Contributed by Kent J. Donelan, MD, Brad B. Randall, MD and Paul E. Newby, PA-ASCP
Department of Laboratory Medicine, The Sanford School of Medicine of The University of South Dakota, Sioux Falls, South Dakota.
A 51-year-old man was discovered deceased on the bathroom floor of his home. He had no history of hypertension or other chronic disease. Due to the lack of significant medical history and the unexpected nature of the death, an autopsy was ordered by the county coroner. At autopsy, no apparent thoracic or abdominal cause of death was identified. The decedent did have mild cardiomegaly (525 grams) with left ventricular hypertrophy (2.4 cm). No acute ischemic changes were seen grossly. Sectioning of the coronary arteries showed minimal luminal narrowing and no evidence of acute thrombotic occlusion.
GROSS AND MICROSCOPIC PATHOLOGY
The brain weighed 1300 grams, post fixation. The meninges were clear over the convexities, however, there was diffuse subarachnoid blood accumulation over the base of the brain in a symmetric distribution (Figure 1). A large amount of subarachnoid blood was especially noted near the brainstem at the level of the fourth ventricle foramina. The vasculature was dissected away from the base of the brain. Atherosclerosis was absent and no aneurysms were found on close inspection. There was no evidence of herniation. Coronal sections of the brain showed no gross intra-parenchymal hemorrhage. However, located in the left lateral ventricle and the pineal region/recess of the third ventricle, was an area of accumulated acute blood clot and prominent vessels, suggesting the possibility of a vascular malformation. The hemorrhage extended into the rostral aqueduct of Sylvius, as well as the basal cisterns and adjacent leptomeninges. On cut surface, a central nodule of firm tan-grey tissue measuring 1 cm in greatest diameter was found within the blood cast of the left lateral ventricle.
Microscopically, tissue sections revealed a thick layer of acute subarachnoid hemorrhage surrounding the pineal gland. Embedded within the area were thick-walled muscular blood vessels and small thin-walled venous channels, but they were anatomically unremarkable and thus, there was no evidence of a true vascular malformation. A small cystic structure within the third ventricle showed a papillary epithelial lining with features of non-neoplastic choroid plexus. The surrounding gray and white matter appeared unremarkable. The pineal gland was histologically unremarkable and was partially calcified. Sections of the lateral left ventricle showed acute non-organizing hemorrhage within the ventricle and adjacent choroid plexus. Microscopically, the nodular focus seen grossly in the left lateral ventricle revealed marked chronic xanthogranulomatous inflammation with extensive cholesterol clefts, foreign body reaction, and focal calcifications. A periphery of normal choroid plexus was identified around the nodule (Figure 2). There was evidence of both recent and remote hemorrhage, the latter evidenced by collections of hemosiderin-laden macrophages. Additional representative sections demonstrated evidence of acute hemorrhage within the third ventricle, aqueduct, and subarachnoid space, particularly heavy within the pineal recess.