Tumoral Calcium Pyrophosphate Deposition in the Glenohumeral Joint: A Case Report
Chikara Watanabe, Yohei Harada, Shuhei Matsumura, Shin Yokoya, Nobuo AdachiCase
A 75‐year‐old male patient presented with long‐standing pain and swelling in the shoulder. Radiographic evaluations revealed a large, calcified mass posterior to the humeral head, without apparent bone erosion or destruction. Magnetic resonance imaging demonstrated an intra‐articular mass‐like lesion in the glenohumeral joint without apparent extension into the adjacent bone or surrounding soft tissues. Because the lesion appeared nonaggressive on imaging, a benign calcified intra‐articular lesion was initially considered. Open and arthroscopy‐assisted excision of the lesion was performed because of severe pain and restricted range of motion. Pathological examination demonstrated abundant crystalline deposits with angular and elongated morphology, consistent with calcium pyrophosphate deposition disease, leading to the diagnosis of tophaceous pseudogout. Two years after the surgery, radiography showed mild enlargement of the residual calcific deposits, although the patient remained asymptomatic.
Conclusion
Tophaceous pseudogout of the glenohumeral joint is rare and may mimic neoplastic lesions on imaging; therefore, it should be considered in the differential diagnosis of calcified masses in the shoulder.