Rojas, Carlos A.

Background/Objective Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) may involve the kidney, respiratory tract, skin, or central and peripheral nervous system. Reports of interstitial lung disease (ILD) in AAV (AAV-ILD) have been increasing. Methods We reviewed the medical records of all patients with AAV-ILD between January 1, 2007, and December 31, 2017, and compared their pulmonary involvement to patients with idiopathic pulmonary fibrosis (IPF). Results We identified 24 patients with AAV-ILD: 14 with microscopic polyangiitis, 8 with granulomatosis with polyangiitis, and 2 with eosinophilic granulomatosis with polyangiitis. Perinuclear or myeloperoxidase ANCA was present in 16 cases (66.7%), whereas cytoplasmic or proteinase 3 ANCA was positive in 8 (33.3%). Usual interstitial pneumonia (UIP) was seen in 11 (45.8%), probable UIP in 1 (4.2%), indeterminate UIP in 2 (8.3%), and an alternate diagnosis in 10 (41.7%), and was further characterized as chronic hypersensitivity pneumonitis-like pattern seen in 6 (25%), nonspecific interstitial pneumonia-like pattern in 3 (12.5%), and cryptogenic organizing pneumonia-like pattern in 1 (4.2%). Forced vital capacity and diffusing capacity declined over time in patients with AAV-ILD. When compared with the IPF cohort, patients with AAV-ILD had intermediate survival and speed of lung function decline (3-year survival in AAV-ILD group was 94% vs 69% in IPF). Conclusions Antineutrophil cytoplasmic antibody–associated vasculitis ILD is a progressive and potentially fatal condition. Although most cases in the literature are associated with p-ANCA and positive myeloperoxidase, we found that a third of patients had c-ANCA or granulomatosis with polyangiitis. Our cohort adds experience in this rare manifestation of AAV.

Organizing pneumonia is a recognized complication after external beam radiotherapy of breast and lung cancer but has not been described after radioembolization. A 67-year-old female who underwent ablative trans-arterial radioembolization for the treatment of hepatic metastatic renal cell carcinoma adjacent to the diaphragm presented with computed tomography findings of asymptomatic organizing pneumonia in the lower lobes. A follow-up computed tomography 8 months after conservative management demonstrated near-total resolution of the previous pulmonary parenchymal disease. The patient continues to remain asymptomatic and shows no evidence of residual tumor 10 months after radioembolization.

Proximal interruption of the pulmonary artery (PIPA) is an uncommon developmental anomaly resulting in underdevelopment of the proximal portion of the pulmonary artery with preservation of the intrapulmonary segments. Clinical presentation ranges between an asymptomatic incidental finding to massive hemoptysis. When findings suggestive of PIPA are present radiographically, the diagnosis of PIPA can be definitively diagnosed with computed tomography or magnetic resonance pulmonary angiography. Other imaging modalities, such as nuclear perfusion scan and catheter angiography can help in the diagnosis.