This report presents a case of extensive tophaceous pseudogout involving the temporomandibular joint (TMJ), causing erosion into the middle cranial fossa. Pseudogout is a benign metabolic arthropathy caused by calcium pyrophosphate dihydrate crystal deposition within joints and peri-articular tissue. Pseudogout more frequently occurs in large joints such as the knee, wrist, symphysis pubis, and shoulder. Tophaceous pseudogout involving the TMJ is rare, with only seven cases involving erosion into the middle cranial fossa reported previously. Despite skull base erosion being a rare consequence of this erosive disease, this case highlights the importance of appropriate investigation and multidisciplinary team management.

Calcium pyrophosphate dehydrate deposition (CPDD) disease very rarely affects the temporomandibular joint (TMJ). It may resemble synovial chondromatosis, chondrosarcoma, chondroblastoma, or a parotid tumor. Clinical examination, CT, and MRI are important in making the correct diagnosis. Surgical removal of CPDD is necessary with or without excision of the TMJ.

A case of tophaceous pseudogout (i.e., calcium pyrophosphate dihydrate crystal deposition disease) in the temporomandibular joint (TMJ) extending into the cranium is reported. A 59-year-old woman was referred to hospital with swelling and pain in the left cheek, and with trismus. Computed tomography imaging revealed a large, granular, calcified mass surrounding the left condylar head, partly destroying the cortex of the condylar head, and extending into the cranium by destroying the glenoid fossa. Magnetic resonance imaging revealed that the soft-tissue mass was of low-signal intensity on T1- and T2-weighted images, and was enhanced after intravenous injection of gadolinium. The mass was clinically and radiographically suspected to be a neoplastic lesion or a synovial osteochodromatosis. However, histological analysis demonstrated that the mass contained granulomatous lesion due to multiple nodular deposits of numerous rod-shaped and rhomboid crystals, which verified the diagnosis of tophaceous pseudogout. The lesion was excised surgically using a preauricular approach. Neither radiographic nor clinical examination demonstrated any signs of mass recurrence in the long-term 8- and 14-year postoperative recall examinations. Tophaceous pseudogout is a rare benign arthropathy that presents with clinical and radiographic features mimicking neoplastic conditions of the TMJ. Therefore, it is recommended that tophaceous pseudogout is considered in the differential diagnosis when a calcified mass lesion of the TMJ is encountered.

We report a series of 3 cases of tophaceous pseudogout of the temporomandibular joint (TMJ).

Three patients, two men and one woman, ranging in age between 60 and 75 years, presented with unilateral painful swelling of the TMJ area associated with limitation of mouth opening.

Radiographic and computed tomographic images showed opaque masses in the supracondylar region of the TMJ. The preoperative clinical impression was a "neoplastic lesion" in the 3 cases. Microscopic examination revealed numerous deeply basophilic masses of calcified deposits, exhibiting birefringence under polarized light and morphologically consistent with calcium pyrophosphate dihydrate deposition, referred to in these cases as "tophaceous pseudogout."

Tophaceous pseudogout is a rare benign arthropathy that presents with clinical and radiographic features mimicking neoplastic conditions of the TMJ. Therefore, it is recommended that tophaceous pseudogout be considered in the differential diagnosis when a TMJ is involved with "neoplasm-like" lesions clinically and radiographically.

Pseudogout, or calcium pyrophosphate deposition, is a rare cause of pain, swelling, and trismus of the temporomandibular joint (TMJ). Diagnosis and management of the lesion are discussed.

A 58-year-old female had a 2-month history of progressive swelling of right TMJ associated with trismus and facial pain. Imaging of the TMJ revealed a mixed radiolucent and radiopaque lesion associated with the right TMJ joint space. Surgical excision was performed successfully via preauricular approach. Pathology was consistent with calcium pyrophosphate deposition of the TMJ, also known as pseudogout. Surgical excision successfully treated her symptoms as expected. She is now disease free without recurrence.

Pseudogout is a rare cause of TMJ pain, swelling, and trismus that should be included in the differential of joint pain and dysfunction. It can be treated successfully with surgery.

Pseudogout of the temporomandibular joint (TMJ) is a rare disorder with <40 reported cases in the English-language literature. It is usually treated with surgical resection and condylectomy alone.

We report the case of a 68-year-old woman presenting with a preauricular mass resulting from calcium pyrophosphate deposition (pseudogout) in the TMJ, who underwent surgical resection with immediate reconstruction.

Open surgical resection to completely remove the mass confirmed substantial erosion of the condyle and disc, necessitating condylectomy and discectomy. The joint was thereafter immediately reconstructed by total joint arthroplasty using a Christensen TMJ implant sized to the patient's anatomy. The patient was able to resume a regular diet and demonstrated marked improvement in her interincisal opening.

Immediate reconstruction of the TMJ with total joint arthroplasty is a safe and effective measure following removal of this (and potentially other) TMJ lesions.