Abstract
Benign osteomas occurring in CF-1 mice late in life were observed through 6 consecutive generations, their average incidence being higher in control females (11·5%) than in control males (8·5%) and in treated females(17·4%) and treated males (11·7%). Multiple sites were found in 20% of the cases. The skull was involved in about 90% of untreated osteoma-bearing mice, the limbs in 12·0%, vertebral column in 9·0% and the sacrum and pelvis in 3·0%. In treated mice the skull was involved in approximately 80%, the limbs in 20%, the vertebral column in 12% and the sacrum and pelvis in 8%. The osteomas affecting the skull were represented by small nodules 2-3 mm in diameter, while those found at other sites frequently reached a much larger size (6-10 mm or more). Multiple osteomas with many large nodules at various sites were also observed.