Atypical posterior circulation strokes: a case-based review of rare anatomical variations involved.

The circle of Willis is a very important vascular mechanism of protecting against cerebral ischemia, especially when circulation within the main arteries irrigating the brain is somehow impeded. As result of congenital malformation arising early in embryonic development, the fetal-type posterior circle of Willis remains as such during the rest of one's life. Consequently, the posterior cerebral artery (PCA) becomes a branch of the internal carotid artery (ICA), rather than of the basilar artery (BA). Furthermore, the rest of collateral circulation, between the anterior and the posterior regions of the brain, is also negatively affected (e.g., leptomeningeal vessels). The anatomical variant represented by the artery of Percheron (AOP) has its origin on one of the PCAs, supplying singlehandedly both paramedian areas of the thalamus (right and left) and posterior regions of the midbrain. In the present study, we report a case of bilateral thalamic infarction with midbrain involvement, where the correct diagnosis was made retrospectively using computed tomography (CT) scan, magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI) and three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA).

Giant abdominal lipofibroma - case presentation.

Abdominal lipomas are benign mesenchymal tumors of mature fatty tissue that may appear at any age. We present the case of a 58-year-old patient with a cardiovascular pathology, who presented with diffuse abdominal pains, asthenia, anterior thorax pains and palpitations, abdomen increase, symptoms that had an insidious onset. The clinical and imagistic examinations suggested the diagnosis of giant abdominal lipoma. The surgical intervention allowed the excision of an encapsulated tumor, of 250÷220÷230 mm, relatively well encapsulated, with a macroscopic aspect of section adipose tissue, with hard whitish areas, with a 12.3 kg weight. The histopathological examination confirmed the diagnosis of lipofibroma.

Multifocal and multicentric low-grade oligoastrocytoma in a young patient.

Multiple primary central nervous system tumors are rarely seen in clinical practice and reported in the literature. The pathogenesis of multicentricity of primary tumors of the central nervous system still remains a debate, this pathology being found in almost two percent of reported tumor cases. Multifocal tumors are often described within the same hemisphere and supposed to be disseminated along the white matter tracts. On the opposite, multicentric tumors are found in the other hemisphere in subtentorial structures and are considered synchronous. We illustrate here the case of a young man admitted for symptoms of intracranial hypertension, diagnosed with multifocal and multicentric low-grade oligoastrocytoma with particular evolution and imagistic appearance.