Derm Dx: Progressive yellow skin changes

A 63-year-old patient visits the dermatology clinic because his skin has become yellow. There are a few islands of normal skin, but the majority of his skin surface is covered with yellow patches.

These changes have progressed over the past 3 years. An extensive workup reveals that the patient has a monoclonal gammopathy of undetermined significance (MGUS). His triglyceride, LDL, ...