C63-03 Successful Long-Term Pharmacotherapy in Pulmonary Capillary Hemangiomatosis With Resolution of Ground-Glass Opacities

Abstract Introduction Pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis (PCH) are rare subtypes of pulmonary arterial hypertension characterized by venous remodeling and capillary proliferation. Prognosis is typically poor, effective pharmacotherapies are not established, and vasodilators may precipitate pulmonary edema. Histological confirmation is often avoided because of procedural risk, so diagnosis relies on clinical and radiologic features. We report a case of systemic-sclerosis-associated PCH in which medical therapy resulted in disappearance of characteristic bat-wing ground-glass opacities (GGO) and long-term hemodynamic stability. Case Report A 48-year-old woman with intermittent follow-up for inflammatory arthritis developed progressive exertional dyspnea. Evaluation revealed systemic sclerosis complicated by pulmonary hypertension. Chest computed tomography demonstrated patchy bat-wing GGO, interlobular septal thickening, and pleural and pericardial effusions (Panels A and B). Echocardiography estimated a pulmonary artery systolic pressure of 75 mmHg. Laboratory tests showed anemia (Hb 10.3 g/dL), mild hepatic and renal dysfunction, markedly increased D-dimer (10.78 μg/mL) and NT-proBNP (1957 pg/mL), and a high-titer antinuclear antibody (1:1280) with negative anti-Scl-70, anticentromere, and anti-RNA polymerase III antibodies. Ventilation-perfusion scanning showed no mismatched defects. Pulmonary function testing revealed a restrictive pattern (VC 1.73 L, %VC 56.3%) and reduced diffusing capacity (%DLCO 42.3%). Right heart catheterization confirmed precapillary pulmonary hypertension (mean pulmonary arterial pressure mPAP 35 mmHg, pulmonary artery wedge pressure 5 mmHg, cardiac index CI 2.57 L/min/m2, pulmonary vascular resistance PVR 8.0 Wood units). PCH associated with systemic sclerosis was clinically diagnosed. Rituximab failed to improve hemodynamics (mPAP 37 mmHg). With oxygen-dependent respiratory failure, dobutamine and diuretics were started. Imatinib was initiated for PCH, followed by tadalafil, then switched to sildenafil because of edema. Macitentan was subsequently added with caution. Imatinib and sildenafil were discontinued due to paralytic ileus and eosinophilia, respectively, and selexipag was initiated. The patient stabilized and was discharged. One year later, mPAP improved to 21 mmHg and remained 19 mmHg at three years. Follow-up CT demonstrated complete resolution of GGO and septal thickening (Panels C and D). No EIF2AK4 mutation was detected. Discussion This case demonstrates radiologic disappearance of PCH-consistent lesions and sustained hemodynamic improvement under sequential targeted therapy. As vasodilators have limited efficacy and carry a risk of pulmonary edema in PCH, imatinib likely contributed to regression of capillary lesions, consistent with reported PDGF overexpression in PCH. Early imatinib exposure may have contributed to regression of capillary proliferation. Conclusion Targeted medical therapy, including imatinib, macitentan, and selexipag, may achieve clinical and radiologic remission in systemic-sclerosis-associated PCH. This abstract is funded by: None