Identify the ODD term in each set and name the CATEGORY to which the remaining three belong:
Exophthalmic Goitre, Simple Goitre, Cretinism, Myxoedema
Topic: Thyroxine deficiency disorders
Answer
Odd one out: EXOPHTHALMIC GOITRE. Category of the others: DISORDERS CAUSED BY A DEFICIENCY (hyposecretion) OF THYROXINE.
All four are thyroid disorders, so the division must be finer than "thyroid" — it is the DIRECTION of the fault.
SIMPLE GOITRE — too LITTLE thyroxine, from a dietary lack of iodine; the gland swells CRETINISM — too LITTLE thyroxine in CHILDREN; stunted growth and mental retardation MYXOEDEMA — too LITTLE thyroxine in ADULTS; puffy skin, weight gain, sluggishness EXOPHTHALMIC GOITRE — too MUCH thyroxine; bulging eyeballs, weight loss, rapid heartbeat
Three are deficiency conditions and one is an excess condition, so exophthalmic goitre is the odd term.
THE TRAP is the word GOITRE appearing in two of the four names, which tempts you to group those two together. Both do involve a swollen thyroid, but for OPPOSITE reasons — and the feature that separates them is the EYES, which bulge only in the hypersecretion form.