Early determination of androgen-responsiveness is important in the management of microphallus.

Of fourteen boys with microphallus who were studied consecutively, nine had hypopituitarism that might otherwise have not been recognised. All fourteen were treated with low-dose, intramuscular testosterone enanthate administered in one or two 3-month courses. In each case, penile size was increased into the normal range without evoking either a significant increase in height velocity or an advancement of skeletal maturation. Before considering surgical sex reversal in infants and young children with microphallus, it is essential to assess whether treatment with intramuscular testosterone will induce clinically significant growth of the microphallus.