Non-Small Cell Lung Cancer with Brain Metastases and Concomitant Listeria Monocytogenes Brain Abscesses

Abstract

Concomitant brain metastases and infectious abscesses is a rare and challenging clinical situation to diagnose and treat, especially given that pathologic evaluation of brain lesions in patients with a history of cancer is often not obtained. In this Teaching Case, we describe our experience managing a patient with de novo metastatic non-small cell lung cancer to the brain. After initial radiotherapy to the brain metastases, the patient developed additional brain lesions, which after multidisciplinary review were presumed to be new metastases based on Magnetic Resonance Imaging (MRI) and treated with radiotherapy. Subsequently, these lesions rapidly progressed and were ultimately determined to be brain abscesses from Listeria monocytogenes, which required a prolonged course of intravenous antibiotics and delayed time to initiation of systemic therapy. Additionally, we summarize the existing literature on concomitant brain malignancies and abscesses, and discuss clinical considerations important to the identification and management of such patients, including radiographic findings and studies to help differentiate between the two entities, steroid side effects, and multidisciplinary evaluation.