18- and 70-MHz Ultrasonography of Actinomycetoma of the Foot Correlated with Clinical and Histologic Findings.

We present the ultrasonographic morphology of an actinomycetoma of the foot at 18 and 70 MHz (high-frequency and ultrahigh-frequency ultrasound, respectively), and describe an ultrasonographic sign that may help to discriminate between eumycetoma and actinomycetoma called the "bright hyperechoic halo." To date, this is the first report on the morphology of mycetoma at 70 MHz with a clinical, ultrasonographic, and histologic correlation of the images, which provides ultrasound images that are very similar to the lower magnification of histology.