Four cases are presented of patients seen in a leper colony in South Vietnam. The patients presented with evidence of osteolysis, arthropathies and severe scarrings of the skin. They were without pain and in generally good health. There were no neurologic or vascular deficit. They had positive serological tests for syphilis. Other known types of osteolysis are discussed including leprosy and the treponemal diseases, and the cases are presented as a previously undescribed entity.