Tophaceous Pseudogout in the Temporomandibular Joint: A case report

抄録

We report an unusual case of tophaceous pseudogout that appeared in the right temporomandibular joint (TMJ) accompanied with painless swelling at periauricular region of a Japanese elderly man. Radiographic examination including computed tomographic images revealed an exophytic radiopaque lesion with clear boundaries in the right peri-condylar region. Surgical resection was employed, and a microscopic examination of the surgical specimen showed the deposition of basophilic rhomboidal crystals around which foreign body reactions including multinucleated giant cells and chondrogenicity were localized. Aggregates of rhomboid crystalline deposits were exposed under polarized light. Further elemental analysis confirmed the involvements of Ca and P and positive birefringence under a polarizing microscope, which helped in the histopathological diagnosis of tophaceous pseudogout.