Practicing restraint after incidental finding of Pseudotumor deltoideus: A case report

Abstract

Pseudotumor deltoideus refers to a benign anatomic variation of the humerus at the site of deltoid insertion. These lesions typically present with shoulder and/or arm pain and decreased range of motion, but may be found incidentally. On plain radiographs, a pseudotumor deltoideus is an area of cortical thickening with intracortical lucency at the region of the deltoid tuberosity. This relatively uncommon finding casts a diagnostic gray cloud over radiologists and musculoskeletal experts because of its similarity to aggressive periosteal reactions and lucencies seen in more threatening neoplastic conditions and infections. We present a case of a 25 year old female patient with intermittent right shoulder and neck pain associated with numbness and tightness radiating down the right arm to the wrist. Radiographs of the right shoulder revealed an area of cortical thickening in the right humeral diaphysis at the level of the deltoid insertion, which was diagnosed as pseudotumor deltoideus. Physicians that treat musculoskeletal conditions should feel comfortable with how to differentiate this diagnosis in order to reduce patient discomfort and medical fees secondary to unnecessary biopsies or blood work.