Intracranial abscess due to Mycobacterium avium complex in an immunocompetent host: a case report

Abstract

BackgroundMycobacterium avium complex (MAC) is a ubiquitous pathogen, widely distributed in the environment including water, soil and animals. It is an uncommonly encountered clinical pathogen; primarily causing pulmonary infections in patients with underlying lung disease or disseminated disease in immunocompromised hosts. Sporadically, extra-pulmonary infections have been documented including involvement of the liver, spleen, skin, soft tissue and lymph nodes. Central nervous system (CNS) infections due to MAC are exceedingly rare and carry a poor prognosis. Additionally, such infections are largely reported in patients infected with HIV. Herein we report the first case of intracranial abscess due to MAC in an immunocompetent man with a normal CD4 count and negative HIV status.Case presentationA previously healthy 40-year-old male presented to us with progressively worsening CNS symptoms. The patient’s presentation was uncharacteristic of MAC infection in immunocompetent hosts, as he developed subacute, progressive symptoms that included severe frontal headaches, left eyelid swelling, blurry vision, and diplopia, without any pulmonary or systemic manifestations. Neuroimaging revealed multiple ring-enhancing lesions, which required neurosurgical intervention. MAC was the only pathogen that grew from intraoperative tissue cultures. The patient was subsequently treated with a 12-month regimen consisting of Clarithromycin, Ethambutol, and Rifampin, with successful clinical resolution.ConclusionOur findings indicate that it is important to consider rare infections such as MAC in immunocompetent patients, regardless of atypical symptoms. Despite the severity of this infection, with timely diagnosis effective treatment is available.

Mycobacterium Avium Complex Infection as a Rare Cause of Cerebral Mass Lesion and IRIS in a Patient with AIDS: Case Report and Review of the Literature

“…Advanced HIV/AIDS represents the most common risk factor for MAC infection [ 3 ], and in patients with HIV, the most common presentations are disseminated MAC and localized lymphadenitis. Rarely, MAC may cause other forms of infection, including skin, soft tissue, bone, liver, and spleen disease [ 2 , 4 ]. In contrast, in immunocompetent patients, MAC typically causes chronic, isolated pulmonary infections.…”

“…In our review of the literature, CNS MAC infections are seen primarily in immunocompromised patients ( Table 1 ). Twenty cases of MAC brain abscess have been reported (including the current case), 17 of which occurred in men, with an average age (range) at diagnosis of 45 (33–69) years [ 4–22 ]. More than half of patients were diagnosed with a MAC brain abscess in the absence of known pulmonary or disseminated MAC infection ( Table 1 ).…”

Disseminated Mycobacterium avium Complex Infection Causing Multiple Skull Defects in an Immunocompetent Patient: A Case Report

“…The patient in this case was being treated for hypertension, with no disease-causing immunodeficiency or related drugs administered. The cause of MAC infection in immunocompetent patients remains unclear, although it is assumed that MAC infection is related to variations in the synthesis and action pathways of interferon-γ and interleukin-12 [6]. Multiple recent studies have reported an association between disseminated MAC infection in immunocompetent patients and interferon-γ autoantibodies [7].…”

“…The most common clinical symptoms of disseminated MAC infection include persistent fever, night sweats, weight loss, fatigue, lethargy, and loss of appetite [6]. Other common symptoms include skin and soft tissue infections.…”

“…The patient also showed mild adhesion because of the presence of inflammatory tissue up to the surface of the dura mater through skull defects, whereas infection such as abscess was not observed within the central nervous system (CNS). Although CNS infection due to MAC is very rare in immunocompetent patients, it i s associated with a high mortality rate of 35%-70% [6]. It therefore should be considered as a possibility while diagnosing patients with disseminated infections.…”