[Reticulated and necrotic purpura (necrotic angiodermatitis type) due to arterial calcifications in chronic renal insufficiency].
Hyperparathyroidism secondary to chronic renal failure is often accompanied by metastatic calcification with involvement of the skin. The cutaneous lesions appear to be of two types: in the first there was massive calcification of the skin and the subcutaneous tissue; in the second there was necrotic purpura due to intimal proliferation and medial calcification of the cutaneous arterioles. We report the case of a 75-year-old-woman with osteodystrophy who had painful necrotic ulcer and reticulated purpura of the legs (fig. 1 a, b). The new lesions progressed by lateral extension and central necrosis. Biopsy of the skin underlying the purpuric areas revealed intimal proliferation with narrowing of the lumen (fig. 2 a, 3). The most prominent feature was the considerable intimal and internal elastic membrane calcification in several small arteries (fig. 4 a, 5). Von Kossa's stain showed calcium to be present (fig. 2 b, 4 b). There was no calcification of the tunica media. Serum calcium phosphorus product was increased (table I). Tubular reabsorption of phosphate was abnormally low. The serum immunoreactive parathyroid hormone was normal. An iliac crest biopsy revealed the classical lesions of osteodystrophy. Her skin lesions showed spontaneous resolution without parathyroidectomy: the ulcers were healing within two months. A progressive reticulated necrotic purpura has previously been reported in chronic renal failure with secondary hyperparathyroidism. These black ischemic lesions bear a strong resemblance to those accompany atheromatous necrotic angiodermatitis. The metastatic calcification seen in uremia often involves the media; the present case is the first to be reported with intimal calcification.(ABSTRACT TRUNCATED AT 250 WORDS)