A 48-year-old man comes to the clinic with symptoms of ...

A 44-year-old obese woman comes to the clinic for a routine follow up visit for diabetes. Her diabetes has been poorly controlled in the past year and her hemoglobin A1c level was last at 11%. She denies any new problems with her health. On physical examination, you note firm, non-pitting induration on her upper back with a clear cut-off border. ................
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