Lump under the skin

The key answer

A lump under the skin is most often benign, but it cannot be reliably assessed only by touch or a photo. A soft, slowly growing, movable lump may be a lipoma. A round lesion with a small central point or occasional discharge may suggest an epidermoid cyst. A painful, red, warm and enlarging lump may be an abscess. A hard, rapidly growing, fixed, ulcerated, bleeding, larger, deeper lesion or one that persists over time requires medical diagnosis. Sometimes dermoscopy, ultrasound, biopsy, lesion removal and histopathological examination are needed.

What can a lump under the skin mean?

Patients often say: “I have a small ball under the skin”, “I can feel a lump”, “something has grown”, “it is probably a lipoma” or “it is probably a cyst”. Many such lesions are indeed benign, but there are several possible causes and they require different management.

Some lumps may be observed, others are removed electively, and others — especially painful, inflamed or oncologically suspicious lesions — require faster diagnosis. The first step is assessment: location, size, growth rate, pain, mobility, skin appearance and accompanying symptoms.

Common causes of a lump under the skin

1. Lipoma

A lipoma is usually a soft, elastic, slowly growing lump made of fat tissue. It is often movable under the fingers and painless. It may appear on the trunk, limbs, neck, back or other areas. Lipomas are usually benign, but if a lump grows quickly, hurts, is deep, large or atypical, it needs further diagnosis.

2. Epidermoid cyst / “sebaceous cyst”

An epidermoid cyst, often called a “sebaceous cyst”, may look like a round lump under the skin. Sometimes a small point is visible in the centre, and thick, unpleasant-smelling material may come out of the lesion. A cyst may become inflamed, enlarge, hurt and recur, especially if it has been squeezed or has not been removed completely.

3. Skin abscess

An abscess is a pocket of pus caused by infection. It is usually painful, red, warm, tense and may enlarge quickly. Sometimes fever, malaise or purulent discharge occur. An abscess should not be squeezed. Treatment may require incision and drainage, dressings and sometimes antibiotics — the decision is made by a doctor.

4. Fibroma or another benign skin lesion

Some lumps are benign lesions of the skin or subcutaneous tissue, such as fibromas, warts, post-traumatic or scar-like lesions. They are often removed if they bother the patient, catch on clothing, are mechanically irritated or raise diagnostic doubts.

5. Enlarged lymph node

A lump in the neck, armpit, groin or under the jaw may be an enlarged lymph node. This often occurs after infection, skin inflammation, trauma or systemic disease. If the node is hard, painless, enlarging, persistent or accompanied by general symptoms, medical diagnosis is needed.

6. Skin or subcutaneous tumour

Less commonly, a lump may be a tumour of the skin, subcutaneous tissue or a skin metastasis. Rapid growth, hardness, fixation to deeper tissues, ulceration, bleeding, a non-healing wound, skin colour change, irregular shape or increasing pain are particularly concerning.

Red flags — when should you not wait?

Not every lump requires urgent intervention, but there are situations in which a visit should not be delayed. The goal is to rule out infection, abscess, a lesion requiring biopsy or cancer.

Does a lump under the skin need to be removed?

Not always. The decision depends on the diagnosis, size, location, symptoms, growth rate and patient expectations. Some lipomas may be observed if they are small, stable and painless. Cysts are often removed if they grow, recur, become inflamed or bother the patient. Abscesses require treatment of inflammation, sometimes incision and drainage. Suspicious lesions should be removed or biopsied in a way that allows histopathological examination.

What does diagnosis involve?

Diagnosis begins with a conversation and examination. The doctor assesses how long the lump has been present, whether it is growing, painful, changing the skin, whether it has been squeezed, whether there are signs of infection and whether the patient has chronic diseases. Sometimes clinical assessment is enough to plan treatment, but some lesions require additional steps.

Possible diagnostic steps

• palpation and assessment of the skin over the lump,
• dermoscopy if the lesion is on the skin or pigmented,
• soft tissue ultrasound if the lump is deeper, larger or unclear,
• incision and drainage if an abscess is suspected,
• biopsy if the diagnosis is uncertain,
• surgical removal with histopathology if indicated.

Lump under the skin — surgeon or dermatologist?

If the lesion is superficial, pigmented, resembles a mole, wart, patch or has a suspicious skin appearance, a dermatologist and dermoscopy are a good first step. If the lump is palpable under the skin, growing, painful, looks like a lipoma, cyst or requires removal, a surgeon is usually the right pathway.

In practice, these pathways often complement each other. A dermatologist helps assess skin and pigmented lesions, while a surgeon qualifies patients for removal, biopsy, abscess drainage or histopathological examination.

What should you not do with a lump under the skin?

• do not squeeze a cyst or abscess by force,
• do not puncture the lump yourself with a needle,
• do not apply aggressive “wart” preparations without a diagnosis,
• do not heat a painful red lesion without medical advice,
• do not delay the visit if the lump grows quickly, bleeds or is hard and fixed,
• do not assume that every soft lump is definitely a lipoma,
• do not remove a lesion with a tissue-destroying method if histopathology may be needed.

How to prepare for the consultation?

• think about when the lump first became noticeable,
• check whether it is growing and how quickly,
• tell the doctor whether it hurts, itches, cracks, bleeds or oozes,
• do not squeeze the lesion before the visit,
• bring previous ultrasound, biopsy or histopathology results if you have them,
• inform the doctor about diabetes, reduced immunity, blood thinners, allergies and previous cancers,
• take a dated photo if the lump is visibly changing.

Patient pathway: from lump under the skin to diagnosis

This page helps choose the right direction. It does not replace procedure pages; it guides the patient to consultation, biopsy, dermoscopy, abscess incision or lesion removal.

Doctors diagnosing and treating lumps under the skin

Can you feel a lump under the skin?

Do not squeeze or puncture the lesion yourself. Book a consultation — the doctor will assess whether it is a lipoma, cyst, abscess, skin lesion, lymph node or a lump requiring biopsy or histopathology.

Frequently asked questions about lumps under the skin

Read more — lumps, skin lesions, biopsy and removal

• Skin lesion removal
• Lesion removal with histopathology
• Surgical skin biopsy
• Dermoscopy
• Dermatology consultation
• Surgery
• Piotr Rak, MD, PhD
• Iwona Chruścicka, MD, PhD
• Katarzyna Przekazińska-Boager, MD

Book a consultation — a lump under the skin is not always “just a lipoma”

The doctor will assess the lesion and decide whether observation, dermoscopy, inflammation treatment, biopsy, abscess incision or removal with histopathology is needed.