Calcifying epithelioma of malherbe (Pilomatrixoma): Clinical and sonographic features.

PURPOSE: The purpose of this study was to describe the clinical and sonographic features of calcifying epitheliomas (pilomatrixomas).

METHODS: We retrospectively reviewed the clinical data and sonographic appearances of 59 cases of calcifying epitheliomas in 58 patients that were confirmed pathologically.

RESULTS: The mean age of the patients was 26 years (range, 5-69 years) and the female-to-male ratio was 1.2. All masses were located in subcutaneous soft tissues. Overall, 76.3% of the cases were located in the head and neck; the mean tumor size was 13 mm, and 72.9% of the cases were between 10 and 20 mm in size. Of the lesions, 62.7% were hypoechoic masses with internal calcifications, and 74.6% of them showed low or moderate internal vascularity on Doppler imaging.

CONCLUSIONS: The diagnosis of calcifying epithelioma should be considered in a patient with a painless, circumscribed, oval-shaped hypoechoic mass with internal calcifications and internal vascularity in the subcutaneous soft tissues of the head or neck. The mass may be small and have well-defined margins, with hypoechogenicity. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:3-7, 2018.