Department of Nephrology, Lister Hospital, Herts SG1 4AB, UK
Correspondence and offprint requests to: Dr Mark Little, Renal Section, Division of Medicine, Imperial College, Hammersmith Hospital, London W12 0NN, UK. Email: m.little{at}imperial.ac.uk
Keywords: dialysis-related amyloidosis; computed tomography
Case
A 60-year-old lady, who had been on conventional haemodialysis for 27 years and high flux haemodialysis for 4 years, presented with bilateral buttock pain on sitting. The cause of renal failure was medullary cystic disease and she also suffered from Caroli's disease, hepatitis C, hyperparathyroidism necessitating parathyroidectomy, and ischaemic heart disease. On examination, there were hard, indurated and tender swellings of both buttocks without lymphadenopathy. There were no masses palpable elsewhere. A computed tomography (CT) scan demonstrated ill defined high attenuation signals in both buttocks, greater on the left than the right (Figure 1). Histological analysis of a percutaneous needle biopsy of the region revealed widespread deposition of amyloid (Figure 2). Given the large size of the deposits and their proximity to critical neurological structures, she was managed conservatively with analgesics.
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A prospective post-mortem study found deposition of amyloid in joints in 21% of patients haemodialysed for 2 years, 50% after 7 years and 100% after 13 years [1]. The condition occurs because of the inability of conventional dialysis membranes or peritoneal dialysis to remove the relatively large molecule ß2-microglobulin, the primary component of amyloid deposits [2]. Diagnosis rests on the histological demonstration of amyloid deposits in synovial, fat or tissue biopsy and is supported by the finding of grossly elevated ß2-microglobulin levels of the order of 3050 mg/ml (normal 0.83).
Conflict of interest statement. None declared.
References