Disseminated Nocardia Brain Abscess Presenting as Primary Lung Cancer With Brain Metastasis

Abstract

We present a challenging case of disseminated Nocardia brasiliensis infection manifesting as brain and skin abscesses. Nocardia is an important potential pathogen to consider in patients with a relevant travel history to endemic regions or atypical presentations, such as brain and skin abscesses. About one-third of patients with Nocardia infections are immunocompetent, and their symptoms are nonspecific. This case shows the limitations of imaging studies in diagnosing Nocardia brain abscesses, as the patient's non-magnetic resonance (MR) conditional pacemaker precluded MRI evaluation and led to a diagnostic challenge. Therefore, the patient's initial evaluation was presumed to be primary lung cancer with brain metastasis. High clinical suspicion, imaging studies (especially MRI), and tissue biopsy are needed to diagnose this type of brain abscess in a timely manner to prevent further complications.

Keywords: fungal brain abscess; nocardia; nocardia brain infection; nocardia brasiliensis; nocardia spp; skin abscess.

Figure 1. Mass-like enhancing lesion in the left occipital (A) and left frontal lobe (B) with vasogenic edema.

Figure 2. (A) An 18 × 7 mm anterior right upper lobe nodule, (B) an 8 × 7 mm nodule right lung base, and (C) a 5 mm nodule right lung base.

Figure 3. Gram stain showing branching bacillus consistent with Nocardia.