Numerous Weibel-Palade bodies in a calcified chronic subdural haematoma

A 75-year-old man who had a calcified chronic subdural haematoma is reported with reference to the role of Weibel-Palade (W-P) bodies. He developed progressive dementia and a disturbance of gait. Computerized tomography demonstrated a large subdural haematoma bordered by a calcified rim. A frontoparietal craniotomy was performed to reveal approximately 100 g of paste-like, muddy blood clot. The thick capsule consisted microscopically of fibrous tissue with deposits of calcium, haemosiderin and cholesterin. The calcified outer membrane contained a small number of proliferating capillaries which conceivably contributed to the leakage of blood. The fine structure of these capillaries showed endothelial sprouts with numerous W-P bodies. This finding suggested some correlation between W-P bodies and vascular proliferation. It is noteworthy that an active vascular proliferation was observed even in the healed tissue with calcification.