There are many non-cancerous skin lesions that can present as a lump/nodule. They are generally slow growing and do not cause much in terms of symptoms. 

Most people seek surgical review when the lump is located in an exposed part of the body or because of the size and become aesthetically unappealing. Sometimes the lump can rupture and/or become infected.
Common skin lumps that come to surgical attention are:

  • Sebaceous cysts (including epidermoid, trichilemmal and epidermal inclusion cysts)
  • Lipoma

 

Sebaceous Cysts

This is a condition where accumulation of a cheese-like substance is found in the outermost layer of the skin, epidermis. Sebaceous cysts are mostly found on the face, neck, or torso. They grow slowly and are not life threatening, but they may become uncomfortable if they go unchecked. Diagnosis usually can be made with good physical examination and medical history. In some cases, a cyst will be examined more thoroughly for signs of cancer.

Causes of a Sebaceous Cyst

Sebaceous cysts form out of sebaceous gland—which produces the oil called sebum that coats your hair and skin. Cysts can develop if the gland or its duct become damaged or blocked. This usually occurs due to a trauma to the area. The trauma may be a scratch, a surgical wound, or a skin condition, such as acne. Sebaceous cysts grow slowly. The trauma may occur months or weeks before you notice the cyst.
Other causes include:

  • Developmental defect: a person may be born with a misshapen or deformed duct
  • Damage to the cells during surgery
  • Genetic conditions, such as Gardner’s syndrome

Symptoms of Sebaceous Cyst

Sebaceous cysts are generally found on skin that is easily seen—such as the face, neck, or torso. This can make the affected person uncomfortable since the cysts might be considered unattractive. Apart from the cosmetic effect, small sebaceous cysts generally do not cause any symptoms. The cysts can become infected and hence, painful. A large cyst may spontaneously rupture and extrude its content, that is cheesy-like and maladorous.

Diagnosis of a Sebaceous Cyst

Diagnosis is often easily made with good physical examination and medical history. If your cyst is unusual, your doctor may order additional tests to rule out possible cancers. Common tests used for a sebaceous cyst include:

  • Ultrasounds
  • Rarely other investigations/imaging will be needed unless the cyst is unusual

Treatment

Surgery is the only effective treatment for sebaceous cyst. The best treatment is to ensure complete removal of the entire cyst. This involved cutting out a part of the overlying skin and removing the entire cyst intact (complete excision). Sometimes when the cyst had become infected and developed into an abscess, the cyst will be incised and drained (incision and drainage). Without surgical removal, your cyst will usually come back. In this case, once the infection settled, you should consider having the cyst completely excised.

Complications of surgery

  • Infection
  • Scar formation

Outlook for a Sebaceous Cyst

Sebaceous cysts are generally not cancerous. However, they can be unattractive. Cysts left untreated can become very large and may eventually require a surgical removal if they become uncomfortable or complications such as infection develops. If you have a complete removal, the cyst will not return in the future. There is a risk of scarring, but this can be minimised with good surgical techniques. Without a complete removal, the cyst can come back at any point.

Lipoma

A lipoma is a slow-growing, fatty lump that is often situated between your skin and the underlying muscle layer. It is one of the most common benign soft tissue tumour. A lipoma feels soft and is usually not tender. Some people have more than one lipoma. Most lipoma is not cancerous and usually is harmless. Treatment generally is not necessary, but if the lipoma bothers you, is painful or is growing, you may want to have it removed. A rapidly growing lipoma warrants urgent surgical review as this may indicate a cancerous growth (liposarcoma).

Symptoms of Lipoma

Lipoma develops from the normal fatty tissue under the skin. They commonly occur in the neck, shoulders, back, abdomen, arms and thighs. Rarely, they can be situated deep to or within the muscle. Lipoma generally does not produce any symptoms. Sometimes because of their location, people feel uncomfortable of the cosmetic appearance. Sometimes a lipoma can cause discomfort or pain, especially if they are large and pressing on a nerve.

Causes of lipoma
The cause of lipoma is unknown. Lipoma tend to run in families, so genetic factors are likely to play role in their development.

Diagnosis

The diagnosis can often be made with a good physical examination and medical history. Sometimes an ultrasound or other imaging test, such as an MRI or CT scan, may be ordered if the lipoma is large, has unusual features or appears to be deeper than the fatty tissue. In very rare cases, a lump resembling a lipoma may actually be a form of cancer called liposarcoma. Liposarcomas — cancerous tumors in fatty tissues — grow rapidly, don't move under the skin and are usually painful. A biopsy, MRI or CT scan is typically done if liposarcoma is suspected.

Treatment

If the lipoma is small, not causing symptoms and bothering you, no treatment is necessary. Otherwise, surgery is the only effective treatment. This involves cutting out the lipoma.
Complications of surgery:

  • Infection
  • Scar formation
  • Seroma (fluid) accumulation