This paper reports a detailed examination of three lesions of aseptic necrosis of bone occurring in a man who had worked in compressed air eleven years previously. Although two of the lesions were juxta-articular, in neither had the bone collapsed. Histology of only one similar lesion is reported in the literature (McCallum et al. 1966). Necropsy material is considered, together with radiographs and bone scans of the same lesions taken four years earlier. Similar changes have been shown to occur in commercial divers. On the evidence of this case it becomes clear that radiography is limited in its use and that bone scans as an indicator of repair may be open to misinterpretation. There may be a place for operation before the onset of symptoms in these cases of aseptic bone necrosis.

1. Maffucci's syndrome consists of dyschondroplasia (Ollier's disease) in association with cavernous haemangiomata and phlebectasia. Twenty-two cases have hitherto been described.

2. A further case is recorded with autopsy findings showing the characteristic features of the syndrome. Death was caused by a chondrosarcoma of the sphenoid, which led to subarachnoid haemorrhage, cranial nerve palsies, crossed hemiplegia and cavernous sinus thrombosis with almost total pituitary necrosis.