Diffuse pulmonary micronodules with cough, night sweats, and weight loss

SESSION TITLE: Occupational and Environmental Lung Diseases Case Report Posters 1 SESSION TYPE: Case Report Posters PRESENTED ON: 10/10/2023 09:40 am - 10:25 am INTRODUCTION: Silicosis is a potentially fatal lung disease without established treatment. Despite surveillance/prevention efforts, outbreaks are increasing in emerging industries. CASE PRESENTATION: A 30-yr-old man presents from jail for cough, fever, dyspnea for 2 weeks, and night sweats and 25-lb weight loss over months. He was admitted 2 months prior with nausea and emesis. He has history of cirrhosis and takes no medications. Social history is notable for immigrating from Guatemala, heavy alcohol use, incarceration, and occupation in countertop installation. He appears ill, with jaundice, tachycardia and bilateral crackles on auscultation. He rapidly develops hypoxemia.Chest CT shows mediastinal lymphadenopathy and patchy ground glass opacity (GGO) and consolidation on a background of peri-lymphatic vs random micronodules. Comparison with abdominal CT from two months prior shows persistent nodules, mesenteric lymphadenopathy and progression of GGOs and consolidation.Blood/sputum cultures, HIV, and Quantiferon were negative. ANA was + at 1:160. Bronchoscopy with lavage and lymph node biopsy was negative for acid-fast bacilli. Surgical lung biopsy showed dust-laden macrophages, cellular nodules, and subpleural fibrotic nodules with intra-nodular birefringent polyhedral particles (under polarized light) without prominent periodic-acid Schiff (PAS) staining--consistent with accelerated silicosis. DISCUSSION: Differential for diffuse micronodules includes miliary tuberculosis (TB), hematogenous spread of other infection or malignancy, sarcoidosis, silicosis, and hypersensitivity pneumonitis. Concomitant weight loss, cough and dyspnea with social risk factors warrants TB rule-out.Acute silicosis is characterized by cough, dyspnea, weight loss and hypoxemia after weeks to years of high-level exposure. Imaging shows basilar/perihilar GGO and consolidation. Prognosis is poor and progressive massive fibrosis (PMF) can occur in 5 years. Lavage with + PAS stain can be diagnostic of silicoproteinosis. Chronic silicosis occurs with longer low-level exposure, with cough often the only symptom. Imaging shows innumerable nodules that can coalesce into PMF. Pathology shows silicotic nodules. Accelerated silicosis occurs after 10 years of high exposure and shows features of acute and chronic disease. Incidence of silicosis is rising in countertop manufacturing/installation due to absent worker protections and high silica content in artificial stone. Other emerging industries at risk include jewelry, glass, denim, and nanomaterial production. Silicosis can both mimic and increase risk of TB (due to altered macrophage function) and increase risk of autoimmunity. CONCLUSIONS: Differential for diffuse micronodules is broad. Social history and nodule distribution can help narrow this. Accelerated silicosis is a progressive disease with rising prevalence in new industries. TB should be ruled out and followed by annual screening. REFERENCE #1: Leso V, Fontana L, Romano R, Gervetti P, Iavicoli I. Artificial Stone Associated Silicosis: A Systematic Review. Int J Environ Res Public Health. 2019 Feb 16;16(4):568. doi: 10.3390/ijerph16040568. PMID: 30781462; PMCID: PMC6406954. REFERENCE #2: Hoy RF, Jeebhay MF, Cavalin C, Chen W, Cohen RA, Fireman E, Go LHT, León-Jiménez A, Menéndez-Navarro A, Ribeiro M, Rosental PA. Current global perspectives on silicosis-Convergence of old and newly emergent hazards. Respirology. 2022 Jun;27(6):387-398. doi: 10.1111/resp.14242. Epub 2022 Mar 18. PMID: 35302259; PMCID: PMC9310854. DISCLOSURES: No relevant relationships by Krystle Leung No relevant relationships by Joseph Levitt