Benign soft tissue tumours and other lumps and bumps

Contents

• Lipomas
• Haemangioma
• Neurogenic tumour
• Fibromatosis
• Myositis ossificans
• Glomus tumour
• Dermatofibroma
• Non-tumour conditions that can cause lumps and bumps
  • Ganglion cysts
  • Epidermoid and pilar cysts
  • Haematomas
  • Abscesses
  • Chronic inflammation or granulomatous lesions

Benign soft tissueA group of cells with a similar structure and a specialised function. tumours are lumps and bumps that are non-cancerousMalignant, a tumour that may invade surrounding tissues or spread to distant parts of the body.. Soft tissue is defined as the supportive or connective tissueA type of tissue made up of fibres forming a framework and support structure for body tissues and organs. of the body and includes fibrous connective tissue, bone, muscleTissue made up of cells that can contract to bring about movement., fatOne of the three main food constituents (with carbohydrate and protein), and the main form in which energy is stored in the body., bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid./lymphA watery or milky bodily fluid containing lymphocytes, proteins and fats. Lymph accumulates outside the blood vessels in the intercellular spaces of the body tiisues and is collected by the vessels of the lymphatic system. vessels and the nervous systemThe network of nerves, which are bundles of nerve fibres carrying information in the form of electrical impulses.. All lumps are usually referred to as tumours whether they are benignNot dangerous, usually applied to a tumour that is not malignant. or malignantDescribes a tumour resulting from uncontrolled cell division that can invade other tissues and may spread to distant parts of the body.. Benign soft tissue tumours are relatively common in the general population. Benign tumours cannot spread to other parts of the body but they can continue to grow at the original site where they can cause a problem by pressing on the surrounding organs. They can also be cosmetically unsightly. There are a number of different types of benign soft tissue tumour that I will explain below.

Lipomas

A lipoma is a benign tumourAn abnormal swelling that is not cancerous; in other words, it does not invade local tissues or spread to distant parts of the body. 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. 

Haemangioma

Haemangioma is the most frequently encountered soft tissue tumour of the blood vessel system and accounts for approximately 7% of all benign soft tissue tumours. Infantile haemangiomas are present at or around birth and are commonly recognised birthmarks. Intramuscular haemangiomas are a less common variant which often occur during teenage or adult life. The lower extremity is the most common location for intramuscular haemangiomas. They constitute the most common benign tumour in the skeletal muscles. MRIAn abbreviation for magnetic resonance imaging, a technique for imaging the body that uses electromagnetic waves and a strong magnetic field. can be very helpful in the diagnosisThe process of determining which condition a patient may have. of intramuscular haemangioma. Treatment can include simple re-assurance when they cause no or little symptoms. For lesions that cause symptoms surgical removal or embolisation (where the feeding blood vessels are selectively blocked through a catheterA tube used either to drain fluid from the body or to introduce fluid into the body. introduced under X-rayA type of electromagnetic radiation used to produce images of the body. guidance) can be considered.

Neurogenic tumour 

Benign peripheral nerveBundle of fibres that carries information in the form of electrical impulses. sheath tumours (PNST) are soft tissue neoplasms that develop from a nerve and subtypes include schwannomas and neurofibromas. Benign schwannoma is the most common tumour originating from peripheral nervesBundles of fibres that carry information in the form of electrical impulses.. Benign PNST can occur sporadically or as manifestations of geneticRelating to the genes, the basic units of genetic material. syndromes such as neurofibromatosisAn uncommon inherited disorder characterised by numerous, soft, fibrous swellings that grow from nerves, and by cafe au lait spots on the skin. (NF) types 1 and 2. Schwannomas can develop in any nerve trunk in the entire body but are most commonly found in cranial nerves and in the peripheral nerves of the upper limb. Approximately 3% occurs in the abdomenThe part of the body that contains the stomach, intestines, liver, gallbladder and other organs.. The clinical sign of a schwannoma arising within a nerve trunk of the upper or lower limb is often typical. Patients have a swelling which is painful to pressure; the tumour is mobile from side to side, but not in the vertical axis of the limb (selective mobility). Tapping on the lump can induce a painful prickling or tingling sensation in the area of the nerve. 

MR imaging is very helpful and can show a well-defined mass in relation to a nerve. A biopsyThe removal of a small sample of cells or tissue so that it may be examined under a microscope. The term may also refer to the tissue sample itself. may be required if the diagnosis is in doubt after both a clinical examination and imaging, but this unfortunately can be very painful.

Benign schwannomas are best treated by marginal excisionThe removal of a piece of tissue or an organ from the body. with nerve preservation if they become symptomatic or cause cosmetic embarrassment. These encapsulated neoplasms are located within the nerve and do not invade the nerve fibres. This allows marginal excision of the tumour whilst at the same time preserving the nerve involved.

Fibromatosis

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 abdominalRelating to the abdomen, which is the region of the body between the chest and the pelvis. wall (most commonly in women and closely associated with a recent pregnancythe period from conception to birth) and lastly within the abdomen arising from the bowelA common name for the large and/or small intestines. 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 multidisciplinaryRelating to a group of healthcare professionals with different areas of specialisation. team, 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 radiotherapyThe treatment of disease using radiation. or systemicAffecting the whole body. therapy (anti-inflammatoryAny drug that suppresses inflammation drugs, chemotherapyThe use of chemical substances to treat disease, particularly cancer., or hormonal treatment) may be required.

Myositis ossificans

Myositis ossificans is a benign condition of bone formation. More than half of these cases develop after a traumatic event. Myositis ossificans occurs most commonly in the second and third decades of life and usually in extremities exposed to previous trauma such as blunt muscular trauma (contusion, muscular tears and strains). Symptoms often include pain, a palpable lump and muscle contractures with a decreased range of motion. Myositis ossificans frequently reabsorbs spontaneously and removal should only be carried out in patients with significant symptoms (continued pain, limited motion, or deterioration of function with matured ectopicDisplaced from its normal position in the body. Also used to refer to ectopic heartbeats. bone) after a period of conservative treatment.

Glomus tumour

Glomus tumours are benign tumours mostly located in the hands and they can cause severe joint tenderness and pain. Most glomus tumours occur in the nail-base.

Dermatofibroma

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.

Non-tumour conditions that can cause lumps and bumps

Ganglion cysts

A ganglion cyst is a swelling that often appears on or around joints and tendons in the wrist, hand or foot.  They are the most usual cause of a palpable lump in the wrist and hand; in the lower limbs the majority are related to the foot and ankle. Treatment includes reassurance and/or surgical removal.

Epidermoid and pilar cysts

Epidermoid and pilar cysts are small smooth cystic lumps under the skin surface (also called sebaceousRelating to a sebaceous gland, a specialised gland in the skin producing sebum, an oily material that helps to lubricate and protect skin and hair. 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 anaestheticA medication that reduces sensation in a part of the body.. 

Haematomas 

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.

Abscesses

An abscess can often cause a painful soft tissue lump. An abscess is caused by an infectionInvasion by organisms that may be harmful, for example bacteria or parasites. that results in a collection of pusA pale yellow or green,creamy fluid found at the site of bacterial infection. within inflamed tissues. Treatment includes drainage and antibioticsMedication to treat infections caused by microbes (organisms that can't be seen with the naked eye), such as bacteria..

Chronic inflammation or granulomatous lesions 

Chronic inflammation or granulomatous lesions can mimic soft tissue tumours. Diagnosis can be established by imaging and tissue biopsy. The typical radiological appearance in chronic inflammation or granulomatous lesions is very different from soft tissue tumours and appears to lack uniformity, with ill-defined margins on imaging. A definitive diagnosis can be established with core needle biopsy and laboratory analysis.