Most lumps and swellings under the skin are harmless and can be left alone. However, see your GP if you develop a new lump or swelling so that the cause can be identified. A painful lump or swelling that appears suddenly over a day or two may be caused by an injury or infection. It's likely to be an infection if the skin around the lump is red and warm. Your GP can advise you about how to care for this.
(3) Neurogenic tumour
(5) Myositis ossificans
(6) Glomus tumour
(8) Non-tumour conditions that can cause lumps and bumps
(9) Ganglion cysts
(10) Epidermoid and pilar cysts
Chronic inflammation or granulomatous lesions Benign soft tissue tumours are lumps and bumps that are non-cancerous. Soft tissue is defined as the supportive or connective tissue of the body and includes fibrous connective tissue, bone, muscle, fat, blood/lymph vessels and the nervous system
A lipoma is a benign tumour composed of fatty tissue. It is the most common benign soft tissue tumour and occurs in at least 1% of the population. The symptoms of a lipoma are usually a painless, slowly growing mass which is mobile and has a soft consistency on examination. Most lipomas occur in the superficial soft tissues but benign lipomas can occur deep to the connective tissue or intramuscular areas. Treatment of a simple lipoma is usually removal either because it is causing pressure on surrounding structures or for cosmetic reasons. The possibility of a lipoma recurring is expected to be less than 5%; however, the recurrence rate can increase substantially with large deep-seated lipomas that infiltrate muscle.
Fibromatosis are rare benign tumours that have a propensity for locally aggressive behaviour and
for invading surrounding structures but they do not have the potential to spread to other parts of
the body. They can be painful. Fibromatosis can occur anywhere in the body, but most commonly
affect three locations. Firstly the limb and limb girdle (shoulders, hips, buttocks), secondly the
abdominal wall (most commonly in women and closely associated with a recent pregnancy) and
lastly within the abdomen arising from the bowel wall.
Fibromatosis of the limbs and limb girdle have a high local recurrence rate after complete surgical removal ranging from 24% to 77%. Abdominal wall tumours mostly occur in female patients and usually develop during or soon after pregnancy and can also develop in the scar from a caesarean section. In marked contrast to limb or limb girdle fibromatosis, tumours isolated to the abdominal wall very rarely recur after surgical removal.
Treatment is best performed in the context of a specialist multidisciplinary team (to contact the specialist clinic), and as with other soft tissue tumours diagnosis is established by core needle biopsy. Most are slow-growing but some can behave aggressively. Surgical removal with clear margins is the standard treatment, but observation does also have a role in some cases. For recurrent fibromatosis after previous surgical removal, further surgery with radiotherapy or systemic therapy (anti-inflammatory drugs, chemotherapy, or hormonal treatment) may be required.
Dermatofibroma are common benign skin tumours that cause lumps in the skin and frequently cause concern upon discovery. The causes of dermatofibroma may include a reaction to trauma such as insect bites but the precise cause is often unclear. They occur more frequently in women than men, most commonly in young adulthood. Usually a single nodule develops on an extremity, most commonly the lower legs, but lesions can occur at any skin site and individuals may have several lesions. Removal and biopsy is usually performed when uncertainty remains after an initial clinical examination.
Epidermoid and pilar cysts are small smooth cystic lumps under the skin surface (also called sebaceous cysts or trichilemmal cyst) and they represent the most common skin cysts. While they may occur anywhere on the body, they occur most frequently on the scalp, neck, face and trunk. Epidermoid cysts are usually slow-growing and symptomless although discharge of a foul-smelling material sometimes occurs. The cysts can become inflamed or infected, resulting in pain and tenderness. Surgical removal of a sebaceous cyst is a simple procedure and can often be performed under local anaesthetic.
A haematoma occurs when blood leaks outside the blood vessels and it can follow an injury or be spontaneous. Causes for the latter include a systemic bleeding predisposition (including anticoagulation therapy). Importantly, bleeding into a pre-existing soft tissue tumour has to be considered. A previous injury is often forgotten. Haematomas may mimic tumours by continuing to expand. Diagnosis can be accomplished by clinical history, imaging and core needle biopsy.
An abscess can often cause a painful soft tissue lump. An abscess is caused by an infection that results in a collection of pus within inflamed tissues. Treatment includes drainage and antibiotics.