A Sunless Tan

Weakness, nausea, abdominal pain, and a change in her skin color bring a nervous 31 y/o woman to see you. Your Dx?

A 31-year-old woman complains of episodes of weakness, upper abdominal discomfort, and nausea for the past 6 months. She also states that her skin appears to be getting darker even though she spends no more time in the sun than usual. Her hand is seen on the right in the Figure next to that of her treating physician.

What’s your diagnosis?