Magnetic resonance spectroscopy findings of pyogenic, tuberculous, and Cryptococcus intracranial abscesses

Middle cerebral artery infarction, A rare complication of intracranial cryptococcoma in an immunocompetent patient: A case report and literature review

Background

This report presents the first case of intracranial cryptococcoma arising from the right frontal lobe causing right middle cerebral artery infarction. Intracranial cryptococcomas usually occur in the cerebral parenchyma, basal ganglia, cerebellum, pons, thalamus, and choroid plexus; they may mimic intracranial tumors, but seldom cause infarction. Of the 15 cases of pathology-confirmed intracranial cryptococcomas in the literature, no case has been complicated by middle cerebral artery (MCA) infarction. Here, we discuss a case of intracranial cryptococcoma with an ipsilateral middle cerebral artery infarction.

Case Description

A 40-year-old man was referred to our emergency room due to progressive headaches and acute left hemiplegia. The patient was a construction worker with no history of avian contact, recent travel, or human immunodeficiency virus (HIV) infection. Brain computed tomography (CT) showed an intra-axial mass, and subsequent magnetic resonance imaging (MRI) delineated a large mass of 53 mm in the right middle frontal lobe and a small lesion of 18 mm in the right caudate head, with marginal enhancement and central necrosis. A neurosurgeon was consulted in view of the intracranial lesion, and the patient underwent en-bloc excision of the solid mass. The pathology report later identified a Cryptococcus infection rather than malignancy. The patient underwent 4 weeks of postoperative treatment with amphotericin B plus flucytosine; he then received subsequent oral antifungal treatment for 6 months, and had neurologic sequelae that manifested as left side hemiplegia.

Conclusion

Diagnosis of fungal infections in the CNS remains challenging. This is especially true of Cryptococcus CNS infections that present as a space-occupying lesion in an immunocompetent patient. A Cryptococcus infection should be considered in the differential diagnoses in patients with brain mass lesions, as this infection can be misdiagnosed as a brain tumor.

Proton and Multinuclear Spectroscopy of the Pediatric Brain

Magnetic resonance spectroscopy (MRS) is a valuable adjunct to structural brain imaging. State-of-the-art MRS has benefited greatly from recent technical advancements. Neurometabolic alterations in pediatric brain diseases have implications for diagnosis, prognosis, and therapy. Herein, the authors discuss MRS technical considerations and applications in the setting of various pediatric disease processes including tumors, metabolic diseases, hypoxic/ischemic encephalopathy/stroke, epilepsy, demyelinating disease, and infection.

Cerebral cryptococcoma mimicking glioblastoma

Cryptococcus neoformans and C. gattii cause invasive fungal disease, with meningitis being the most common manifestation of central nervous system (CNS) disease. Encapsulated cryptococcomas occur rarely, predominantly in immunocompetent hosts, usually related to C. gattii Our patient was an immunocompetent man who presented with headache and a large cystic CNS lesion thought to be glioblastoma. Biopsy of a concomitant lung lesion confirmed cryptococcoma and empiric antifungal therapy was started for presumed CNS cryptococcoma. Antifungal therapy failed to shrink the CNS lesion, and surgical excision confirmed C. gattii CNS cryptococcoma. Following surgery he had complete resolution of symptoms. This case highlights that cryptococcoma cannot be distinguished from tumour on clinical or imaging findings. A combined medical and surgical approach is optimal for the management of large or surgically accessible cryptococcomas, as antifungal therapy alone is unlikely to penetrate large lesions sufficiently to lead to a cure.

Cryptococcosis mimicking lung carcinoma with brain metastases in an immunocompetent patient

Cryptococcosis is a fungal infection caused by Cryptococcus spp. that enters the body via inhalation. This ubiquitous yeast has gained notoriety as an opportunistic pathogen in the immunosuppressed population. The authors report a case of a previously-well adult male presented with left-sided weakness. Imaging demonstrated a pulmonary mass and 2 contrast-enhancing intracranial lesions-all features suggestive of a primary lung carcinoma with brain metastases. However, further investigations confirmed disseminated cryptococcosis, without evidence of malignancy. The patient was successfully treated with a course of antifungals. To the authors' knowledge, this is the first reported case of dissemintated cryptococcosis in an immunocompetent adult male, simulating as primary lung carcinoma with brain metastases.

Brain Abscess in a Patient with Rendu-Osler-Weber Syndrome: Value of Proton Magnetic Resonance Spectroscopy

The diagnosis of intracranial focal lesions based on imaging studies is a challenge. In brain abscess, proton magnetic resonance spectroscopy (1H-MRS) is useful to define etiology, differentiating anaerobic from aerobic pathogens and inclusive sterile abscess based on the behavior of certain metabolites. We report a patient with Rendu-Osler-Weber syndrome, pulmonary arteriovenous fistulas, and brain abscesses characterized by brain magnetic resonance imaging (MRI), with a spectroscopy pattern compatible with anaerobic infection.