A case of large tophaceous pseudogout occupying the infratemporal fossa

We report a case of large tophaceous pseudogout occupying the infratemporal fossa arising in the temporomandibular joint (TMJ). A 62-year-old woman was referred to our hospital with a chief complaint of pain in the right TMJ when she opened her mouth. She had diffuse swelling with mild tenderness in the right preauricular and the right buccal mucosal regions. Contrast-enhanced computed tomography revealed a 54-mm calcified mass-like lesion in the major axis occupying the infratemporal fossa. Compressive bone resorption in the condylar head, inner mandibular ramus, and the base of the skull, which was in contact with the mass, were also seen. Clinically, a masticator space tumor was suspected, and a biopsy of the mass was performed from the buccal mucosa region. The biopsy specimen revealed deposits of calcium pyrophosphate dehydrate (CPPD) crystals, and tophaceous pseudogout was thus diagnosed. With the patient under general anesthesia, an operation was performed from a preauricular and temporal approach as well as an intraoral approach to divide and remove the mass as much as possible. Although part of the mass remained, clinical symptoms disappeared after surgery. Three years 7 months postoperatively, the patient has not had any symptoms.