[Lethal osteogenesis imperfecta. Anatomopathologic (optical and structural) study of 8 autopsy cases].

A pathologic review of lethal osteogenesis imperfecta was performed based in nine cases and mainly concerning eight cases with total postmortem study. One of the cases was classified as type III while all other were of type II. Emphasis is made on the high rate of prematurity, small for date and podalic presentation at birth. In those six cases of lower age lung hypoplasia was present. Well known findings in membranous or enchondral bones were confirmed in this series. Long bones showed characteristic bowings related to the nutrient artery point of entry. Among bone collagen fibres some of them were anomalous in shape or thickness but with normal striation. The only anomaly detected at the cartilaginous epiphysis was the increased wideness of the vascular channels because the existence of loose connective tissue and multivacuolated cells of unknown significance. At the growth plates the vascular channels were too much widened and of abnormal distribution. The proliferative and columnar zones showed poor cellular population and some condrocytes were abnormally vacuolated. The perichondrial ossification groove of Ranvier was absent or underdeveloped in all bones studied coexisting with epiphyseal-metaphyseal deformities. In our present cases, ocular, dental, dermal, cardiac valves and hepatic alterations have been detected. The weight increase and haematopoiesis of the liver was correlated to the hyperplasia and fibrosis of the bone marrow.