Lipoma
Most common benign soft-tissue neoplasm
Pathophysiology
[edit | edit source]- Mature fat cells enclosed by thin fibrous capsule
- Can occur on any part of the body - most frequently trunk and upper extremities
- Usually found superficially in the subcutaneous tissue
- Malignant transformation into a liposarcoma is rare
- Concerning features for liposarcoma:
- Tumour size >10cm (sometimes >5cm)
- Presence of thick (>2mm septa)
- Presence of non-adipose areas
- Lesions <75% adipose tissue
- Deep to fascia
- Rapid growth
- Vascularity
Presentation
[edit | edit source]- Soft, painless subcutaneous nodules ranging in size from 1 to >10cm
- Slip sign - can't grasp it properly
Differential
[edit | edit source]- Liposarcoma
- >10cm
- Septa >2mm thick
- Presence of non-adipose areas
- Lesions that are <75% adipose tissue
- Familial multiple lipomatosis - multiple lipomas in several family members
- Epidermoid cyst
- Ganglion cyst
- Angiolipoma
- Mostly painful
- Mostly found on arms and chest wall
- Typically adolescents and young adults
- Admixture of mature adipose cells and capillaries
Excision
[edit | edit source]- Mark it pre-operatively in the position the patient is going to be in
- Incision directly over the lesion, along skin tension lines, across the full diameter
- Cut down onto the lipoma with knife (look for the lobulated bright yellow fat - really looks different to subcutaneous fat)
- Put a Littlewood's on and keep tension on as you gradually dissect around with scissors
- If it's bleeding, you're in the wrong plane
- You can sometimes excise a crescent of skin if it was bulging out, to prevent loose skin
- Close