17h10 Radiological and clinical differential diagnostics of CPPD in the temporomandibular joint extending into the cranium: insights from the literature and a rare clinical case.

Imaging has been proven to be useful in differentiating this benign disease from malignant or other aggressive processes that often present with similar local destruction. 

Calcium pyrophosphate deposition disease (CPPD) in the temporomandibular joint (TMJ) is rare but occasionally appears locally destructive. Various radiological techniques are available for differential diagnosis. We present the case of a 66 year old man with long-standing, painful, unilateral TMJ swelling. Radiological imaging showed a mass with calcifications, erosion of the articular roof and invasion of the middle cranial fossa. Differential diagnoses included CPPD, tenosynovial giant cell tumor, synovial chondromatosis, chondrosarcoma, and osteochondroma. A biopsy confirmed CPPD, followed by resection of the lesion and immediate TMJ reconstruction with a patient-specific prosthesis. Benign and malignant TMJ lesions extending into the cranium are uncommon and their radiological differentiation remains challenging. Therefore, we performed a scoping review focusing on TMJ imaging allowing differential diagnosis of CPPD.