Prolactin (PRL)-secreting tumors are the most common pituitary adenomas in humans. Of all pituitary adenomas, PRL-secreting adenoma (prolactinoma) represent about 40%. It is important to point out that the definition of prolactinomas should include the presence of hyperprolactinemia and emphasize that hyperprolactinemia, especially at levels of less than 200 ng/ml, can be secondary to many other sellar lesions. These issues are important not only in defining the pathophysiology of hyperprolactinemia, but also in choosing appropriate treatments. Magnetic resonance (MR) imaging, especially high resolution MR imaging has replaced CT as the primary imaging modality for pituitary tumors. With contrast media microadenomas are not enhanced immediately and, therefore show up as areas of decreased signal intensity. MR imaging of PRL-secreting macro-adenoma has the advantage of being able to demonstrate the relationship of the tumor to the optic nerve and the cavernous sinus. Therapeutic considerations depend on the associated symptoms and the size of the lesion on pituitary scanning. Surgical resection of adenomas cures in most patients with the disorder. The drop in serum PRL levels to very low levels immediately after transsphenoidal adenomectomy of PRL-secreting microadenoma followed by the gradual recovery of lactotroph responsiveness to stimuli over months. In case of macroadenoma surgical resection cures only about 50%. But surgical resection rapidly improves the vision, decreases the administered bromocriptine (BC) volume and dose not develop a leak of cerebrospinal fluid after packing of the floor ot the sella. Random biopsy and radical resection of diaphragma sella effectively elevate the curative rate, because PRL-secreting adenoma tends to infiltrate.(ABSTRACT TRUNCATED AT 250 WORDS)