Unusual synchronous liver and brain abscesses infected by rare Aerococcus viridians in a patient with pulmonary arteriovenous malformations on FDG PET/CT: A case report and literature review.

RATIONALE: Pulmonary arteriovenous malformations (PAVMs) complicated with multiple organ abscesses is an uncommon manifestation. Because of the low incidence of the disease, F-18 fluorodeoxyglucose positron emission tomography with computed tomography (F-FDG PET/CT) imaging studies for PAVMs complicated with multiple organ abscesses are scarce. PATIENT CONCERNS: We report a case of a 54-year-old man presenting with PAVMs complicated with synchronous multiple organ abscesses founded by F-FDG PET/CT. F-FDG PET/CT revealed tortuous stripes and mass opacities with no significant FDG uptake in the left upper lung lobe. However, hypermetabolic lesions located in the anterior inferior segment of right hepatic lobe [with maximum standardized uptake value (SUVmax) of 10.7], and in the right basal ganglia with SUVmax of 14.1 were found by F-FDG PET/CT. DIAGNOSES: A diagnosis of synchronous liver and brain abscesses infected by rare Aerococcus viridans was determined by tissue culture. INTERVENTIONS: Vancomycin was provided intravenously, and oral linezolidate tablets were prescribed for anti-inflammatory treatment for 1 month. Liver and head magnetic resonance imaging was performed during the follow-up. OUTCOMES: The lesion in the right basal ganglia was reduced, and the lesion in the right liver had disappeared, indicating the lesions were abscesses. LESSONS: The present case indicated that the possibility of abscesses should be considered with patients with PAVMs, and whole-body F-FDG PET/CT is suggested to identify possible accompanying abscesses in multiple organs for PAVMs patients.

Cerebral Abscess Associated With Odontogenic Bacteremias, Hypoxemia, and Iron Loading in Immunocompetent Patients With Right-to-Left Shunting Through Pulmonary Arteriovenous Malformations.

Background: Cerebral abscess is a recognized complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Methods: Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with computed tomography-confirmed PAVMs (including 403 [90.5%] with hereditary hemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression was performed and detailed periabscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier nonoverlapping series. Results: Thirty-seven of the 445 (8.3%) patients experienced a cerebral abscess at a median age of 50 years (range, 19-76 years). The rate adjusted for ascertainment bias was 27 of 435 (6.2%). Twenty-nine of 37 (78.4%) patients with abscess had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. Twenty-one of 37 (56.7%) suffered residual neurological deficits (most commonly memory/cognition impairment), hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events, emphasized potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio, 5.4 [95% confidence interval, 1.4-21.1]); male sex; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Conclusions: Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower oxygen saturation and intravenous iron may be modifiable risk factors.