ATYPICAL PRESENTATION OF BRAIN METASTASES IN PRIMARY LUNG ADENOCARCINOMA

Abstract

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: This case describes an atypical presentation of primary lung adenocarcinoma with multiple brain metastases. It emphasizes the importance of tissue diagnosis to eliminate ambiguity and prevent a delay in appropriate treatment. CASE PRESENTATION: A 68 year-old female with past medical history significant for refractory subglottic stenosis with tracheostomy dependence secondary to prior motor vehicle accident requiring prolonged intubation, nicotine abuse (prior smoker; 112 pack years) presented with recurrent headaches,unintentional weight loss, worsening cough and progressive exertional dyspnea.Examination revealed some neurological deficits. Chest X-ray showed diffuse alveolar opacities in the left lung with lower lung predominance and minimal consolidation in the right lower lobe; these findings were new compared to prior X-ray from 9 months prior (Figure 1).Chest CT revealed diffuse interstitial and alveolar infiltrates,calcified granulomas and lymphangitic carcinomatosis pattern in the left-mid lung (Figure 2). MRI brain was suggestive of old right thalamus lacunar infarct and diffuse multiple ring-enhancing lesions without significant surrounding edema (Figure 3). The differentials of multi-focal infection versus metastatic disease were pursued. Pulmonology, ENT,Neurosurgery and Infectious Disease services were consulted for their input. CSF studies were not consistent with infection or malignancy.Exhaustive serological work up was negative for infection but sputum samples revealed non-tuberculous mycobacterium (rapid grower) for which therapy was initiated. In view of the inconsistent imaging and microbiology findings, tissue biopsy was deemed necessary. As bronchoscopic biopsy would pose a technical difficult given significant tracheal stenosis, brain biopsy was pursued. Biopsy was obtained from the frontal lobe following a stealth-guided craniotomy. Tissue samples were negative for infectious etiology. Pathology was consistent with primary lung adenocarcinoma with molecular profiling demonstrating aneuploidy for ALK and ROS genes. Patient was discharged with medical oncology and radiation oncology follow-up outpatient to initiate treatment. DISCUSSION: This case is unique because of its microbiological and radiological findings. The patient’s chest imaging from approximately nine months prior was completely unremarkable. In addition to the inconsistent timeline, there was no involvement of the right lung on imaging to support the diagnosis of distant metastatic spread; thus making infectious etiology more likely. CONCLUSIONS: Although non-invasive diagnosis of brain metastases is preferred in the majority of cases, brain biopsy may be necessary when imaging is ambiguous. Reference #1: Mota, P.C., Reis, C., Pires, N.F. et al. Lung cancer: atypical brain metastases mimicking neurocysticercosis. Int J Clin Oncol, 16, 746–750 (2011). Reference #2: Choi, H., Choi, S. Multiple Cystic Brain Metastases from Adenocarcinoma Mimicking Cysticercosis. Clin Neuroradiol, 22, 105–107 (2012). Reference #3: Voide, Cathy et al. Cerebral Nocardiosis Mimicking Multiple Brain Metastases in a Patient with Locally Advanced Non–Small-Cell Lung Cancer. Journal of Thoracic Oncology, 9(3), e24 - e26. DISCLOSURES: No relevant relationships by Olaedo Abana, source=Web Response Site Investigator for EMPROVE relationship with Olympus-Spiration Please note: $1001 - $5000 Added 06/15/2020 by Robert Holladay, source=Web Response, value=Grant/Research Support Site Investigator for DAS 181 relationship with Ansun pharmaceutical Please note: $1001 - $5000 Added 06/15/2020 by Robert Holladay, source=Web Response, value=Grant/Research Support No relevant relationships by Louisiana University, source=Web Response