Brain metastasis or nocardiosis? A case report of central nervous system Nocardiosis with a review of the literature

Abstract

Nocardiosis is an infection caused by the gram-positive bacterium Nocardia, which typically manifests as an isolated pulmonary or systemic disease. Of note, Nocardia has a predilection for the central nervous system (CNS) involvement, which is more commonly seen in systemic nocardiosis rather than as an isolated CNS infection. According to the Centers for Disease Control and Prevention, the estimated incidence of nocardiosis is only 500 to1000 cases in the USA every year, with cases mostly found in immunocompromised people, although infection in the immunocompetent may also occur. Here, we present a case of an immunocompromised patient who presented with neurologic symptoms and intracranial lesions initially concerning metastatic disease. Upon further investigation, the patient was found to have CNS nocardiosis with bacteremia. This is an extremely rare presentation given the lack of concurrent pulmonary and cutaneous involvement. The insidious onset and rarity of nocardiosis can result in a delayed or missed diagnosis. Early recognition is crucial as this is a potentially lifethreatening illness. After obtaining adequate culture specimens, empiric treatment must be started expeditiously, keeping in mind the diversity of the Nocardia species and their antimicrobial resistance patterns.

Disseminated Nocardia cyriacigeorgica Infection Disguised as a Metastatic Adrenal Gland Malignancy in a Healthy Patient

“…Transmission of Nocardia typically occurs through inhalation or skin inoculation via penetrating trauma or contamination from soil, water, or dust [ 2 ]. The lungs are the most common site of infection, followed by cutaneous infections [ 15 ].…”

“…In our case, empiric antimicrobial therapy for disseminated nocardiosis with CNS involvement would have commenced with intravenous administration of trimethoprim-sulfamethoxazole, imipenem, and amikacin for a duration of at least six to nine weeks, with the transition to oral antibiotics contingent upon susceptibilities and clinical and radiographic improvement [ 15 , 17 ]. The use of multiple agents upfront is warranted due to the diverse nature of Nocardia species and their varying patterns of antimicrobial susceptibility [ 15 , 17 , 18 ]. The anticipated duration of treatment would have been a minimum of one year, though ultimately determined by the patient's response to therapy [ 17 , 18 ].…”

Case report: From oral infection to life-threatening pneumonia: clinical considerations in Nocardia infection from a case

“…Unlike Candida, which can colonize the human body ( 10 ). Nocardia species often invade the human body from respiratory tract, oral mucosa lesions and skin lesions, and spread to lung, brain and other organs through respiratory tract and blood, which is easy to cause infection ( 11 ). Nocardial is aerobic, and the colonies were smooth and moist when cultured at 37° with general medium, grows into macroscopic colonies within 2–6 days, obtain satisfactory culture results requiring 4–6 weeks ( 12 , 13 ).…”

Case report: Nocardial brain abscess in a persistently SARS-CoV-2 PCR positive patient with systemic lupus erythematosus

“…Since there is a paucity of clinical signs, no serological or biochemical markers of infection, and the radiologic imaging techniques are non-specific, awareness is fundamental for the diagnosis of nocardiosis ( 23 , 24 ). Radiological features of solitary or multifocal ring-enhancing lesions are commonly misdiagnosed as brain metastases, tuberculosis, or bacterial abscess of other etiology ( 25 ).…”