[Osteoblastoma of 4th cervical vertebrae. Report of a case with hypertrophy of the posterior arch of 3 vertebrae].

The case of a man aged 22 suffering from pain in the right side of the neck is described. Radiographs showed marked hypertrophy of the articular processes of C3, C4 and C5. C-T scanning confirmed this and showed a protrusion into the cervical canal at C.4 level. At operation, this protrusion was found to be due to an osteoblastoma. At first it was thought that the hypertrophy of the articular processes from C.3 to C.5 were due to extension of the osteoblastoma to three levels but later it was concluded that the hypertrophy was a reactive lesion. No other similar lesion has been found in the literature.