Rare Presentation of Fever of Unknown Origin: A Diagnostic Challenge.

We present the case of a 49-year-old postmenopausal female patient with recurrent urinary tract infections, chronic pelvic pain, and persistent systemic symptoms, including fever, hypotension, and leukocytosis, admitted five times over a three-month period. Despite extensive antimicrobial treatment, imaging revealed retroperitoneal and gastrohepatic lymphadenopathy with pancreatic fat stranding, raising suspicion for malignancy or disseminated fungal infection. The patient's complex presentation, occupational exposure, past gynecologic procedures, and linguistic barriers compounded the diagnostic challenge. This case met the classic criteria for fever of unknown origin (FUO) and emphasizes the need for a multidisciplinary approach to rare pelvic infection presentations in postmenopausal women.