PET-Diagnostik bei einer Patientin mit Lungenrundherd unklarer Dignität: Riesenzellarteriitis als Ursache der B-Symptomatik

Positron emission tomography (PET) has emerged as a powerful tool in clinical oncology which allows to detect pathological changes in the metabolic characteristics of different tissues. In recent years the PET with the radiopharmakon ¹⁸F-2-fluoro-2-deoxyglucose has proved to be valuable for the diagnostic approach in inflammatory diseases. We report the case of a 69 year old female patient who was admitted for the diagnostic evaluation of a single pulmonary nodule in the right upper lobe which was suspicious for malignancy in the CT scanning. In the last three month the patient lost 13 kg weight, and was complaining about weakness, fatigue, enhanced body temperature up to 101°F and night sweets. In the laboratory findings a microcytic anemia (80 g/L, 74,4 fL), an enhanced C-reactive protein (133 mg/L) and an accelarated ESR of 100 mm Hg/h was remarkable. The pulmonary nodule located in the second segment of the right upper lobe was not accessible in the bronchoscopic examination. Abdominal and cerebral CT scannings showed no pathological findings. In the positron emission tomography an enhanced accumulation of ¹⁸F-2-fluoro-2-deoxyglucose could be detected in the complete aorta and the large-sized arteries of the aortic arch consistent with the diagnosis of a giant-cell arteritis. The suspicious pulmonary nodule of the CT scanning showed no metabolic activity as provable with the PET. The ¹⁸F-FDG PET which is used in the initial staging of newly diagnosed lung cancer and known to be superior to CT in the evaluation of lymph node and distant metastases, is applicable in the diagnostic assessment of chronic inflammatory diseases. As the diagnostic approach in patients presenting with clinical symptoms as fatigue, weight loss, night sweets and fever is often arduous and time-consuming, the PET might become a more central role in the future.