A 38-year-old man presented for evaluation of lesions on his elbows for 10 years, hands for 1 year, and knees for a few months. The lesions were progressively increasing in number and size and were occasionally mildly tender with firm pressure. He was unaware of similar lesions or known lipid abnormalities in family members. Physical examination revealed numerous pink-yellow firm papules and nodules on the bilateral elbows (Figure 1A) and knees, and linear thin yellow papules on the palmar finger creases. A shave biopsy specimen was taken from a papule on the elbow and sent for histopathologic analysis (Figure 1B). A fasting serum lipid panel was also obtained. Based on the clinical, histologic, and laboratory findings, the patient was diagnosed with an underlying genetic disorder.