Marked Hypophosphatemia with Decreased Serum 1,25-Dihydroxyvitamin D in a Patient with Hepatocellular carcinoma Complicating Liver Cirrhosis

Abstract

A 61-year-old male with hepatocellular carcinoma (HCC) complicating liver cirrhosis presented hypophosphatemia progressing with HCC expansion and serum α-fetoprotein elevation. These changes were associated with an increased fractional excretion of phosphate and decreased theoretical phosphate threshold. There was increased nephrogenous cyclic adenosine monophosphate despite normal serum parathyroid hormone. Serum 1,25-dihydroxyvitamin D levels were markedly reduced with normal 25-hydroxyvitamin D levels. There were no symptoms of osteomalacia, however, a slightly increased osteoid seam was elicited on autopsy. The hypophosphatemia could be explained by presumed secretion from HCC of humoral factors which have a phosphaturic effect and also inhibit 25-hydroxyvitamin D-1 α -hydroxylase in renal tubular cells. © 1991, The Japanese Society of Internal Medicine. All rights reserved.