LIPOMAS

Dr. Ajayi Babajide O.Dept. of Family Medicine.

EKO Hospitals, Ikeja.

OUTLINEINTRODUCTIONEPIDEMIOLOGYAETIOLOGYCLASSIFICATIONCLINICAL FEATURESDIFFERENTIALSCOMPLICATIONSTREATMENT MODALITIES

INTRODUCTIONA lipoma is a benign soft tissue tumor

composed of adipose tissue (body fat) enclosed in a capsule of connective tissue.

It is the most common benign form of soft tissue tumor.

It may be arranged in lobules separated by fibrous septa.

It may also become pedunculated.

EPIDEMIOLOGYLipomas are commonly found in adults from

40 to 60 years of age but can also be found in younger adults and children.

Causes of LipomasThe tendency to develop a lipoma is not necessarily

hereditary although hereditary conditions, such as familial multiple lipomatosis, may include lipoma development.

Gardeners syndromeDercums’ syndrome

Cases have been reported where minor injuries are alleged to have triggered the growth of a lipoma, called “post-traumatic lipomas”. However, the link between trauma and the development of lipomas is controversial.

ClassificationThere are many methods of classification

Based on histologic typesBased on location

Superficial subcutaneous lipomas, the most common type of lipoma, They lie just below the surface of the skin. Most occur on the trunk, thigh, and forearm, although they may be found anywhere in the body where fat is located.

Adenolipomas are lipomas associated with eccrine sweat glands.

Angiolipoleiomyomas are acquired, solitary, asymptomatic acral nodules, characterized histologically by well-circumscribed subcutaneous tumors composed of smooth muscle cells, blood vessels, connective tissue, and fat.

Angiolipomas painful subcutaneous nodules having all other features of a typical lipoma.

Cerebellar pontine angle and internal auditory canal lipomas.

Chondroid lipomas are deep-seated, firm, yellow tumors that characteristically occur on the legs of women.[4]:625

Corpus callosum lipoma is a rare congenital brain condition that may or may not present with symptoms. This occurs in the corpus callosum, also known as the colossal commissure, which is a wide, flat bundle of neural fibers beneath the cortex in the human brain.

Hibernomas are lipoma of brown fat.

Intradermal spindle cell lipomas are distinct in that they most commonly affect women and have a wide distribution, occurring with relatively equal frequency on the head and neck, trunk, and upper and lower extremities.

Neural fibrolipomas are overgrowths of fibro-fatty tissue along a nerve trunk, which often leads to nerve compression.

Pleomorphic lipomas, like spindle-cell lipomas, occur for the most part on the backs and necks of elderly men and are characterized by floret giant cells with overlapping nuclei.

Spindle-cell lipomas are asymptomatic, slow-growing subcutaneous tumors that have a predilection for the posterior back, neck, and shoulders of older men.

HISTORYHistory-taking is guided by the anatomical

location of the lesion. Questions should explore factors such as:

When the lump was first noticedWhat brought the lump to the attention of the

patientThe symptoms that are related to the lumpChanges that have occurred to the lump since it

first appearedWhether the lump ever disappears and what

causes it to reappearWhether the patient ever had any other lumps

and what they were likeWhether there has been any loss of body weightWhether the lump has been treated before and

has recurred.

CLINICAL FEATURESMost lipomas are small (under one centimeter

diameter) but can enlarge to sizes greater than six centimeters.

Localized, LobularFluctuant.Mobile.Exhibit “Slip sign”. (They move easily when pressure is

placed on them)Skin free.SoftOn examination they do not exhibit differential warmth.Lipomas are usually painless soft and non tender.

Reaching a DiagnosisThis is usually done clinically. Any doubt about the

diagnosis calls for immediate refferall to a dermatologist.

Ancillary investigations include:- Pre-operative radiography Both ultrasound and magnetic resonance imaging

have been used with some success to differentiate lipomas and liposarcomas but are not entirely reliable.

CT scan are occasionally required.Alternatively, fine-needle aspiration may be used to

evaluate suspicious lesions

Differential DiagnosisThese include but are not limited to:-FibrosarcomasAbcesses (Localized)Cold abcessesNeurofibromasHerniasPappilomaSebaceous cysts (contain sebum. Affect the s.glands)Epidermoid cysts (contain keratin and fat)Nodular fasciitisErythema nodosumNodular subcutaneous fat necrosisHaematoma

Sebaceous cysts

Draining Sebum

Epidemoid Cyst

COMPLICATIONSMyxomatous degenerationSaponificationCalcificationInfectionUlcerationIntussusception & intestinal obstructionSome sources claim that malignant

transformation can occur while others say this has yet to be convincingly documented.

Treatment of Lipomas

Indications for TreatmentUsually, treatment of a lipoma is not necessary,

unless the tumor becomes painful or restricts movement. They are usually removed for cosmetic reasons,

However reasons to remove lipomas include when they grow very large, or for histopathology to check that they are not a more dangerous type of tumor such as a lipo-sarcoma. This last point can be important as the actual characteristics of a “lump" is not known until after it is removed and medically examined.

LiposarcomaThis malignancy is rare but can be found in a

lesion with the clinical appearance of a lipoma. Liposarcoma presents in a fashion similar to that of a lipoma and appears to be more common in the retro peritoneum, on the shoulders and lower extremities.

Hence some recommend an immediate and complete excision of a lipoma with subsequent histologic studies to exclude a possible Liposarcoma,

Suspicious Signs that warrant immediate removalIf the lump suddenly starts to grow very largeGreater than 5 cm in diameterLocated in the extremities, retroperitoneally,

in the groin, in the scrotum or in the abdominal wall

Deep (beneath or fixed to superficial fascia)Exhibiting malignant behaviour (invasion into

nerve or bone)

Surgical excision of LipomasThey can be left alone. They may need to be removed for

cosmetic reasons, because of compression of surrounding structures or if the diagnosis is uncertain

Lipomas are normally removed by simple excision. The removal can often be done under local anaesthetic, and takes fewer than 30 minutes. This cures the great majority of cases, with about 1–2% of lipomas recurring after excision.

. Because lipomas generally do not infiltrate into surrounding tissue, they can usually be shelled out easily during excision.

Minimal scarring can be achieved with a technique called segmental extraction - a small stab incision followed by blind dissection of the lipoma and extraction in a segmental fashion

Liposuction is another option if the lipoma is soft and has a small connective tissue component. Liposuction typically results in less scarring; however, with large lipomas it may fail to remove the entire tumor, which can lead to re-growth.

New methods under development are supposed to remove the lipomas without scarring. One is removal by injecting compounds that trigger lipolysis, such as steroids or phosphatidylcholine.