A case of the calcium pyrophosphate dihydrate (CPPD) deposition disease without condylar destruction of the temporomandibular joint

The case of calcium pyrophosphate dihydrate (CPPD) deposition disease, which occurred at a rare site in the temporomandibular joint (TMJ), is presented. A 48-year-old woman noted swelling in the preauricular area of her left cheek, which restricted her mouth opening. Radiological examination revealed a radiopaque lesion in the posterior and medial area of the left space of the TMJ. During the operation, the superior joint space was entirely filled with a solid and whitish-gray mass of chalky appearance. The lesion was partly attached to the retrodiscal tissue without any destructive change around the condyle and mandibular fossa. Histological examination revealed the foci of amorphous crystalline material to contain rhomboidal, rod and needle shaped crystals, which had cartilaginous tissue in the dense fibrous background admixed with chronic inflammatory cells and foreign body-type giant cells. The crystals were positive for von Kossa's stain and spectral peaks for phosphorus and calcium were evident by electron probe microanalysis, thus suggesting the presence of CPPD.