'Normolipidemic' tendinous and tuberous xanthomatosis

Multiple tendinous and tuberous xanthomas are characteristically associated with hyperlipidemic states. However, normolipidemic tendinous and tuberous xanthomas have been reported in the literature, with normal levels of cholesterol, cholestanol and plant sterols.

To delineate the disorder and to suggest its likely origin, a case of apparently normolipidemic severe tuberous and tendinous xanthomatosis was studied. Several lipoprotein and lipid analyses, clinical tests and histological studies were performed over a period of 5 years in the propositus and his family.

At the first lipid analysis, no quantitative or qualitative alterations of the lipoprotein fractions or of the apoproteins AI, B, CII, CIII, E were detected in the propositus and xanthomatosis was classified as normolipidemic. During the follow-up, the patient showed a nonconstant hypertriglyceridemia and/or hypercholesterolemia associated with the presence of small and dense VLDL and LDL. An increase in apo-B was observed. There was an unusual quantity of conjugated dienes of arachidonic acid in the plasma and in the LDLs of the patient, present only in small traces in the control population. The family study and the long follow-up of the lipid analysis of the propositus were compatible with the diagnosis of familial combined hyperlipidemia.

Our data highlight the importance of a critical review of studies regarding normolipidemic xanthomatosis, since only after an extensive follow-up and sequential analyses of lipoprotein fractions is it possible to exclude the presence of time variables and complex lipoprotein abnormalities.