WHEN THE ACTINO ACTS UP!

Abstract

SESSION TITLE: Medical Student/Resident Chest Infections Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pulmonary actinomycosis is a rare infection caused by actinomyces, a gram-positive bacterium that normally colonizes the oropharynx, gastrointestinal tract, and female urogenital tract. It is commonly misdiagnosed as an abscess, tuberculosis or malignancy. We describe a case of a 55-year-old man with pulmonary actinomycosis invading thoracic neural foramina and rapidly progressing to acute respiratory distress syndrome (ARDS) and multiorgan failure. CASE PRESENTATION: A 55-year-old man with a 25 pack-year smoking history presented to the hospital with complaints of right flank and upper back pain for 4 weeks. Occupational work exposure included working as a car mechanic, in tobacco factories and insulation production exposing him to asbestos. CT thorax showed a 4.6 x 3.4 cm cavitary mass in the right lower lobe, right pleural metastases, and lymphadenopathy. The mass extended to the right paravertebral region and abutted the right T8-T9 neuroforamina, invading the right posterior 9th rib at the costovertebral junction demonstrated by a lytic lesion. Bronchoscopy with bronchoalveolar lavage was done & the patient and was discharged on empiric Clindamycin for anaerobic infections while cultures were awaited. Outpatient follow up with a chest Xray in 2 weeks was advised. A week after discharge the patient returned to the ER with complaints of worsening dyspnea. He was tachycardic, tachypneic, and hypoxic saturating at 65% on room air. He required high flow nasal cannula oxygenation, was moved to the intensive care unit and was intubated for worsening hypoxia. Chest x-ray showed multifocal pneumonia and new infiltrates on the left mid-lung fields that were absent a week ago. Pending anaerobic cultures from the bronchoalveolar lavage had a heavy growth of actinomyces. Septic shock, severe ARDS, and multiorgan failure had already ensued. The patient's health care proxy decided to withdraw all care and the patient passed away. DISCUSSION: Pulmonary actinomycosis can be challenging to diagnose. Delayed or misdiagnosis as tuberculosis, lung abscess, or lung cancer is common. The average duration of illness before a definitive diagnosis is approximately 6 months(1). In our case, it was misdiagnosed as an anaerobic infection. Radiological manifestations may include a soft tissue mass in the chest wall, empyema, periosteal proliferation, and/or destruction of ribs or vertebrae. In our patient, extensive pulmonary involvement with chest wall invasion should have prompted us to think about actinomycosis. Early diagnosis and treatment could have prevented ARDS and mortality in the patient. The thoracic form requires longer treatment courses compared to other forms(2) CONCLUSIONS: Actinomyces should be on the differential diagnosis for any patient that presents with "invading” pulmonary mass. Prognosis of pulmonary actinomycosis is excellent when it is recognized early and appropriate treatment is given(3). Reference #1: 1. Mabeza GF, Macfarlane J. Pulmonary actinomycosis. Eur Respir J. 2003;21(3):545–51. [PubMed] [Google Scholar] Reference #2: 2. Han JY, Lee KN, Lee JK, Kim YH, Choi SJ, Jeong YJ, et al. An overview of thoracic actinomycosis: CT features. Insights Imaging. 2013;4(2):245–52. [PMC free article] [PubMed] [Google Scholar] Reference #3: 3. Cheon JE, Im JG, Kim MY, Lee JS, Choi CM, Yeon KM. Thoracic actinomycosis: CT Findings. Radiology. 1998;209:229–233. https://doi.org/10.1148/radiology.209.1.9769836. [PubMed] [CrossRef] [Google Scholar] DISCLOSURES: No relevant relationships by Sanya Chandna, source=Web Response No relevant relationships by Sanketkumar Dalwadi, source=Web Response No relevant relationships by Monarch Shah, source=Web Response