SESSION TITLE: Rare Cases with Masquerading Pulmonary SymptomsSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/18/2022 01:35 pm - 02:35 pmINTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare aggressive cancer associated with asbestos exposure. The initial presentation varies; it rarely presents with symptoms related to local invasion. We hereby present a case of MPM presenting with hemoptysis.CASE PRESENTATION: An 80-years-old male patient who is a retired brickmason presents with 2-3 days of hemoptysis. He described cough productive of blood-streaked sputum that progressed to small volume hemoptysis. Medical history is significant for atrial fibrillation on apixaban, and prior tobacco use disorder (40 pack years). He was hemodynamically stable and saturating 88% on room air. Chest CT scan showed multifocal ground glass infiltrates bilaterally with minimal pleural effusions (figure 1). Labs were significant for Hb of 11.1, elevated CRP of 107.6, ESR> 119, negative ANA/ANCAs, and SPEP/UPEP/INR/PTT that were within normal limits. His infectious workup was negative, but he did complete an empiric course of antibiotics. Symptoms were attributed to spontaneous pulmonary hemorrhage in the setting of anticoagulation use. Apixaban was discontinued, hemoptysis improved, and he was discharged home. He presented back 1 week later with exertional dyspnea, ongoing cough, and recurrence of hemoptysis despite being off anticoagulation. Repeat CT scan showed larger pleural effusions, left greater than right, and mild progression of the patchy ground glass opacities (figure 2). A left thoracocentesis was performed with 1L of bloody pleural fluid removed. Pleural studies showed an exudative pleural effusion - RBC 306k, WBC 2.7K (N: 70%, L: 30%), and the cytology was negative. Hospital stay was complicated by re-accumulation of the pleural effusion necessitating chest tube placement. Patient subsequently underwent VATS with pleural biopsies on the left. Given his worsening respiratory failure, patient decided to pursue palliative measures. Pathology revealed malignant pleural mesothelioma, sarcomatoid subtype, invading the lung parenchyma and blood vessels with hemosiderin-laden macrophages suggestive of pulmonary hemorrhage (figure 3).DISCUSSION: The incidence of MPM in the US is estimated to be approximately 3300 cases per year. The most common symptoms are breathlessness (60-90%), chest wall pain (70-90%), and constitutional symptoms such as weight loss and fatigue (30% at diagnosis—usually a late feature). Hemoptysis is a rare presenting symptom (<2%) and it is a result of local invasion of the lung parenchyma. The sarcomatoid subtype of MPM is associated with the poorest prognosis because it is the most invasive and rapidly progressive, and as such likely have a higher chance to be associated with hemoptysis as shown with this patient.CONCLUSIONS: Hemoptysis should be recognized as a rare but possible initial symptom of MPM. It may be suggestive of a more aggressive subtype.Reference #1: anes SM, Alrifai D, Fennell DA. Perspectives on the Treatment of Malignant Pleural Mesothelioma. New England Journal of Medicine. 2021;385(13):1207-18.Reference #2: Marom EM, Erasmus JJ, Pass HI, Patz EF. The role of imaging in malignant pleural mesothelioma. Seminars in Oncology. 2002;29(1):26-35.Reference #3: Murphy DC, Mount A, Starkie F, Taylor L, Aujayeb A. A review of malignant pleural mesothelioma in a large North East UK pleural centre. Pleura Peritoneum. 2020;6(1):20200144.DISCLOSURES: No relevant relationships by Farouk Al ChamiNo relevant relationships by vincenzo cioccaNo relevant relationships by Lee Greenspon, value=Grant/Research SupportRemoved 03/31/2022 by Lee GreensponNo relevant relationships by Patrick Ho SESSION TITLE: Rare Cases with Masquerading Pulmonary Symptoms SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 01:35 pm - 02:35 pm INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare aggressive cancer associated with asbestos exposure. The initial presentation varies; it rarely presents with symptoms related to local invasion. We hereby present a case of MPM presenting with hemoptysis. CASE PRESENTATION: An 80-years-old male patient who is a retired brickmason presents with 2-3 days of hemoptysis. He described cough productive of blood-streaked sputum that progressed to small volume hemoptysis. Medical history is significant for atrial fibrillation on apixaban, and prior tobacco use disorder (40 pack years). He was hemodynamically stable and saturating 88% on room air. Chest CT scan showed multifocal ground glass infiltrates bilaterally with minimal pleural effusions (figure 1). Labs were significant for Hb of 11.1, elevated CRP of 107.6, ESR> 119, negative ANA/ANCAs, and SPEP/UPEP/INR/PTT that were within normal limits. His infectious workup was negative, but he did complete an empiric course of antibiotics. Symptoms were attributed to spontaneous pulmonary hemorrhage in the setting of anticoagulation use. Apixaban was discontinued, hemoptysis improved, and he was discharged home. He presented back 1 week later with exertional dyspnea, ongoing cough, and recurrence of hemoptysis despite being off anticoagulation. Repeat CT scan showed larger pleural effusions, left greater than right, and mild progression of the patchy ground glass opacities (figure 2). A left thoracocentesis was performed with 1L of bloody pleural fluid removed. Pleural studies showed an exudative pleural effusion - RBC 306k, WBC 2.7K (N: 70%, L: 30%), and the cytology was negative. Hospital stay was complicated by re-accumulation of the pleural effusion necessitating chest tube placement. Patient subsequently underwent VATS with pleural biopsies on the left. Given his worsening respiratory failure, patient decided to pursue palliative measures. Pathology revealed malignant pleural mesothelioma, sarcomatoid subtype, invading the lung parenchyma and blood vessels with hemosiderin-laden macrophages suggestive of pulmonary hemorrhage (figure 3). DISCUSSION: The incidence of MPM in the US is estimated to be approximately 3300 cases per year. The most common symptoms are breathlessness (60-90%), chest wall pain (70-90%), and constitutional symptoms such as weight loss and fatigue (30% at diagnosis—usually a late feature). Hemoptysis is a rare presenting symptom (<2%) and it is a result of local invasion of the lung parenchyma. The sarcomatoid subtype of MPM is associated with the poorest prognosis because it is the most invasive and rapidly progressive, and as such likely have a higher chance to be associated with hemoptysis as shown with this patient. CONCLUSIONS: Hemoptysis should be recognized as a rare but possible initial symptom of MPM. It may be suggestive of a more aggressive subtype. Reference #1: anes SM, Alrifai D, Fennell DA. Perspectives on the Treatment of Malignant Pleural Mesothelioma. New England Journal of Medicine. 2021;385(13):1207-18. Reference #2: Marom EM, Erasmus JJ, Pass HI, Patz EF. The role of imaging in malignant pleural mesothelioma. Seminars in Oncology. 2002;29(1):26-35. Reference #3: Murphy DC, Mount A, Starkie F, Taylor L, Aujayeb A. A review of malignant pleural mesothelioma in a large North East UK pleural centre. Pleura Peritoneum. 2020;6(1):20200144. DISCLOSURES: No relevant relationships by Farouk Al Chami No relevant relationships by vincenzo ciocca No relevant relationships by Lee Greenspon, value=Grant/Research Support Removed 03/31/2022 by Lee Greenspon No relevant relationships by Patrick Ho