Severe covid-19 pneumonia changes masking lipidemic adenocarcinoma: a diagnostic challenge

SESSION TITLE: Lung Cancer Case Report Posters 13 SESSION TYPE: Case Report Posters PRESENTED ON: 10/09/2023 02:10 pm - 02:55 pm INTRODUCTION: Lipemic adenocarcinoma, formerly known as bronchoalveolar carcinoma, is a rare entity. It has various radiographical presentations, including diffuse alveolar opacities, pulmonary nodules, or areas of ground glass, which are common to several pathological entities, thus making its diagnosis late. We present a rapidly progressive diffuse pneumonic-type lipemic adenocarcinoma (DP-LPA) with adrenal metastasis masked by COVID-19 pneumonia changes. CASE PRESENTATION: A 61-year-old gentleman, a former smoker (30 pack year) with recent COVID-19 pneumonia two months ago complicated by PE, presented to the ED with worsening shortness of breath, productive cough without fever, and AHRF requiring 8 L/min oxygen. Chest CT during COVID revealed extensive ground-glass-type density in the inferior lingula and LLL without lymphadenopathy. Also had 2.4 cm indeterminate left adrenal nodule. Repeat CT 2 weeks later revealed multifocal ground glass opacities in the left upper lobe, lingula, and LLL associated with several small foci of cavitation with mild mediastinal and left hilar adenopathy (Figure 1). He was treated for pneumonia twice in the last two months. CTA chest this visit showed worsening airspace disease and consolidation throughout the left lung. The RUL had a new and increasing airspace disease (Figure 2). There was a background of mild emphysema with increasing left hilar and mediastinal lymphadenopathy. Given these worsening symptoms and imaging, he underwent bronchoscopy with transbronchial biopsies from the LLL anterior and lateral segments which revealed moderately differentiated lung adenocarcinoma with a focal lepidic growth pattern positive for TTF1, CK7, and ROS1 gene rearrangement and negative for CK20, CK5/6, P63, synaptophysin, chromogranin, and CDX2. All cultures and stains from BAL were negative. The PET scan revealed diffuse left lung consolidative opacity with mild hypermetabolism, compatible with biopsy-proven adenocarcinoma, and hypermetabolic left adrenal nodule, compatible with metastatic disease. He was started on combination chemotherapy of carboplatin and pemetrexed. Immunotherapy was delayed while waiting for gene testing. PDL1 staining showed no expression, and EGFR mutation was not detected. DISCUSSION: Lepidic adenocarcinoma is a well-differentiated adenocarcinoma developed along intact alveolar septa without invasion of the stroma, pleura, or vessels. The broad clinical spectrum may lead to rapidly progressive acute respiratory failure. It is diagnosed late due to its atypical radiological presentation, like a solitary nodule or a mass, a localized condensation with air bronchogram, or multifocal and diffuse involvement. Hence, Imaging, mainly ground-glass attenuation. may mimic an infectious etiology including COVID-19. Given infrequent nodal and extrathoracic involvement, typical lepidic adenocarcinoma is generally surgically resectable and associated with better survival. Rarely it present diffuse pneumonic-type involvement associated with worse outcomes, like ours. Bilateral aerogenous limited metastasis has been associated with rapidly progressive acute respiratory failure with ARDS. Our case is unique as it has rapid aerogenous spread involving the bilateral lung, involvement of adenopathy, and distant metastasis to the adrenal. Identifying several molecular abnormalities in lepidic adenocarcinomas is essential because it allows targeted therapies. CONCLUSIONS: In the context of the COVID-19 pandemic, diagnosing lepidic adenocarcinoma can be challenging with atypical radiographic findings and warrants further workup for malignancy in case of recurrent pneumonia, particularly with enlarging lymphadenopathy. REFERENCE #1: 1. Iwata H. Adenocarcinoma containing lepidic growth. J Thorac Dis. 2016;8(9):E1050-E1052. doi:10.21037/jtd.2016.08.78 DISCLOSURES: No relevant relationships by Ayushma Acharya No relevant relationships by Swarup Sharma Rijal No relevant relationships by David Young