[Diffuse disease of elastic tissue and hyperphosphoremia].

Pseudoxanthoma elasticum (PXE) is exceptionally associated with abnormal phosphate-calcium metabolism. On the other hand, significant hyperphosphataemia is present in tumoral calcinosis, with an occasional elastopathy resembling that of PXE. We report here the first case of diffuse elastic tissue disease associated with hyperphosphataemia in the absence of tumoral calcinosis. The patient, a 29-year old Gabonese, had severe arteritis of the lower limbs with linear calcifications of the aorta and major arteries of the limbs. Angioid streaks and calcifications were present in the retinas. The skin appeared to be normal, but histological examination of specimens from flexures showed abnormalities of the elastic tissue with many fibres being broken into small pieces and curled up. In a morphometric study of cutaneous elastic tissue these abnormalities were compared with those observed in a PXE patient and with normal elastic tissue. The abnormalities in our patient and in the PXE patient were similar. Compared to normal elastic tissue, there was a slight decrease in the total number of oxytalan and elaunin fibres. The elastic fibres were distinctly wider, longer and separated from each other by smaller spaces, but not more numerous than normally. The histopathological appearance of an artery removed during bypass surgery was similar to that of a PXE artery. The hyperphosphataemia was due to an increase in tubular absorption of phosphates without abnormalities of parathyroid hormone, or resistance to its phosphaturic effect or any other tubular disorder. It was little altered by aluminium carbonate, and it partially decreased after addition of calcitonin.(ABSTRACT TRUNCATED AT 250 WORDS)