Diagnosis of Tendinous Xanthomas Questioned

To the Editor:

The photos accompanying the dermatology quiz presented by Dr East and colleagues in the April 2004 issue of the journal (page 33) show tuberous xanthomas, not tendinous xanthomas, as suggested by the authors (Figures 1, 2). Tendinous xanthomas are restricted to the tendons and show no skin discoloration or overlying lesions. It is not unusual to see both tendinous and tuberous xanthomas in homozygous familial hypercholesterolemia. In the images the authors provided, we can almost see a tendinous xanthoma in the extensor tendon of the middle finger shown in Figure 2. Heterozygotes commonly have tendinous xanthomas but not tuberous xanthomas. Figures 3 and 4 are examples of tendinous xanthomas, and Figure 5 illustrates tuberous xanthomas.

Professor of Internal Medicine, University of Utah, Cardiovascular Genetics

Paul N. Hopkins, MD, MSPH,

The Authors Reply:

In the images we provided (Figures 1, 2), the xanthomas referred to as tendinous xanthomas are attached to extensor tendons of the hand. We agree that the interdigital lesions would be accurately described as tuberous. This is an unusual case because the patient is African American. In the United States, homozygous familial hypercholesterolemia is even less often seen and described among African American populations than in white populations. It is indeed unusual to have discoloration of tendinous xanthomas; however, we believe that this is the case in this patient because of her complexion and the chronicity of her disease. She does have quite impressive tuberous xanthomas on the processus olecrani.

Honey E. East, MD, James G. Bennett, MD, Dena W. Jackson, MD, Michael R. McMullan, MD, University of Mississippi Medical Center