What happened, in summary

A 50-year-old Filipino woman was referred for protein and blood in her urine. Kidney biopsy showed membranous nephropathy, and further investigation was undertaken to look for an underlying infection or cancer. CT identified a persistent ground-glass opacity in the middle lobe of the right lung, an enlarged para-aortic lymph node, and an ovarian mass. The ovarian finding was assessed as a benign cyst, while gastrointestinal endoscopy found no tumor.

A positive T-SPOT test raised concern for tuberculosis, although she had no infectious symptoms and bronchial testing was negative. Follow-up imaging showed that the middle-lobe ground-glass opacity persisted and that a new consolidation had appeared in the right lower lobe. Bronchoscopy could not exclude cancer.

She underwent video-assisted thoracoscopic resection of the right middle lobe and partial resection of the right lower lobe. Pathology found adenocarcinoma in the middle lobe. The lower-lobe lesion was a necrotizing epithelioid granuloma considered consistent with active tuberculosis rather than another cancer site. Antituberculosis treatment began one month after surgery.

Before the operation, her urinary protein loss had risen substantially. After lung resection and tuberculosis treatment, the proteinuria began to fall, the para-aortic lymph nodes became smaller, and the membranous nephropathy reached complete remission after five months. The relative contribution of cancer removal, infection treatment, and spontaneous renal recovery could not be determined.

The lung cancer and tuberculosis were kept clinically separate. The para-aortic nodes were considered more likely related to tuberculosis than metastatic adenocarcinoma, and no distant spread was confirmed.