Department of Diagnostic Radiology and 1 Department of Clinical Immunology and Rheumatology, University of Freiburg, Freiburg, Germany
Correspondence to: T. A. Bley, Department of Diagnostic Radiology, University Hospital Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany. E-mail: bley{at}mrs1.ukl.uni-freiburg.de
SIR, giant cell arteritis (GCA) commonly involves the cranial arteries in a segmental pattern [13]. In the majority of cases, the affection of the temporal arteries can be demonstrated by duplex ultrasonography [4] and is confirmed by biopsy. In a study of 248 patients with proven GCA, however, 23 had a widespread arteritis, and three of these 23 patients presented solely with symptoms due to vasculitis of the lower extremities [5]. Here we present the capacity of high-resolution MRI to depict the unusual vascular involvement in a 65-yr-old man with proven GCA.
He presented with increasing claudication of both legs for the previous 3 months. The medical history was inconspicuous, except for a well-controlled allergic bronchial asthma. No cardiovascular risk factors, such as hypertension, hyperlipidaemia, diabetes and smoking, were present. Just before admission, new onset of a bilateral headache had been interpreted as sinusitis. Additionally, he reported increasing night sweat during the last 3 months. The initial laboratory findings revealed a severe inflammatory response [ESR 85 mm/1st h, CRP 131 mg/l (normal value <5)] but otherwise normal results for the differential blood count and renal and liver function. ANA, ANCA and rheumatoid factor were undetectable. In the physical examination, both dorsalis pedis arteries were impalpable, while the superficial temporal arteries were hard and tender to palpation. Chest X-ray and ultrasound of the abdomen showed no signs of underlying malignant disease. A digital substraction angiography (DSA) was performed, and showed multisegmental stenoses and occlusions of the lower limb arteries and the formation of multiple collaterals (Fig. 1A). High-resolution MRI of the superficial temporal artery (Fig. 1B) and right leg (Fig. 1D) revealed inflammatory changes of the vessel walls, such as thickening and contrast enhancement, underlying the stenoses and obstructions. Suspecting GCA, a biopsy of the right temporal artery was performed. The histology demonstrated a severe mononuclear infiltration of the arterial wall compatible with GCA. The patient was immediately started on a high dose of steroids (1 mg/kg body weight) and aspirin 100 mg once daily. Due to the systemic involvement, empirical treatment with five pulses of monthly intravenous cyclophosphamide was added to the therapy and switched thereafter to oral methotrexate (15 mg/wk). The steroids were gradually tapered to 5 mg/day according to clinical and serological assessment. The initial headache improved within 24 h and the pain-free walking distance increased within 9 months from 25 to 400 m. Angiological re-evaluation after 6 months showed a still decreased but improved perfusion of both dorsalis pedis arteries. After 15 months of therapy with MTX and low-dose steroids, the patient reported no further improvement of the claudication and CRP values were slightly elevated [8 mg/l (normal value <5)]. Re-evaluation by MRI revealed the absence of inflammation in the temporal artery (Fig. 1C) and significantly decreased inflammatory signs in the lower calf arteries (Fig. 1E).
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In our case, the involvement of the superficial temporal arteries and the lower leg arteries was correctly depicted by high-resolution MRI. A control MRI under treatment showed an improvement in vessel wall inflammation. Interestingly, at that time the patient still presented with low systemic inflammation and no further improvement of claudication. Accordingly, the MRI of the lower limb detected residual contrast enhancement. Based on the clinical and laboratory parameters and supported by the MRI finding, immunosuppressive therapy was increased.
This case demonstrates that GCA can be more widespread than commonly expected, including arteries of the lower extremity. Especially for patients without involvement of the temporal arteries or in case of negative biopsy, high-resolution MRI provides excellent additional diagnostic support and will enhance our knowledge of the extent of the arterial involvement in GCA.
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The study group was supported by BMBF grant: BMBF/KNR 01 91/9949.
The authors have declared no conflicts of interest.
References
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