PROGRESSION OF PULMONARY ALVEOLAR MICROLITHIASIS TO PULMONARY HYPERTENSION AND COR PULMONALE

Abstract

SESSION TITLE: Wednesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Pulmonary alveolar microlithiasis (PAM) is a rare disease with less than 600 cases described in the literature. It is characterized by accumulation of calcium phosphate in the alveolar space. (1) Radiographic features are pathognomonic but clinical manifestations are non-specific. We present a case of PAM with progressive deterioration over 20 years leading to pulmonary hypertension (pHTN) and cor pulmonale. CASE PRESENTATION: A Caucasian female presented in her late 20s with pleurisy and based on imaging was diagnosed with sarcoidosis. She was relatively asymptomatic and went without treatment until her 40’s when she developed worsening dyspnea on exertion. PFTs showed mild restrictive lung disease (TLC 3.86L, 78% predicted) with a DLCO of 44%. CT Chest showed diffuse micronodular calcifications, consistent with PAM, not sarcoidosis. Her symptoms progressed over the next 10 years as lung function worsened, showing progressive restriction (TLC 2.97L, 57% predicted) with a DLCO of 4%. Her serial TTEs showed gradual development of right ventricular enlargement, right ventricular hypokinesis, and interventricular septum flattening. Patient underwent right heart catheterization, showing right atrial pressure 10 mmHg, pulmonary artery pressure 66/28 with mPAP 43 mmHg, LVEDP 13 mmHg and cardiac index 3.12 L/m/m2. A trial of tadalafil was attempted without improvement in symptoms and was discontinued. At age 68, the patient presented with acute on chronic hypoxemic respiratory failure with RV failure. CT Chest done demonstrated diffuse calcifications of the lung parenchyma, right ventricular septal bowing, and reflux of contrast into the hepatic veins. Despite aggressive diuresis and supportive care, the patient died from cardiopulmonary failure. DISCUSSION: This case illustrates the progression of PAM with clinical symptoms and radiographic features correlating with decline of pulmonary function, particularly restriction and diffusion capacity. Etiology of PAM remains unclear but has been linked to genetic mutations in SLC34A2 (1). Radiographic characteristics of fine sand-like micronodular calcifications, known as sandstorm, is pathognomonic. We captured the structural effect and strain on the right heart with development of pHTN, likely secondary to chronic hypoxia. Additionally, microliths can irritate alveolar walls, leading to destruction of alveolar capillaries and cause of pHTN. (2) PAM associated pHTN is rarely described as PAM is a rare entity and patients often die from respiratory failure prior to development of pHTN. Treatment is limited to case reports and is not defined (3). CONCLUSIONS: PAM associated with pHTN is infrequently described. Currently, there is still no effective treatment for PAM aside from lung transplant. The treatment of PAM associated pHTN is even more unclear and use of PAH-targeted therapy requires further studies. Reference #1: Lina M. Jönsson Å, Simonsen U, Hilberg O, Bendstrup E. Pulmonary alveolar microlithiasis: two case reports and review of the literature. European Respiratory Review. 2012;21(125):249. Reference #2: Ferreira Francisco FA, Pereira e Silva JL, Hochhegger B, Zanetti G, Marchiori E. Pulmonary alveolar microlithiasis. State-of-the-art review. Respiratory Medicine. 2013;107(1):1-9. Reference #3: Synetos A, Dilaveris P, Gialafos E, Giannopoulos G, Stefanadis C. Severe pulmonary hypertension due to pulmonary alveolar microlithiasis. International Journal of Cardiology. 2006;106(3):396-7. DISCLOSURES: No relevant relationships by Alexandra Haw, source=Web Response No relevant relationships by Ronak Shah, source=Web Response Speaker/Speaker's Bureau relationship with Bayer Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with United Therapeutics Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Gilead Please note: $1001 - $5000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Genentech Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Boehringer Ingelhein Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Honoraria Stock Ownership relationship with Pfizer Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=nothing, I purchased stock Speaker/Speaker's Bureau relationship with Portola Please note: $1001 - $5000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Honoraria Stock Ownership relationship with Portola Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=nothing, I purchased stock Stock Ownership relationship with La Jolla Pharmaceuticals Please note: $1001 - $5000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=nothing, I purchased stock Stock Ownership relationship with Seatle Genetics Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=nothing, I purchased stock PI relationship with United Therapeutics Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Grant/Research Support PI relationship with Actelion Please note: $5001 - $20000 Added 03/13/2019 by Paul Strachan, source=Web Response, value=Grant/Research Support