Axillary arch: detailed ultrasonographic images with multiplanar CT correlation.

The axillary arch is a common but rarely recognized anatomical variant of the axillary musculature. We report the first detailed presentation of the ultrasonographic features of the axillary arch and a correlation of these findings with multiplanar reformation CT images incorporating a schematic anatomical diagram in a 44-year-old woman complaining of a palpable non-tender mass in the axillary region due to a unilateral axillary arch. The clinical significance of the axillary arch is discussed.