A 25-Year-Old Woman Has Had Secondary Amenorrhea for the Past

A 25-year-old woman has had secondary amenorrhea for the past 8 months. She plans to get married soon, and states that she has been trying to lose weight for her upcoming wedding. A urine pregnancy test is negative. The patient is given an intramuscular injection of progesterone. Ten days later she reports that she has had no withdrawal bleeding. Laboratory studies show the following serum levels: $\begin{array}{|l|l|l|}\hline&&\text { Normal range }\\\hline \text { Prolactin } & 10 \mathrm{ng} / \mathrm{mL} & 5-10 \mathrm{ng} / \mathrm{mL} \\\hline \text { Follicle-stimulating hormone (FSH) } & 3 \mathrm{mUJ} / \mathrm{mL} & 5-15 \mathrm{~mL} / \mathrm{mL} \\\hline \text { Luteinizing hormone }(\mathrm{LH}) & 2 \mathrm{mUU} / \mathrm{mL} & 5-22 \mathrm{mLU} / \mathrm{mL} \\\hline \text { Thyroid-stimulating hormone }(\mathrm{TSH}) & 4.1 \mu \mathrm{m} / \mathrm{mL} & 10 \mu \mathrm{mL} / \mathrm{mL} \\\hline \text { Estradiol } & 1 \mathrm{ng} / 24 \mathrm{~h} & 0-14 \mathrm{ng} / 24 \mathrm{~h} \\\hline \text { Cortisol (a.m.) } & 35 \mu \mathrm{gL} & 5-25 \mu \mathrm{dL} / \mathrm{dL} \\\hline \text { Growth hormone } & 10 \mathrm{ng} / \mathrm{mL} & <5 \mathrm{ng} / \mathrm{mL}\\\hline\end{array}$
Which of the following is the most likely diagnosis?

A) Acromegaly
B) Cushing's syndrome
C) Hypopituitarism
D) Primary ovarian disease
E) Weight loss syndrome