A challenging case of fever of unknown origin (FUO)

Introduction. Fever of unknown origin (FUO) is challenging for physicians as there are more than 200 differential diagnosis of FUO. The diagnosis often requires numerous non-invasive and invasive procedures and sometimes the etiology remains unknown. Clinical case. Our patient is a 24-year-old Caucasian female under contraceptive vaginal ring treatment who presented the first time to the emergency department with fever (38,5°C) and stomach ache. Haematological parameters showed thrombocytosis (728000/mmc) and anemia (10,2 g/dl). Ultrasonography of the abdomen revealed a 4 cm hepatic angioma. She was diagnosed a gastropathy and treated with PPI. Then she was studied deeper because of elevated inflammation markers, persistent thrombocytosis and low-grade fewer combined with fatigue and stomach ache. Despite multiple blood and urine cultures, serology, autoimmune serology, bone marrow biopsy, echocardiography, PET/CT, total body CT, brain MRI scan, transvaginal sonography and gynecological examination no clinical focus could be identified. Esophagogastroduodenoscopy was negative but the histological examination was suggestive of mild celiac disease. Thus, this diagnosis was unlikely because serologic tests and haplotypes DQ2 and DQ8 were negative. Abdomen RMI was suggestive of a 4 cm hepatic adenoma. After surgical resection of the adenoma platelet count normalized and fever disappeared. Conclusions. Hepatic adenoma is an uncommon liver tumor associated with use of oral contraceptive and can be a rare cause of FUO. MRI scan can be a useful tool to detect this tumor.