Unraveling cerebral saccular aneurysm mimics: Case report and review of the literature.

Introduction: Aneurysm mimics, such as an occluded cerebral artery, vascular loops or infundibular dilatations, should be beard in mind when planning a craniotomy for the treatment of an aneurysm. Although ischemic stroke caused by clot migration from an aneurysmal cavity has been described, an ischemic event should raise awareness of potential MCA branch occlusion instead of an aneurysm. Research question: We provided a scaffold that could be used to differentiate other saccular aneurysm mimics. We explored the current literature concerning ACM segment occlusions initially misdiagnosed as a saccular aneurysm. Material and methods: We present the case of a 58 year old female who experienced a subarachnoid hemorrhage. CT angiography could not reveal an underlying aneurysm. She had a medical history of right carotid artery occlusion with secondary ischemic stroke and left spastic hemiparesis. An aneurysm of the right MCA was suspected and she was scheduled for explorative craniotomy. Results: Peroperatively we did not encounter an aneurysm, although a thrombosed branch of the right MCA was noted. The most proximal part of the branch was still patent, mimicking a saccular aneurysm on angiographic records. Discussion and conclusion: Aneurysm mimics can potentially expose patients to unnecessary exploratory craniotomies in the presumptive diagnosis of a saccular aneurysm. MRI 3D-CISS can be a helpful adjunct, since MRA and DSA are frequently not sufficient. Although ischemic stroke can be caused by clot migration from an aneurysmal cavity, an ischemic event should raise awareness of potential cerebral artery occlusion.

Studying the clinical, radiological, histological, microbiological, and immunological evolution during the different COVID-19 disease stages using minimal invasive autopsy.

The WHO defines different COVID-19 disease stages in which the pathophysiological mechanisms differ. We evaluated the characteristics of these COVID-19 disease stages. Forty-four PCR-confirmed COVID-19 patients were included in a prospective minimal invasive autopsy cohort. Patients were classified into mild-moderate (n = 4), severe-critical (n = 32) and post-acute disease (n = 8) and clinical, radiological, histological, microbiological and immunological data were compared. Classified according to Thoracic Society of America, patients with mild-moderate disease had no typical COVID-19 images on CT-Thorax versus 71.9% with typical images in severe-critical disease and 87.5% in post-acute disease (P < 0.001). Diffuse alveolar damage was absent in mild-moderate disease but present in 93.8% and 87.5% of patients with severe-critical and post-acute COVID-19 respectively (P = 0.002). Other organs with COVID-19 related histopathological changes were liver and heart. Interferon-γ levels were significantly higher in patients with severe-critical COVID-19 (P = 0.046). Anti-SARS CoV-2 IgG was positive in 66%, 40.6% and 87.5% of patients with mild-moderate, severe-critical and post-acute COVID-19 respectively (n.s.). Significant differences in histopathological and immunological characteristics between patients with mild-moderate disease compared to patients with severe-critical disease were found, whereas differences between patients with severe-critical disease and post-acute disease were limited. This emphasizes the need for tailored treatment of COVID-19 patients.

Thymoma mimicking an aortic aneurysm: always expect the unexpected.

Thymic epithelial tumours (TETs) are rare lesions that represent less than 1% of all malignancies in adults. Presentation occurs in three ways: asymptomatic, with local thoracic symptoms or with paraneoplastic symptoms. Heterotopic ossifications are rare histological features in neoplasms and non-neoplastic lesions. Here, we present a 49-year-old male patient with a thymoma type B2 mimicking an aortic aneurysm. Alongside the thymoma, a cholesterol granuloma with unusual ossification features was found as well. This clinical presentation and pathological diagnosis are unusual findings.