3. INTRODUCTION
A 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.
4. EPIDEMIOLOGY
Lipomas are commonly found in adults from 40 to 60
years of age but can also be found in younger adults
and children.
5. Causes of Lipomas
The tendency to develop a lipoma is not necessarily
hereditary although hereditary conditions, such as familial
multiple lipomatosis, may include lipoma development.
Gardeners syndrome
Dercums’ 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.
6. Classification
There are many methods of classification
Based on histologic types
Based 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.
7. 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.
8. 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.
9.
10. HISTORY
History-taking is guided by the anatomical location of the
lesion. Questions should explore factors such as:
When the lump was first noticed
What brought the lump to the attention of the patient
The symptoms that are related to the lump
Changes that have occurred to the lump since it first
appeared
Whether the lump ever disappears and what causes it to
reappear
Whether the patient ever had any other lumps and what
they were like
Whether there has been any loss of body weight
Whether the lump has been treated before and has
recurred.
11. CLINICAL FEATURES
Most lipomas are small (under one centimeter diameter)
but can enlarge to sizes greater than six centimeters.
Localized,
Lobular
Fluctuant.
Mobile.
Exhibit “Slip sign”. (They move easily when pressure is
placed on them)
Skin free.
Soft
On examination they do not exhibit differential warmth.
Lipomas are usually painless soft and non tender.
12. Reaching a Diagnosis
This 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
13. Differential DiagnosisThese include but are not limited to:-
Fibrosarcomas
Abcesses (Localized)
Cold abcesses
Neurofibromas
Hernias
Pappiloma
Sebaceous cysts (contain sebum. Affect the s.glands)
Epidermoid cysts (contain keratin and fat)
Nodular fasciitis
Erythema nodosum
Nodular subcutaneous fat necrosis
Haematoma
17. COMPLICATIONS
Myxomatous degeneration
Saponification
Calcification
Infection
Ulceration
Intussusception & intestinal obstruction
Some sources claim that malignant transformation can
occur while others say this has yet to be convincingly
documented.
19. Indications for Treatment
Usually, 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.
20. Liposarcoma
This 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,
21.
22. Suspicious Signs that warrant
immediate removal
If the lump suddenly starts to grow very large
Greater than 5 cm in diameter
Located 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)
23. Surgical excision of Lipomas
They 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
24.
25. 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.
26. 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.
