Soap bubble appearance in brain magnetic resonance imaging: cryptococcal meningoencephalitis

Abstract

Although cryptococcal infections begin in the lungs, meningoencephalitis is the most frequently encountered manifestation of cryptococcosis among individuals with advanced immunosuppression. As the infection progresses along the Virchow-Robin spaces, these structures may become dilated with mucoid material produced by the capsule of the organism. We report a case of a 24-year-old man with cryptococcal meningoencephalitis in which magnetic resonance imaging showed clusters of gelatinous pseudocysts in the periventricular white matter, basal ganglia, mammillary bodies, midbrain peduncles and nucleus dentatus with a soap bubble appearance.

Fungal colonization of the brain: anatomopathological aspects of neurological cryptococcosis

“…In fact, the commonly observed accumulation of the fungus in the perivascular space supports this hypothesis (Jain et al 2007, Corti et al 2008, Vieira et al 2013. Another potential route for infection of the brain parenchyma includes transit through microvessels.…”

“…This mucoid material is referred to as gelatinous pseudocyst (Tien et al 1991, Mathews et al 1992. HIV-positive patients present multiple gelatinous pseudocysts with abundant C. neoformans cells colonizing the VRS and adjacent areas, which is supposedly caused by the dissemination of the meningeal infection to perivascular spaces (Jain et al 2007, Corti et al 2008, Klock et al 2009, Vieira et al 2013.…”

Cryptococcus gattii-Induced Infections in Dogs from Southern Brazil

“…Pseudocysts seems to occur due to the spreading of CNS cryptococcosis along the distended Virchow-Robin spaces associated with the accumulation of gelatinous material derived from the polysaccharide cryptococcal capsule [37]. Consequently, pseudocysts might be important neurological manifestations of CNS cryptococcosis, which are part of three distinct CNS lesions observed in dogs [14], and are being frequently diagnosed in human encephalitic cryptococcosis [38,39]. The neurological histopathological patterns of canine cryptococcosis have been denominated as: (a) intraparenchymal cryptococcal pseudocysts, (b) meningitis without pseudocysts or parenchymal involvement, and (c) meningoencephalitis without pseudocysts [14]; the neurological presentation observed during this study is consistent with intraparenchymal cryptococcal pseudocysts.…”

Magnetic resonance imaging features of gelatinous pseudocysts in cryptococcal meningoencephalitis

“…Occasionally the meningeal infection can extend along perivascular spaces and give rise to small cysts in the Virchow–Robin spaces and adjacent brain, which term gelatinous pseudocysts [3]. Gelatinous pseudocysts exhibit soap bubble appearance by MRI, with a low to intermediate T1WI signal, a high T2WI signal and a low T2-FLAIR signal [4, 5]. In immunocompromised patients, the enhancements of the cystic lesions and meninges are usually mild or absent.…”