HYPERPROLACTINEMIA: GALACTORRHEA-AMENORRHEA SYNDROME - Diagnosis



The diagnosis of hyperprolactinemia should be considered in patients with any of the previously described clinical manifestations, i.e., galactor­rhea, secondary amenorrhea, and impotence. Serum prolactin determinations are available in |p most clinical laboratories and are required to es- jj tablish a diagnosis of hyperprolactinemia. If lev­els are markedly elevated (>150 ng/dl, normal <20), the presence of a prolactin-secreting ad­enoma is highly likely. With lower levels a greater degree of overlap with non-neoplastic causes of hyperprolactinemia occurs. Normal levels of serum prolactin can occur in patients with gal­actorrhea, particularly if the blood sample is drawn at a time between hormone secretory bursts. For this reason, some investigators rec­ommend drawing multiple samples in patients suspected of this disease. Occasionally galactor­rhea can occur with persistently normal serum prolactin levels, presumably as a consequence of increased sensitivity to the hormone.