Long-term survival and onset of granulomatous pneumonia after lung metastasectomy in a patient with non-muscle-invasive bladder cancer

This case report describes a first case of granulomatous pneumonia occurring at the same site of the previous lung metastasectomy in a patient with high-grade non-muscle-invasive bladder cancer (NMIBC), which was treated with bladder preservation therapy despite multiple recurrences and failure of intravesical bacillus Calmette-Guẻrin (BCG) therapy.

We report a 52-year-old woman who underwent transurethral surgery and BCG therapy for pT1, G3 bladder cancer. Although cystectomy was recommended after BCG failure, the operation was not performed because of the patient’s wish for bladder preservation. Eighteen months after the first surgery, computed tomography (CT) revealed solitary lung mass. Partial lobectomy which the patient underwent after chemotherapy revealed G3 metastatic urothelial carcinoma. Three years after lung metastasectomy, CT revealed lung mass at the same site of the previous lung metastasectomy. Dynamic contrast-enhanced magnetic resonance imaging showed the significantly enhanced lung mass, which indicated lung metastasis. However, lobectomy of the remnant lobe revealed that the lung mass was granulomatous pneumonia. Although no additional specific treatment was carried out, the patient remains free of disease for 53 months after surgery.

Lung metastasis from NMIBC rarely occurs. Our case report confirms that lung metastasectomy in highly selected patients may contribute to long-term disease control. Moreover, our case report suggests that mycobacterial lung infections along the staple-suture line rarely occur, and percutaneous biopsy should be considered under these circumstances to avoid the unnecessary operation.