A 62-Year-Old Woman With Progressive Dyspnea, Interlobular Septal Thickening, and Ground-Glass Opacities

A 62-year-old White female individual who had never smoked and who had a diagnosis of idiopathic sclerosing mesenteritis in 2006 and antiphospholipid syndrome was referred to the interstitial lung disease clinic in January 2025 for evaluation of progressive dyspnea. In 2009, she experienced pericarditis that required a pericardial window. A PET/computerized tomography/CT scan that was performed at that time revealed diffuse low-grade metabolic activity that involve the mediastinum, abdomen, and pelvis. A bone biopsy from the left iliac crest showed scattered foamy macrophages. Based on a multidisciplinary discussion, she was initiated on mycophenolate mofetil and hydroxychloroquine. Her clinical course remained indolent until 2016, when she presented with new-onset tachypnea and tachycardia. CT chest scan and cardiac MRI raised concerns for constrictive pericarditis, but right heart catheterization revealed concordant ventricular pressures, which ruled out constriction. Her symptoms stabilized until May 2023, when she reported dyspnea. Diuretics provided relief at that time. However, in December 2024, she experienced worsening dyspnea. A cardiac MRI demonstrated evidence of biventricular reduced ejection fraction along with increased infiltration of both atrial walls and interatrial septum by abnormal soft tissue. Chest CT scanning revealed progressive interlobular septal thickening and worsening ground-glass opacities, which raised suspicion for pulmonary involvement. At the interstitial lung disease clinic, she reported modified Medical Research Council grade 2 dyspnea. She denied orthopnea, paroxysmal nocturnal dyspnea, and weight changes and had no relevant occupational or environmental exposures.