A case of destructive calcium pyrophosphate dihydrate crystal deposition disease of the temporomandibular joint: a diagnostic challenge.

The authors present the case of a 64-year-old woman with a destructive calcium pyrophosphate dihydrate (CPPD) crystal deposition disease of the temporomandibular joint. Progressive pain, swelling and a malocclusion were her chief complaints. A few granular calcified masses surrounding the left condylar head and extending to the infratemporal fossa and middle cranial base were presented in CT images. It occurred alone without other joints being affected. A provisional diagnosis of occupying lesion with invasion was made preoperatively, but histologically, the mass contained numerous deposits of rod-shaped or rhomboid crystals, which were positively birefringent under a polarising microscope, suggesting a CPPD deposition disease. The histopathological diagnosis was further supported by scanning electron microscopy with energy dispersive X-ray spectroscopy. The diagnosis, differential diagnosis and treatment of this disease are discussed.