Cryptococcoma mimicking a brain tumor in an immunocompetent patient: case report of an extremely rare presentation

ABSTRACT CONTEXT: Central nervous system (CNS) infectious diseases have high prevalence in developing countries and their proper diagnosis and treatment are very important for public health planning. Cryptococcus neoformans is a fungus that may cause several CNS manifestations, especially in immunocompromised patients. Cryptococcal meningitis is the most common type of involvement. Mass-effect lesions are uncommon: they are described as cryptococcomas and their prevalence is even lower among immunocompetent patients. The aim here was to report an extremely rare case of cryptococcoma causing a mass effect and mimicking a brain tumor in an immunocompetent patient. The literature on CNS cryptococcal infections was reviewed with emphasis on cryptococcomas. Clinical, surgical and radiological data on a female patient with this rare presentation of cryptococcoma mimicking a brain tumor are described. Case Report: A 54-year-old female patient presented to the emergency department with a rapid-onset progressive history of confusion and completely dependency for basic activities. Neuroimaging showed a left occipital lesion and neurosurgical treatment was proposed. From histopathological evaluation, a diagnosis of cryptococcoma was established. She received clinical support with antifungals, but despite optimal clinical treatment, her condition evolved to death. CONCLUSIONS: Cryptococcal infections have several forms of presentation and, in immunocompetent patients, their manifestation may be even more different. Cryptococcoma is an extremely rare presentation in which proper surgical and clinical treatment should be instituted as quickly as possible, but even so, there is a high mortality rate.

研究背景：中枢神经系统（central nervous system, CNS）感染性疾病在发展中国家患病率较高，其规范诊疗对于公共卫生规划至关重要。新型隐球菌（Cryptococcus neoformans）是一种可引发多种中枢神经系统病变的真菌，尤其好发于免疫功能低下患者，其中隐球菌性脑膜炎是最常见的感染类型。占位性病变较为罕见，这类病变被称为隐球菌瘤，在免疫功能正常人群中的患病率更低。本研究旨在报告1例极为罕见的隐球菌瘤病例：该病变引发占位效应，在免疫功能正常患者中酷似脑肿瘤。研究回顾了中枢神经系统隐球菌感染的相关文献，重点聚焦隐球菌瘤；同时描述了1例以酷似脑肿瘤的罕见隐球菌瘤为表现的女性患者的临床、外科及影像学资料。

病例报告：1例54岁女性患者因急性起病、进行性加重的意识模糊，且完全无法自理基础日常生活活动前往急诊就诊。神经影像学检查提示左侧枕叶占位病变，遂拟行神经外科治疗。经组织病理学评估，确诊为隐球菌瘤。患者接受了抗真菌药物支持治疗，但尽管采取了最优临床干预方案，其病情仍持续恶化并最终死亡。

结论：隐球菌感染存在多种临床表现形式，在免疫功能正常患者中其表现甚至更为多样。隐球菌瘤是一种极为罕见的临床表现类型，需尽快实施规范的外科与临床治疗，但即便如此，该病仍具有较高的死亡率。