A previously healthy 18-year-old woman comes to the physician because of a lump in her neck that she first noticed 1 month ago. She is otherwise asymptomatic. Examination shows a 3- cm left supraclavicular lymph node that is firm and rubbery. The spleen is palpated 3 cm below the left costal margin. The remainder of the examination shows no abnormalities. Laboratory studies are most likely to show which of the following:

A)Decreased serum potassium concentration
B) Increased erythrocyte count
C) Increased serum calcium concentration
D) Increased serum lactate dehydrogenase activity
E) Increased serum thyroid-stimulating hormone concentration