AIDSに合併したクリプトコッカス髄膜脳炎の1剖検例―基底核および小脳病変のMRI画像と病理所見の対応

An Autopsy Case of Cryptococcal Meningoencephalitis with AIDS:Correspondence between MRI and Pathological Findings of Basal Ganglia and Cerebellum

はじめに

　クリプトコッカス髄膜脳炎は非典型的症状で発症する場合があり，しばしば診断に難渋する。また中枢性クリプトコッカス症に伴うMRI所見としては基底核病変が知られているが，病理所見と対比した報告は少ない。今回われわれはAIDSに合併したクリプトコッカス髄膜脳炎で興味深い画像と病理所見を認めたので，文献的考察を含めて報告する。

Abstract

　We reported a 71-year-old male who showed subacute progression in cognitive decline and gait disturbance.　Cystic lesions in the basal ganglia and a high signal in the right cerebellar hemishere were detected respectively on MRI fluid-attenuated inversion recovery (FLAIR) image and diffusion weighted image (DWI) taken at 7 days after admission to our hospital.　Dilatation of the Virchow-Robin space and fresh cerebellar infarction were suspected.　Since an examination of cerebrospinal fluid (CSF) did not reveal any significant features,diagnosis of this patient proved very difficult.　His cellular immunodeficiency was detected by bone marrow aspiration,so he was diagnosed as suffering from acquired immunodeficiency syndrome (AIDS).　Six months after onset,the patient died from sepsis and respiratory failure.　Pathological findings revealed multiple cryptococcus in the cystic lesions of the basal ganglia and cerebellum.　There was little infiltration of inflammatory cells while pathological findings did not demonstrate any AIDS encephalopathy or vascular disorders.　We speculated that subacute progression in cognitive decline and gait disturbance had been caused by cryptococcal meningoencephalitis and secondary normal pressure hydrocephalus (NPH).　Cryptococcal meningoencephalitis in patients with AIDS is often accompanied by normal CSF as a result of cellular immunodeficiency,therefore diagnosis needs to be very careful.　Particular attention needs to be paid to the existence of cryptococcal meningoencephalitis when patients show subacute progression in cognitive decline and cystic lesions in the basal ganglia present themselves on MRI.