Lipoma

Question 1

Define Lipoma

Answer 1

Benign, slow-growing, mesenchymal tumours that form from well-circumscribed, lobulated lesions composed of adipocytes

Question 2

Aetiology of Lipoma

Answer 2

Idiopathic
Hereditary: Familial multiple lipomatosis | Gardner’s syndrome | HMG 1-C gene mutation | Madelung’s (benign lipomatosis of head, neck, shoulder, proximal extremities) in men with heavy alcohol consumption | Dercum’s disease/adiposis dolorosa (painful lipoma on trunk, shoulders, arms, legs in middle aged women | Bannayan-Riley-Ruvalcaba syndrome | Proteus syndrome | MEN-1

Question 3

Symptoms of Lipomas

Answer 3

Lipomas usually arise in the subcutaneous tissues and may occur in any area of the body, although they most frequently occur on the trunk and proximal limbs

Cutaneous mass (Painless (angiolipomas may  be painful)
GI obstruction and bleeding (Submucosal lipoma in the GIT, often oesophagus, stomach, SI)
Muscle weakness (retroperitoneal lipoma invades/exerts pressure on neurovascular strictures)
Parasaethesia

Question 4

Signs of Lipoma on physical examination

Answer 4

Cutaneous mass <5cm in diameter (liposarcoma usually >5cm)

• Soft, doughy in texture
• Demarcated from surrounding fat by a thin, fibrous capsule
• Mobile (liposarcoma more likely to be fixed)
• Superficial

Abdominal mass

Question 5

Investigations for Lipoma

Answer 5

USS: discrete, encapsulated, homogenous mass

Symptomatic/enlarging/>3cm:
MRI: Typically discrete, encapsulated, homogeneous mass, with few or no thin, discrete septa
CT: “
Biopsy (core needle preferred): well-circumscribed, lobulated, mesenchymal tumours composed of adipocytes and demarcated from surrounding fat by a thin, fibrous capsule.