RESUMO
BACKGROUND: Giant cell arteritis is an enigmatic disease that is characterized by chronic granulomatous inflammation of the walls of large and medium-sized arteries. The process has a predilection for the extradural cranial arteries, which include the ophthalmic and the posterior ciliary arteries. A multisymptom disease of older individuals, giant cell arteritis often manifests challenging issues and diagnostic dilemmas. CASE REPORTS: We illustrate two cases with initial symptoms of intermittent headache, malaise, and decreased visual acuity that were incorrectly diagnosed or ultimately misdiagnosed. The first case represents a patient who was diagnosed as having migraine headache and an erythrocyte sedimentation rate (ESR) that was interpreted by the attending physician as too low to warrant temporal artery biopsy. The second case is that of a patient who had a history of headaches, jaw claudication, and numerous medical evaluations. CONCLUSION: Giant cell arteries is an enigmatic disease with multiple manifestations. The differential diagnoses can range from temporal mandibular joint dysfunction to tension headache. Imminent vision loss as a sequelae of this condition warrants careful review of ocular and constitutional history and prompt treatment.