Fever of Undetermined Origin During Neoadjuvant Chemoradiotherapy of Gastroesophageal Junction Adenocarcinoma Due to Radiation-induced Liver Disease.

Fever is a common occurrence in cancer patients and often attributed to the disease or treatment complications. Here we present a case of prolonged fever of undetermined origin in a patient undergoing neoadjuvant chemoradiotherapy for gastroesophageal junction (GEJ) adenocarcinoma. An initial detailed work-up remained elusive to the cause of the fever. However, a positron emission tomography (PET) scan prior to the planned surgical procedure identified a lesion in the liver concerning for hepatic metastasis. A prompt biopsy was obtained and revealed radiation-induced liver disease (RILD). Following treatment with corticosteroids, patient's fever completely subsided. While RILD is a recognized complication of radiotherapy, prolonged fever in this setting has not been previously reported. This case illustrates that RILD can sometimes present as prolonged fever. Furthermore, clinicians should be cognizant of radiation necrosis as a potential treatment complication that should be confirmed with a biopsy to avoid missing the chance at potential cure.