Calcium Pyrophosphate Deposition Disease of the Temporomandibular Joint

Abstract

Calcium pyrophosphate dihydrate deposition disease (CPDD) is a rare crystal arthropathy characterized by the deposition of calcium pyrophosphate crystals in joint spaces, episodes of synovitis, and radiological features of chondrocalcinosis. 1,2 While the disease is most prevalent in the shoulders, pelvis, knees, and joints of the hands, the axial skeleton can be affected, but rarely involves the skull base. 2-4 When involved, CPDD can cause symptoms mimicking more common neuro-logical and neurosurgical pathologies. 2,5 We present a patient who was recently treated at our institution whose pathology demonstrated CPDD. Case Report The patient is a 51-year-old right-handed Caucasian woman with a 12-month history of left ear pain that originated from the temporomandibular joint (TMJ), with some associated swelling, pain with chewing, and mild hearing loss. Her physical examination revealed mild hearing loss on the left side. Computed tomography (CT) and magnetic resonance imaging of the temporal fossa revealed a large mass emanating from the temporal bone at the TMJ (►Fig. 1A, 1B), extending into the greater wing of the sphenoid, and involving the mastoid bone and air cells posteriorly. There was erosion of the petrous carotid canal. A CT-guided biopsy was performed which diagnosed the mass as tophaceous pseu-dogout (tumoral CPDD). Keywords ► temporomandibular joint ► calcium pyrophosphate ► CPDD ► chondrocalcinosis ► tophaceous pseudogout Abstract Calcium pyrophosphate dihydrate deposition disease (CPDD, tophaceous pseudogout) is a rare crystal arthropathy characterized by calcium pyrophosphate crystal deposition in joint spaces, episodes of synovitis, and radiological features of chondrocalcinosis. We present a case of 61-year-old woman who presented with left temporomandibular joint (TMJ) pain, difficulty chewing, left facial numbness, left-sided hearing loss, and left TMJ swelling. Imaging of the temporal fossa revealed a large mass emanating from the temporal bone at the TMJ, extending into the greater wing of the sphenoid and involving the mastoid bone and air cells posteriorly. Fine needle aspiration demonstrated polarizable crystals with giant cells. Intraoperatively, the TMJ was completely eroded by the mass. Final pathology was consistent with tophaceous pseudogout. CPDD has rarely been reported involving the skull base. None of the cases originally described by McCarty had TMJ pseudogout. Symptoms are generally pain, swelling, and hearing loss. Management is nearly always surgical with many patients achieving symptomatic relief with resection. CPDD is associated with many medical problems (including renal failure, gout, and hyperparathyroidism), but our patient had none of these risk factors. This case demonstrates that CPDD can involve the skull base and is best treated with skull base surgical techniques. Ã