PLEOMORPHIC CARCINOMA IN THE MIDST OF COVID

ABSTRACT

SESSION TITLE Pathology Identifying Chest Infections Case Report Posters SESSION TYPE Case Report Posters PRESENTED ON 10/17/2022 1215 pm - 0115 pm INTRODUCTION: Pleomorphic carcinoma is a subtype of sarcomatoid carcinomas that represents <1 % of all primary lung neoplasms. This case highlights a recent diagnosis of a patient with pleomorphic carcinoma in the midst of COVID-19 pneumonia. CASE PRESENTATION A 75 year old female with a 180-pack year smoking history presented to the emergency department with dyspnea and chest discomfort. Vital signs significant for oxygen saturation at 93% on room air. The patient had been admitted to the hospital 7 months prior for acute hypoxemic respiratory failure due to COVID-19 pneumonia. At that point, computed tomography (CT) of the chest showed a right lower lobe 5.5 cm juxtapleural lesion measuring fluid attenuation by Hounsfield units without intralesional enhancement. The lesion was initially thought to be secondary to the patient's COVID-19 pneumonia and was not investigated further. The patient was subsequently lost to follow up. Seven months later the patient presented with worsening shortness of breath. Chest CT revealed large right complex pleural effusion with near complete lung collapse. The patient underwent pigtail catheter placement with partial re-expansion of the lung. Pleural fluid analysis showed an exudative effusion with no malignant cells on cytology. Follow-up CT imaging showed a large mass-like area in the right mid and lower hemithorax. Video assisted thorascopic surgery (VATS) decortication and thoracotomy revealed a right lower lobe abscess and empyema. Pathology samples collected during procedure showed malignant cells of sarcamatoid features found in right lung and intraparenchymal lymph nodes. Histology and immunostaining showed a tumor composed of a component of poorly differentiated adenocarcinoma and more than 10% spindle/pleomorphic cells. Immunostaining showed the poorly differentiated adenocarcinoma component was positive for moc 31, Ber-EP4, cytokeratin AE1/AE3, CAM 5.2, lack TTF-1 and p40. The spindle/pleomorphic component was negative for cytokeratins. DISCUSSION: Pulmonary pleomorphic carcinoma (PC) is a rare, poorly differentiated non-small cell lung cancer (NSCLC) that contains at least 10% spindle and/or giant cells or a carcinoma consisting only of spindle and giant cells. PC has poor response to conventional treatments for NSCLC and subsequently poor 5 year survival. It more common in men and smokers. COVID-19 causes a variety of pulmonary radiographic manifestations, including nodules and mass-like consolidations. Superimposed bacterial infections are also common. Our case, however, highlights the importance of serial radiographic monitoring and, when indicated, tissue sampling to rule out alternative explanations for abnormal CT findings. CONCLUSIONS: Appropriate screening and careful follow up of suspicious lung lesions is vital to ensure prompt diagnosis and treatment of lung malignancy. Reference #1 WHO Classification of Tumours Editorial Board. Thoracic Tumours. In WHO Classification of Tumours,Earke 5th ed, IARC Publications, 2021. Vol 5. Reference #2 Ito K, Oizumi S, Fukumoto S, Harada M, Ishida T, Fujita Y, Harada T, Kojima T, Yokouchi H, Nishimura M;Hokkaido Lung Cancer Clinical Study Group. Clinical characteristics of pleomorphic carcinoma of the lung. Lung Cancer. 2010 May;68(2)204-10. doi 10.1016/j.lungcan.2009.06.002. Epub 2009 Jul 3. PMID 19577320. Reference #3 Maneenil K, Xue Z, Liu M, Boland J, Wu F, Stoddard SM, Molina J, Yang P. Sarcomatoid Carcinoma of the Lung The Mayo Clinic Experience in 127 Patients. Clin Lung Cancer. 2018 May;19(3)e323-e333. doi 10.1016/j.cllc.2017.12.008. Epub 2017 Dec 21. PMID 29454534. DISCLOSURES No relevant relationships by Rachel Earle No relevant relationships by Samantha Gillenwater No relevant relationships by Miquel Gonzalez No relevant relationships by Sikandar Khan No relevant relationships by Christopher Lau no disclosure submitted for Jinesh Mehta;