[The periosteum in experimental avian hyperostosis induced by MAV 2-0 myeloblastosis virus. Differential diagnosis from osteopetrosis].

Diaphyseal tibial bones of 11-14-17 th day-old hatched chicks infected with retrovirus myeloblastic MAV 2-0 were examined by conventional optical microscopy. The characteristic lesion is osteoblastic hyperplasia with the development of spongious bone. The new formed bone contains abnormal chondroid tissue. The relation between osseous and cartilaginous tissues in this experimental model is discussed. As connective tissue took part in the constitution of this hyperostosis, this osteopathy may be considered as an hyperplastic, monodermic mesenchymatous, pluritissular tumour. The numerous works concerning the "avian hyperostosis osteopetrosis" are commented.