Ultrasound features of painful intraosseous migration of pectoralis major tendinous calcifications with follow-up.

Calcific tendinitis is a common disorder in adults. Although rare, humerus involvement associated with pectoralis major tendon calcification migration has previously been reported in studies that focus on its CT and MRI appearance. We present four cases of intraosseous migration of pectoralis major tendon calcification and their ultrasound features. Calcification migration into osseous structures is associated with cortical erosions, intraosseous calcifications, and bone marrow edema. These findings may be misleading on MRI, where the significant bone marrow and surrounding tissue inflammation may raise concerns regarding neoplasia and lead to unnecessary invasive biopsy. In these cases, echography can be less alarming, enabling the identification of the calcification, its location in the pectoralis major tendon enthesis, and the continuity between the calcification and the typical cortical erosion. Ultrasound features may be diagnostic and might help avoid additional costly imaging studies or invasive biopsy.