Whenever a patient is seen with a palpable extremity mass, the clinical question is often whether the lesion is benign or malignant. The history, physical examination, laboratory findings, and imaging studies must all be considered to arrive at a probable diagnosis and to formulate an appropriate management plan. In cases of suspected malignancy, the next step is often to take a biopsy. However, traumatic lesions should not undergo removal of biopsy tissue because removal could exacerbate the underlying condition, complications could occur, or worse, an exuberant tissue reaction could be mistaken for a malignant process. We report on a high-school football player with an upper extremity lesion who was referred to our orthopaedic oncology clinic for a suspected malignancy of the forearm. He was found to have bilateral ossifying periostitis of the ulnas due to repetitive trauma. The correct diagnosis was obtained by correlating the imaging studies with the clinical history and physical examination.We reviewed the current literature on ulnar stress fractures and posttraumatic ossifying periosteal lesions masquerading as malignant lesions.
CASE REPORTA 17-year-old male high-school student was seen at an outside facility and reported 2 weeks of pain and tenderness over his left ulna. Plain radiographs revealed periosteal new bone formation along the ulnar border of the left ulna with a few cystic lucencies within this new bone (Fig. 1). A CT scan showed a &dquo;sunburst&dquo; pattern of periosteal new bone formation with some erosion of the volar cortex of the ulna (Fig. 2). A magnetic resonance imaging (MRI) scan of the same area revealed both periosteal and marrow abnormalities, which were of low-signal intensity on T1-weighted images and of increased signal intensity on T2-weighted images (Fig. 3). I%+ a , $ Q # z Figure 1. Plain radiograph of the left forearm shows periosteal new bone formation along the diaphysis of the ulna. Also note the small, vague cystic lucencies within this periosteal new bone.
