lipoma

Question 1

definition of lipoma

Answer 1

slow growing benign tumours of adipose tissue

lipomatosis = multiple contiguous lipomas that cause distortion of SC tissue eg on buttock and rarely neck

classified by location eg SC, subfascial, subsynovial

Question 2

aetiology of lipomas

Answer 2

unknown

certain chromosomal aberrations have been implicated - eg translocation of a gene on Chr 12

Question 3

RF for lipoma

Answer 3

rare presentation is multiple tender lipomas (dercum’s disease/adiposis dolorosa) - typically in post menopausal women

Question 4

epidemiology of lipoma

Answer 4

all ages

mostly 40-60yrs, rare in children

Question 5

sx of lipomas

Answer 5

lump - painless and slowly enlarging

unless subject to trauma when fat necrosis may cause it to swell and become tender

sx only occur with pressure

Question 6

signs of lipoma

Answer 6

happens anywhere there are adipose reserves - common in SC tissue of upper arms

non-tender, soft, compressible

dont fluctuate or transilluminate unless large

no fluid thrill and are dull to percussion

overlying skin is normal

variable size, usually ovoid or spherical, often lobulated (a useful dx feature)

smooth impresise margins

not fixed to deeper structures or skin

local LN not palpable

Malignant change very rare (suspect if rapid growth/hardening/vascularization)

Question 7

pathology of lipomas

Answer 7

arise in any connective tissue but most common in SC fat

histologically made of collections of adipose cells, indistinguishable form normal adipocytes, divided into large lobules by thin fibrous septa

Question 8

Ix for lipoma

Answer 8

usually non necessary

MRI can be used for visualising deeply sited lipomas