Transient myometrial contraction as a physiological phenomenon may simulate pathological conditions, such as a focal or diffuse adenomyosis. Clinicians should be aware of the potential presence of this phenomenon and imaging should be repeated after a suitable interval when the nature of a bulge or a region of low intensity in the myometrium is in doubt. In this paper, we report a transient myometrial contraction that mimics an adenomyosis, but disappears in repeated series.