessels, and masses with suspicious features. It helps define the extent of a lesion, its relationship to surrounding structures, and can assist with planning biopsy or surgery.

Biopsy or pathological examination
When a lump is removed, the specimen is often sent for pathological examination when clinically appropriate to confirm the diagnosis, because appearance alone cannot always establish exactly what type of lump it is. For a mass suspected to be malignant, biopsy may need to be carefully planned before definitive surgery by the appropriate specialist team so that subsequent treatment is not compromised.

How is a lump under the skin removed?
If the doctor determines that a lump is suitable for removal, a small, superficial, uncomplicated lesion can often be removed as a minor surgical procedure, sometimes under local anesthesia. The general steps may include:

• Cleaning the skin around the surgical area
• Administering local anesthesia
• Making an appropriately positioned incision
• Removing the lump or, in the case of a cyst, removing the cyst wall as completely as feasible
• Controlling bleeding
• Closing the wound with sutures when appropriate
• Sending the specimen for pathological examination when appropriate
• Scheduling wound review and suture removal when needed

For cysts, complete removal of the cyst wall, when feasible, helps reduce the chance of recurrence. Lipomas should also be removed carefully, particularly when located near nerves or blood vessels. Large, deep, or anatomically complex masses may require surgery in an operating room and imaging before treatment planning. What happens if the lump is not removed? If a lipoma or cyst causes no symptoms and a doctor has assessed it as having no suspicious features, observation may be an appropriate option. Changes to monitor include:

• Whether the lump is getting larger
• Whether it becomes painful
• Whether the overlying skin changes color
• Whether numbness, radiating pain, or weakness develops
• Whether the lump becomes inflamed, swollen, red, or drains pus

If any changes occur, the lump should be reassessed by a doctor. How can you tell a benign lump from cancer? Most lumps beneath the skin are not cancer, but some malignant or soft-tissue tumors can initially appear as a painless lump that gradually enlarges. Features that warrant further evaluation include:

• Continued growth
• Large size
• Deep location beneath the fatty layer or close to muscle
• Hard or fixed consistency
• Pain or tenderness
• Recurrence after previous removal
• Changes in the skin over the lump
• Systemic symptoms such as unexplained weight loss, fever, or night sweats

If these features are present, systematic evaluation is appropriate. A suspicious mass should not simply be removed as an ordinary lump without proper planning, because correct initial assessment and management are particularly important if the lesion proves to be malignant.

Which locations require particular attention?
A lump in the neck may represent a cyst, enlarged lymph node, thyroid nodule, salivary-gland mass, or another condition. Evaluation is particularly important if the lump continues to enlarge, feels hard or fixed, or is accompanied by persistent hoarseness, difficulty swallowing, unexplained weight loss, or prolonged fever.

• A lump in the armpit or groin may represent an enlarged lymph node, cyst, abscess, or skin-related lesion. A persistent, enlarging, or significantly painful lump should be evaluated.
• A breast lump should not automatically be assumed to be a lipoma or cyst. Medical assessment and appropriate breast imaging may be recommended according to age, clinical findings, and individual risk.
• A testicular lump should be medically evaluated. Assessment generally requires a specific examination and often ultrasound rather than simply observing it at home.
• A lump deep within a muscle may require imaging before deciding on treatment because a deep mass may not be a simple subcutaneous lump.

What should you do if you discover a lump under your skin? Consider the following:

• Do not squeeze, press, or puncture the lump yourself
• Monitor its size; taking a photograph or recording the date it was first noticed may help
• Watch for rapid growth, pain, redness, or pus
• Avoid vigorous massage over the lump
• If the area is exposed to friction, try to reduce repeated pressure
• If it becomes inflamed, red, warm, or painful, seek medical evaluation
• If the lump enlarges or you are uncertain about it, have it medically assessed

Evaluation while a lump is still small and not inflamed can sometimes make assessment and treatment more straightforward. The appropriate procedure and wound size, however, depend on the type, size, depth, and location of the lump.

Frequently Asked Questions
1. Does every lipoma need to be removed?
No. If a lipoma is small, painless, slow-growing, movable, and assessed by a doctor as having typical benign characteristics, it may simply be monitored. If it enlarges, becomes painful, is large or deep, or interferes with function, further evaluation or removal may be considered.

2. Can I squeeze an epidermal cyst myself?
This is not recommended. Squeezing can rupture the cyst beneath the skin and lead to inflammation, infection, or increased scarring. If the cyst becomes inflamed or contains pus, it should be assessed and treated appropriately by a doctor.

3. Can a cyst return after removal?
Yes. Recurrence can occur, particularly if part of the cyst wall remains. Significant previous inflammation may also make complete removal more difficult. When appropriate, definitive excision is often easier after acute inflammation has settled.

4. Which lumps under the skin are concerning?
A rapidly growing lump, a mass larger than approximately 5 centimeters, a deep, hard or fixed mass, pain, changes in the overlying skin, or recurrence after previous removal should be medically evaluated.

5. Does every lump need an ultrasound?
Not necessarily. If clinical examination strongly suggests a benign superficial lesion with no concerning features, imaging may not always be required. If the diagnosis is uncertain, the mass is deep or rapidly growing, or another condition is suspected, ultrasound or MRI may help with further evaluation.

6. Does removing a lump under the skin hurt?
Small superficial lumps can often be removed under local anesthesia. During the procedure, pain is usually minimized by the anesthetic, although pressure or pulling sensations may still be felt. Mild discomfort or tightness can occur afterward, and wound care should follow the doctor’s instructions.

7. Does every removed lump need pathological examination?
The decision depends on the clinical situation, but removed tissue is commonly sent for pathological examination to confirm the diagnosis, particularly when a lump is enlarging, its diagnosis is uncertain, or it has unusual characteristics.

     Lumps under the skin are common, and many are caused by benign conditions such as lipomas or cysts. Nevertheless, proper assessment is important because some masses may not be simple benign lumps and may require further investigation before treatment is planned.

Not every lump needs to be removed. A small, slow-growing, painless lump without suspicious characteristics may be monitored. However, a lump that is rapidly growing, large, deep, painful, hard, fixed, repeatedly inflamed or interfering with daily activities should be evaluated by a doctor. Removal is not performed only for cosmetic reasons or reassurance; in some cases, it can help establish a diagnosis or treat recurrent symptoms. If you discover a lump under the skin and are unsure whether it is a cyst, lipoma, or another type of tumor, medical evaluation can help determine the appropriate next step.

For information and appointments
Sapiens Hospital “Move Better : Live Better”
Tel. 02-111-3703 

References
1. Achar S, Yamanaka J, Oberstar J. Soft Tissue Masses: Evaluation and Treatment. American Family Physician. 2022;105(6):602–612.
2. Garner HW, et al. ACR Appropriateness Criteria® Soft Tissue Masses: 2022 Update. Journal of the American College of Radiology. 2023.
3. National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NICE Guideline NG12. Updated guidance.
4. Hayes AJ, et al. UK guidelines for the management of soft tissue sarcomas. British Journal of Cancer.2025.
5. Dangoor A, et al. UK guidelines for the management of soft tissue sarcomas. Clinical Sarcoma Research. 2016;6:20.
6. Higgins JC, Maher MH, Douglas MS. Diagnosing Common Benign Skin Tumors. American Family Physician. 2015;92(7):601–607.7. Weir CB, St.Hilaire NJ. Epidermal Inclusion Cyst. StatPearls Publishing. Updated 2023.
8. Salam GA. Lipoma Excision. American Family Physician. 2002;65(5):901–904.