A 51-year-old male patient with no underlying illness developed a
fever of 38-39 degrees C in June 2009. The
fever persisted for 4 days and, because elevated hepatobiliary
enzymes,
leukocytopenia and
thrombocytopenia were observed, along with chest CT findings of
inflammation of the soft tissues surrounding the left pulmonary artery, the patient was admitted for further examination. Three days after admission, the patient's blood pressure rapidly decreased, resulting in
respiratory failure. Rapid proliferation of the soft tissue surrounding the pulmonary artery and mediastinum was observed on an emergency chest CT.
Malignant lymphoma was initially considered as a possible differential diagnosis; however, neither
pleural effusion nor infiltration of malignant cells could be observed on bone marrow examination. In addition, because the patient responded well to
antibiotics, a diagnosis of acute
mediastinitis was reached. Mediastinal drainage was not performed because the quantity of accumulated fluid was small and because the patient, both in terms of his clinical symptoms and imaging results, showed improvement with the continuation of
antibiotics alone. The patient was ambulatory and was discharged after 24 days of hospitalization. Acute
mediastinitis often follows a rapidly progressive and fatal course without specific symptoms. In the event of unknown
infection following an aggressive course, as in the present case, acute
mediastinitis must be considered with the goal of early diagnosis and treatment.