We present the first documented case of biopsy-proven CMV encephalitis with intracranial ring-enhancing lesions on imaging in a SOT recipient.

CMV predominantly affects immunocompromised populations including HIV patients and SOT recipients. Clinical manifestations range from viremia to tissue-invasive disease. Meningoencephalitis, relatively rare, presents with headache, encephalopathy, and/or focal neurologic deficits. Brain MRI typically shows nonspecific T2/FLAIR periventricular hyperintensities and/or ventriculitis, more prominently in HIV-associated cases. CSF quantitative PCR and biopsies with immunohistochemical staining are diagnostic.

A 42-year-old female with end-stage renal disease from IgA nephropathy and subsequent renal transplant in 2018 presented with acute onset fatigue, generalized weakness, and non-productive cough. CT thorax demonstrated multifocal pneumonia, and bronchoalveolar lavage cultures revealed Aspergillus niger for which isavuconazonium was started. 2 weeks later, the patient developed acute encephalopathy and right-sided hemiparesis.

CT head showed bilateral partially hemorrhagic lesions, largest in the right frontal lobe. CT angiogram revealed age-indeterminate left M3 occlusion, however MRI brain without contrast did not reveal a corresponding infarct and displayed scattered foci of restricted diffusion without ADC correlates. Subsequently, MRI brain with contrast demonstrated numerous bilateral ring-enhancing lesions, suggesting an intraparenchymal bacterial or fungal infection. CSF pathogen panel and quantitative assays returned positive for CMV. Biopsy of the right frontal lobe lesion indicated necroinflammatory process and CMV-positive intranuclear inclusions without fungal growth, although brain tissue PCR was negative for both viral and fungal organisms. Patient received a prolonged antimicrobial course for CMV encephalitis and co-existent Aspergillus pneumonia.

While solitary mass lesions have been described with HIV-associated CMV encephalitis, this case represents the first instance of transplant-associated CMV encephalitis with bilateral ring-enhancing lesions spread throughout cerebrum, cerebellum and brainstem on imaging. This should be considered as a differential for SOT recipients presenting with such imaging findings especially in presence of other coinfections, and biopsy should be pursued when indicated.