Intraosseous migration of calcific supraspinatus tendonitis: a case report.

Calcific tendinitis is a common and generally benign condition caused by the deposition of calcium hydroxyapatite crystals within tendons, most frequently affecting the rotator cuff, particularly the supraspinatus tendon. While often asymptomatic, some cases can present with acute pain and functional impairment. In rare instances, intraosseous migration of these calcifications can occur, leading to diagnostic challenges due to imaging findings that may mimic infectious or neoplastic bone lesions. We report the case of a 50-year-old woman presenting with acute, severe right shoulder pain without trauma history. Conventional radiography showed a calcific density adjacent to the lesser tuberosity. Magnetic resonance imaging confirmed intraosseous migration of the calcification, with perilesional bone marrow edema, cortical erosion, and associated subscapularis tendinitis without tendon rupture. The patient received conservative treatment, including analgesics, non-steroidal anti-inflammatory drugs, rest, and physical therapy, resulting in significant clinical improvement without the need for invasive procedures. This case highlights the importance of recognizing intraosseous migration of calcific tendinitis as a rare but benign entity.