Acute eosinophilic pneumonia associated with intravesical bacillus Calmette-Guérin therapy of carcinoma in situ of the bladder

Abstract A 71-year-old man with a history of rheumatoid arthritis was treated with intravesical bacillusCalmette-Guerin (BCG) instillation of 80 mg once-a-week for carcinoma in situ . He developed low-grade fever followed by dyspnea and severe hypoxemia. Radiological and laboratory studies revealedbilateral diffuse reticulonodular infiltrates and hypereosinophilia. A lymphocyte stimulation test forBCG was strongly positive. From these findings, a pulmonary hypersensitivity reaction to immuno-therapy was suspected, and therefore, methylprednisolone (500 mg per day) was started. After that,the fever and dyspnea disappeared, the hypereosinophilia was normalised and chest radiographyresults were clear. The present case is the first reported case of eosinophilic pneumonia followingintravesical BCG therapy. Key words acute eosinophilic pneumonia, BCG, bladder cancer. Introduction Intravesical bacillus Calmette-Guerin (BCG) is the mosteffective available treatment for carcinoma in situ (CIS)of the bladder. Although local side-effects of BCGimmunotherapy are usually self-limited, severe systemicreaction and even life-threatening toxicity can occur.