A 16-Year-Old Girl Is Brought to the Physician for a Routine

A 16-year-old girl is brought to the physician for a routine health maintenance examination. Her last visit was over a year ago. Menarche was at the age of 12 years; her last menstrual period was 4 months ago. She is on the school's gymnastics team and is currently preparing for an important competition. She is 165 cm (5 ft 6 in) tall and weighs 45 kg (99 lb) ; BMI is 16 kg/m2. Her temperature is 36.8°C (98.2°F) , pulse is 53/min, and blood pressure is 98/64 mm Hg. Examination shows yellowish discoloration of the skin. There are bilateral soft symmetric masses below her mandible. The skin over the dorsal side of her right hand is thickened. Which of the following is the most likely diagnosis?

A) Anorexia nervosa
B) Body dysmorphic disorder
C) Bulimia nervosa
D) Hypothyroidism
E) Irritable bowel syndrome
F) Major depressive disorder