Case report: Calcium pyrophosphate dihydrate deposition of the temporomandibular joint diagnosed by fine-needle aspiration cytology.

Calcium pyrophosphate dihydrate deposition (CPDD) is the accepted name for a disease that mainly occurs in elderly patients. This disease affects many joints in particular the knee joint. CPDD is extremely rare in the temporomandibular joint (TMJ) with only few cases reported in the English literature. Herein, we present a case of an 89 years old woman with a radiological diagnosis of chondrosarcoma of TMJ. Fine-needle aspiration cytology however showed crystals, multinucleated giant cells and macrophages which allowed a correct diagnosis of CPDD.