A 50-Year-Old Woman With Cough and Cystic Lesions Accompanied by Diffuse Interstitial Abnormalities

A 50-year-old woman was admitted to our hospital with a 2-year history of productive cough and intermittent low-grade fever, which had shown only temporary improvement with short courses of antibiotics. Her past medical history was notable for hysteromyoma, treated with hysterectomy 6 years earlier. She did not smoke, did not report any occupational chemical exposures, and reported a family history of cor pulmonale in her father. Approximately 2 years before admission, a thoracic CT scan at a local hospital revealed diffuse cystic lesions with scattered bilateral nodules and calcifications. Bronchoscopy with bronchoalveolar lavage and transbronchial lung biopsy at that time demonstrated scattered inflammatory cells in the interstitium, but did not yield a definitive diagnosis. Subsequently, she was managed symptomatically with close monitoring. One year before admission, her serum creatinine level began to rise from normal levels, eventually peaking at 5.21 mg/dL and accompanied by renal hypertension. A renal biopsy at the same institution suggested acute interstitial nephritis, for which she received a 3-month course of methylprednisolone (initial dose, 40 mg). Unfortunately, neither her chest imaging results nor renal function improved.