Head and neck lipomas: sonographic appearance.

PURPOSE: The diagnosis of cervical lipoma may not always be clinically apparent, in which case patients are frequently referred for sonography. The purpose of this study was to document the sonographic features of head and neck lipomas.

METHODS: Twenty-five patients with soft-tissue masses in the neck had sonography as their initial imaging study. A lipoma was suspected on the basis of findings at clinical examination in only eight of these patients. Lipoma was confirmed by fine-needle aspiration cytology in 11 patients, by excision biopsy in five patients, by CT in two patients, and by clinical examination with clinical sonographic follow-up (6 months to 2 years) in seven cases.

RESULTS: Lipomas were well-defined (88%), compressible (100%), elliptical masses with the longest diameter parallel to the skin surface. All contained multiple echogenic lines parallel to the skin surface with no evidence of posterior enhancement or attenuation and no flow on color Doppler sonography. Compared with adjacent muscle, 76% of all lipomas were hyperechoic, 8% isoechoic, and 16% hypoechoic.

CONCLUSION: The characteristic sonographic appearance of head and neck lipomas is that of an elliptical mass parallel to the skin surface that is hyperechoic relative to adjacent muscle and that contains linear echogenic lines at right angles to the ultrasound beam.