CASE PRESENTATION: A 36-year-old previously healthy male presented with worsening hemoptysis and exertional dyspnea of 2-week duration. Physical exam showed mild lip cyanosis and fixed splitting of second heart sound. A chest radiograph showed a left lung upper lobe(LUL) opacity and a prominent PA. Chest CAT scan showed a cavitary mass in the LUL, atretic left PA truncated at the hilum, many small left bronchial arteries arising from the aorta, enlarged right PA and pulmonary trunk, and mild aortic coarctation. A V/Q scan showed severely decreased perfusion of the left lung that correlated with atretic left PA. An echocardiogram and a cardiac MRI showed a 14mm secundum type atrial septal defec t(ASD), moderate tricuspid regurgitation, dilated right heart, normal biventricular function, and PA hypertension (PAH). Right heart catheterization showed moderate WHO group-1 PAH. Bronchoscopy guided transbronchial biopsy specimens grew Aspergillus fumigatus consistent with a diagnosis of an aspergilloma. Cultures were negative for mycobacteria. He was started on sildenafil, and voriconazole and underwent ASD closure with tricuspid annuloplasty, and LUL resection. During the procedure, large collaterals from the chest wall to entire left lung parencyma were noted.