Adefovir-induced Fanconi syndrome associated with osteomalacia

Fanconi syndrome is a dysfunction of the proximal renal tubules that results in impaired reabsorption and increased urinary loss of phosphate and other solutes. The pathophysiology of drug-induced Fanconi syndrome is unclear. Here we report the case of a 36-year-old woman who presented with pain in multiple bones and proteinuria. She had a 7-year history of taking adefovir at 10 mg/day for chronic hepatitis B. Three years previously she had received surgery for a nontraumatic right femur neck fracture, after which she continued to complain of pain in multiple bones, and proteinuria, glycosuria, and phosphaturia were noted. The findings of a light-microscope examination of a renal biopsy sample were normal, but mitochondrial damage of the proximal tubules was evident in electron microscopy. Western blot analysis revealed that the level of serum fibroblast growth factor 23 (FGF23) was lower than in normal controls. After 2 months of treatment, hypophosphatemia and proximal tubular dysfunction were reversed, and serum FGF23 had normalized. This case suggests that direct mitochondrial damage in proximal tubules can cause drug-induced Fanconi syndrome associated with osteomalacia.

Ultrasonic differential diagnosis of stones and carcinomas in the extrahepatic biliary tree

Ultrasonography is a simple, noninvasive and relatively accurate method to differentiate carcinomas from stones in the extrahepatic biliary tree. We analysed ultrasonic findings in 18 stoen cases and 10 carcinoma cases of the extrahepatic biliary tree, which were confirmed by microscopic examination or percutaneous transhepatic cholangiography during the period of May 1980 through May 1982 in Kangnam St. Mary's Hospital. The results were as follows: 1. The number of incidences of multiple echogenecities was 11 out of the 18 stone cases (61.1%) but there were no incidences of multiple echogenecities among the carcinoma cases. Eight cases, four of stoens and carcinomas each , were not detected by sonography. 2. The average diameter of the stones was below 20mm in 13 of the 18 cases (72 .2%) and the number of the stoens over 20mm in diameter was only one of the 18(5.6%), while the number of carcinomas over 20mm was three of the 10 cases (30%). 3. In the 18 patients with stoens, the degree of echogenecity was uniformly high in seven (38.9%) and mixed-moderate in seven (38.9%) . All the carcinomas, however, presented mixed-slight echogenecity. The marginal sharpness was well defined in nine of the 18 stone cases (50%), but only one among the carclnomas. 4. The obstructive site in the biliary tree in the stone cases showed a typical meniscus in 10 (55 .6%), abrupt cutting in four (22_2%) and were indiscernible in four (22.2%). But of the 10 carcinoma cases four (40%) were of abrupt cutting, two (20%) funnel