subgaleal lipoma

Subgaleal lipomas are benign adipose-containing tumors that occur between the periosteum and the galeal aponeurosis of the scalp.

Epidemiology

They comprise 2% of all lipomas. They are more common in middle-aged patients and have a male predilection

Clinical presentation

Subgaleal lipomas present as a slow-growing, painless, firm and immobile swelling overlying the frontal scalp.

Pathology

Histology demonstrates mature adipocytes in a connective tissue stroma surrounded by the fibrous capsule, importantly they lack any cellular atypia or mitotic activity.

Radiographic features

Plain radiograph
  • oval or lens-shaped soft tissue/fatty swelling
  • smooth convex displacement of the galea aponeurosis
Ultrasound
  • oval or lens-shaped echogenic swelling
  • no increased vascularity or cystic features
  • located between periosteum and galea aponeurosis
  • smooth convex displacement of the galea aponeurosis
  • relatively flat base
CT
  • morphology and anatomical location as above
  • fat attenuation
MRI

The morphology and anatomical location of the lesion is as above.

  • T1: hyperintense
  • STIR: suppressed signal

Differential diagnosis

General imaging differential considerations include:

Practical points

Ideally, the radiology report would comment on the:

  • size, shape, and location of the lesion
  • note any vascularity or cystic features

See also

Siehe auch:
und weiter: