Extreme hyperalphalipoproteinaemia in a patient with paraspinal lipoma

Abstract

Introduction Increased HDL-cholesterol (hyperalphalipoproteinaemia) is commonly genetic, but may have secondary causes. An association between multiple lipomatosis and hyperalphalipoproteinaemia has been reported;the mechanism for this is unclear. We report a case of extreme hyperalphalipoproteinaemia in a patient with a paraspinal lipoma. Case report A 69-year-old Cook Island female presented with a large (17×7.5 cm) paraspinal lipoma. Magnetic resonance imaging (MRI) showed no other lipomas. She had the metabolic syndrome, a family history suggestive of lipomas and was on lipid-lowering and antihypertensive therapy. Fasting lipids showed an HDL-cholesterol of 4.9 mmol/L (1.0–2.2), unexplained by secondary causes. Results Lipoprotein electrophoresis confirmed an increased a-lipoprotein band. As expected, apolipoprotein (apo) A-I (the primary apoprotein in HDL), was markedly increased at 3.34 g/L (1.20–2.05);similarly were HDL2 and HDL3 subfractions, with HDL2 predominance. The excised lipoma histology demonstrated benign tissue and normal karyotype. Sections of lipoma and normal adipose tissue were taken for lipoprotein lipase (LPL) activity. Postoperative lipid profiles showed no change in HDL-cholesterol or apoA-I levels. Conclusion We report a case of extreme hyperalphalipoproteinaemia in a patient with lipoma and postulate that LPL enhances the synthesis of mature HDL particles and thus may play a role in lipomatous tissue formation.