Which physical exam finding in a patient could suggest a diagnosis of familial hypercholesterolemia?

The presence of yellow papules on the eyelids, known as xanthelasma, is a classic physical exam finding associated with familial hypercholesterolemia. These yellowish lesions are deposits of cholesterol that can occur in the skin, particularly around the eyelids and tendons, and they indicate elevated levels of circulating cholesterol. Familial hypercholesterolemia is a genetic disorder characterized by significantly high levels of low-density lipoprotein (LDL) cholesterol due to defective or absent LDL receptors, leading to premature atherosclerosis and cardiovascular disease.

The other findings listed do not specifically point towards familial hypercholesterolemia. Bony nodules on the interphalangeal joints could suggest conditions like gout or osteoarthritis rather than a lipid disorder. Hepatosplenomegaly is often associated with liver disease or conditions like lysosomal storage disorders, but is not specifically indicative of familial hypercholesterolemia. Widespread flat hyperpigmented macules may suggest other skin conditions or systemic diseases, but again, are not tied to the lipid abnormalities seen in familial hypercholesterolemia. Thus, the presence of yellow papules on the eyelids stands out as a clear and significant marker for this genetic condition.