Keywords: Cryptococcus; Encephalitis; Stereotactic craniotomy
⦁Abstract Cryptococcosis - a fungal infection - mainly caused by Crypto- coccus Neoformans and Cryptococcus Gattii, may affect human central neural system (CNS) with various clinical manifestations. DiagnosisisusuallyconfirmedbydirectCSFmicroscopicexami- nationforencapsulatedyeastsbyIndiainkpreparation.However, sometimes laboratory tests may not be indicative and brain imag- ing with biopsy is necessary to reveal the cause in order to offer theadequatebeneficialtreatmenttopatients.Wepresentacaseof Cryptococcosisdiagnosedbyourdepartmentwhilereviewingthe international literature.
⦁Introduction Cryptococcosis is considered an invasive fungal infection that is caused by Cryptococcus species. Although no human-to-human transmission has been observed, recently cryptococci have been identified to infect and potentially eliminate their human hosts [1,2]. Currently there are two species that commonly cause dis- easeinhumans,C.NeoformansandC.Gattii,mainlyaffectingim- munocompromised patients or patients with pre-existing medical conditions [3]. The aim of this article is to present a case of cryptococcosis diag- nosed by our department while reviewing the international litera- ture. -Citation: Solou M, MRI-Guided Stereotactic Craniotomy to Set the Diagnosis of CNS Cryptococcosis. Case Report and Review of the International Literature. Ann Clin Med Case Rep. 2022; V10(3): 1-3
⦁MaterialsandMethods A previously healthy 44 year old female patient presented withan episode of sudden loss of consciousness. No previous medical history has been reported, including no history of recurrent infec- tions, no travel history outside the state, and was not taking any medications before her admission to the hospital. Her family was healthy.Theepisodewasrepeatedforadditionalthreetimeswith- in the first 24 hours from the onset of the symptoms. Patient was admitted in the hospital and the initial assessment correlated the episodeswithgeneralizedtonic-clonicseizures.Theseizureswere associatedwithpostictusurinaryloss.Onthefifthdayofthehos- pitalization the patient mild temperature elevation (37,5 °C) was added to the symptoms. The initial neurological assessment did not revealed any signifi- cantdeficitwiththeexceptionofincreasedrightsidereflexes.The cognitive evaluation, the cranial nerve function, the motor func- tion and the cerebellar tests were within normal range. The laboratory analysis, including biochemical results were nor- mal(Table1),whiletheinfectionlaboratorypaneltestswereneg- ative as well (Table 2). The patient underwent a brain imaging testing. The CT scan that revealedaminornon-enhancinghypodenselesiononthelefttem- poralarea,withassociatedperifocaledema(Figure1).Inaddition tothattheheadMRIshowedafocallesionofthelefttemporal lobewithlowsignalonT1-weightedsequenceandhighsignalon T2-weighted sequence (Figure 2). The differential diagnosis of the lesion presented in the brain imaging included metastasis and brain abscess. -PatientunderwentaCT-guidedstereotacticminorcraniotomyand removalofthelesionofthelefttemporallobewithinnormalmar- gins. The postoperative recovery of the patient was uneventful.
⦁ Results Pathology on the surgical specimen revealed 3 minor tissue sam- ples, of various sizes ranging from 6mm to 10mm. Microscopic analysis revealed brain grey matter with parts of granulomatous necrotic inflammation, while Cryptococcus fungi were observed within the specimen. The conclusive result of pathology report was Cryptococcus encephalitis. Patient was referred to Infectious Disease Department for further treatment and was eventually dis- charged home after the adequate treatment.
⦁ Discussion ThemajorityofCryptococcusinfectionsinhumansarecausedby C.Neoformans (99%), while the minor remaining 1% is causedbytheC.Gattiispecies[4,5],withendemicvarietyinAustral- ia and New Zealand [3,6]. CNS clinical manifestations vary and might range from headache, increased temperature, seizures, loss or altered level of consciousness, neurological deficits from cra- nialnervesandupperorlowerextremitiesandsignsofmeningitis [3,7–9].Thetimeintervalfromtheonsetoftheinfectionuntilthe development of the clinical manifestations usually includes sev- eral weeks, whereas there cases with sudden onset, and lack of symptomsandsignshavebeenreportedaswell[10].Thediagno- sisisusuallybasedondirectCSFmicroscopicexaminationforen- capsulatedyeastsbyIndiainkpreparation.Histopathologyincas- es of severe CNS infection icludes substantial thickening of me- ninges, diffuse infiltration of Cryptococci spp in the parenchyma, andassociatedinflammationandoedema[11].Thebrainimaging testing in our case, including brain CT and MRI were consistent with the findings reported in the international literature includ- ing the low-density on T1-weighted and high-density lesions on T2-weighted MRI images of the cryptococcomas [12,13]. While the majority of the cases are being diagnosed by blood and CSF laboratory analysis, in our case that the initial results were within normal range, and there was a high indication of CNS infection from the brain MRI findings, the diagnosis was set by surgically removal of the lesion and subsequent histopathology [14,15].
⦁ Conclusion Cryptococcosis is a worldwide high recognizable opportunistic fungal infection that may disseminate to the CNS causing menin- goencephalitis with possible fatal consequences. Primary diag- nosis elaborates the adequate beneficial treatment of the disease that is required for satisfactory outcome. Although the diagnosis is usually set by laboratory blood and CSF test, when these donot prove to be conclusive and the brain imaging testing indicate the possibility of a surgically removable lesion, a navigated cra- niotomy and removal of the lesion should be performed and the subsequenthistopathologicalexaminationcouldpossiblyestablish the diagnosis of Cryptococcus CNS infection.
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Papadopoulos EK. MRI-Guided Stereotactic Craniotomy to Set the Diagnosis of CNS Cryptococcosis. Case Report and Review of the International Literature. Annals of Clinical and Medical Case Reports 2022