D109-11 Pulmonary Capillary Hemangiomatosis Without Evidence of Pulmonary Hypertension

Abstract Introduction Pulmonary Capillary Hemangiomatosis (PCH) is a rare pulmonary vascular disorder characterized by abnormal proliferation of capillary-like vessels within the lung parenchyma. It is typically associated with pulmonary hypertension and restrictive lung disease, often leading to progressive respiratory failure 2. Symptoms such as dyspnea, fatigue, and dry cough are nonspecific and frequently mimic other pulmonary conditions, making diagnosis challenging 3. Case Presentation A 73-year-old male with hairy cell leukemia and paroxysmal atrial fibrillation presented with dyspnea, diaphoresis, fever, and chills. He had previously been diagnosed with amiodarone-induced interstitial pneumonitis and started on prednisone and bactrim after BAL showed hemosiderin-laden macrophages without foamy macrophages. On admission, he required 2 L nasal cannula to maintain oxygen saturation 90%. Vital signs showed a heart rate of 125 bpm and temperature of 100.5 °F. Labs revealed WBC 21.3 × 109/L, BNP 300 pg/mL, and troponin I 0.42 ng/mL. Chest CTA demonstrated interstitial opacities with mosaic attenuation, normal pulmonary artery caliber, and massive splenomegaly. Infectious workup was negative, including Streptococcus pneumoniae and Legionella urine antigens, respiratory viral panel, and serum CMV PCR. Bronchoscopy showed no anatomic abnormalities; BAL was positive for yeast and HSV PCR. Acyclovir provided minimal improvement. Echocardiogram revealed a mildly dilated right ventricle with mildly reduced systolic function and estimated right atrial pressure 15 mmHg (TAPSE 1.5 cm). Lung cryobiopsies revealed PCH with mild obliterative bronchiolitis and intercapillary lymphoid infiltrates consistent with hairy cell leukemia; iron staining again showed hemosiderin-laden macrophages. Right heart catheterization demonstrated normal pulmonary artery pressures (27/10 mmHg, mean 16 mmHg), excluding pulmonary hypertension 1. Discussion PCH’s etiology remains unclear but may occur with pulmonary arterial hypertension or interstitial lung disease 2. BAL may show hemosiderin-laden macrophages from occult alveolar hemorrhage. High-resolution CT typically demonstrates diffuse, bilateral ground-glass opacities, though definitive diagnosis requires biopsy. Management is supportive, focusing on symptom control and comorbidity treatment. In patients with pulmonary hypertension, traditional vasodilatory agents can be used, however, they may be at increased risk of pulmonary edema compared to other causes of pulmonary hypertension. Lung transplantation remains the only definitive therapy; early referral is recommended due to potential rapid progression 3. Conclusion This case illustrates biopsy-proven PCH without pulmonary hypertension—a rare presentation, as it is typically associated with group 1.5 PAH 1. Early recognition, even in atypical cases, is essential for appropriate management and prognosis. This abstract is funded by: None