Nocardia Brain Abscess Mimicking Metastases in an Immunocompromised Patient

Abstract

The differential for ring-enhancing lesions of the brain is extensive, with patient characteristics, particularly immunologic status, crucial to the clinical plan. In immunocompromised patients with a single ring-enhancing lesion, aspergillosis, toxoplasmosis, and nocardial infections are considered. In the case of multiple ring-enhancing lesions, metastases often supersede opportunistic infections on the differential. We present an unusual case of multiple nocardial brain abscesses mimicking metastases in an immunocompromised patient with a history of narcolepsy.

Keywords: brain abscess; case reports; infections; intracranial mass; lung neoplasms; nocardia.

Figure 1. CT of the chest without contrast with no specific findings

Figure 2. CT of the head without contrast: coronal (A) and horizontal (B) sections with arrows indicating areas of vasogenic edema

Figure 3. MRI of the brain: horizontal (A-G) and coronal (H&I) MRI sections with arrows indicating multiple ring-enhancing lesions

Figure 4. X-ray of the chest

Arrows showing bilateral reticulonodular infiltrates and lobar consolidation indicative of pulmonary nocardiosis.