An atypical manifestation of Giant cell arteritis (GCA): constitutional symptoms & lingual ulcer in a 78-Year-Old male with negative temporal artery biopsies.

Background: Giant cell arteritis (GCA) is a large vessel vasculitis characterized by granulomatous inflammation classically affecting the carotid artery branches. GCA most often presents with one or more classic clinical features which include headache, jaw claudication, temporal scalp tenderness, and polymyalgia rheumatica. In a minority of cases, GCA can adopt an "occult" presentation (i.e., failure to thrive in the setting of unexplained inflammation) where vascular manifestations affect vascular beds, such as lingual ulceration, not amenable to biopsy. While the diagnosis of GCA is often supported by temporal artery biopsy or imaging studies, such as temporal artery ultrasound or magnetic resonance angiography, these techniques are known to have limited sensitivity. As a result, there is the potential for GCA to be misdiagnosed where it presents both in the absence of classic clinical manifestations and without clear diagnostic evidence by imaging or histopathology.

Case presentation: A 78-year-old male presented to rheumatology on the inpatient consult service with unexplained headaches, failure to thrive, and persisting elevated acute phase reactants. He was admitted for unexplained fevers three times in as many months, with an unrevealing infectious and malignancy workup. His past medical history was remarkable for a shallow right lateral tongue ulcer that was non-healing despite weeks of acyclovir treatment. Two bitemporal artery ultrasounds did not suggest features of GCA and subsequent temporal artery biopsies failed to show healing or active arteritis. The patient was started on empiric corticosteroids tapered to discontinue over six months in conjunction with tocilizumab. He had rapid normalization of inflammatory markers (prior to tocilizumab initiation), anemia of chronic inflammation, and correction of his serum Na + without need for ongoing fluid restriction. Clinically, his headaches and unexplained weight loss improved and his serial exams showed complete resolution of his tongue ulcer, suspected to be end-organ damage from GCA.

Conclusions: Although the hospitalist service suspected GCA in this elderly patient with headaches, failure to thrive, recurrent fever of unknown origin, and elevated inflammatory markers, they were deterred from this diagnosis by repeat negative bitemporal artery ultrasounds and negative biopsies. This case demonstrates the need to survey for atypical vascular beds of GCA involvement, even in the presence of negative imaging and biopsy results.