Lipoma

ICD-11

2E80.0

Synonyms

Fatty tumor or steatoma.

Epidemiology

Relatively frequent tumor. Lipomas occur in 1-2% of the adult population. Males > females.

Definition

Adipocytic tumors are benign soft tumors of the skin, arising from the subcutaneous fat tissue.

Aetiology & Pathogenesis

Most frequently spontaneous but there may be a genetic predisposition (see subtypes).

Signs & Symptoms

Rubbery feeling, Indolent (slowly growing), soft, mobile, circumscribed, round, subcutaneous mass.

Localisation

Lipoma may be solitary, multiple or disseminated, and may occur anywhere.

Classification

Single or multiple (lipomatosis) non-pain associated lipomas
Subtypes: familial multiple lipomatosis, adiposis dolorosa (Dercum disease), a condition marked painful lipomas. Familial multiple lipomatosis, a hereditary condition that causes multiple lipomas. Benign symmetric lipomatosis (Madelung disease), a rare condition marked by lipomas forming around the upper body.

Laboratory & other workups

No laboratory tests are needed. Ultrasound.

Dermatopathology

Well limited fatty tissue lobules, frequently with a connective tissue capsule. Lipomas with vessel proliferation: angiolipomas; lipomas with connective tissue proliferation: fibrolipomas and mixed types: angiofibrolipomas.

Course

The typical course is a slow growth followed by stabilization.

Complications

Pressure on adjacent tissues and vessel thrombosis within the lipoma may rarely lead to pain, esthetic discomfort.

Diagnosis

Clinical characteristic features, ultrasonography, and histological confirmation if needed.

Differential diagnosis

Malignant liposarcoma (well-differentiated liposarcoma (WDL) / atypical lipomatous tumor (ALT) must be suspected if the tumor is rapidly growing or painful, and in this case the lesion must be removed surgically for histopathological examination. Other differential diagnoses: cysts, connective tissue tumours, benign symmetrical lipomatosis.

Prevention & Therapy

Excision is performed in case of discomfort, or to rule out a malignant tumor if the clinical presentation is atypical (e.g. rapid growth, pain).

3.2.5 Lipoma