A case of resistant Macroprolactinoma

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 167-198-Hypothalamus-Pituitary Development & Biology
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-179
Priyanka Gauravi*1, Jyothi Lekkala2 and Sabyasachi Sen3
1Baystate Medical Centre, Springfield, MA, 2Baystate Medical Center, 3Baystate Medical Center, Longmeadow, MA
Introduction: Prolactinomas are the most common type of pituitary adenomas. Macroprolactinomas commonly cause symptoms due to the excessive production of prolactin as well as complaints caused by tumor mass and compression of neural adjacent structures. Prolactinomas are more amenable to pharmacologic treatment than any other kind of pituitary adenoma because of the availability of dopamine agonists, which usually decrease both the secretion and size of these tumors. For the minority of lactotroph adenomas that do not respond to dopamine agonists, other treatments must be used.

Case Report: A 49 yr old gentleman presented with type 2 diabetes mellitus and was incidentally found to have erectile dysfunction. Patient complained of occasional headaches and also of fatigue. He used to shave once a week and had erectile dysfunction, which did not bother the patient. His erectile dysfunction, fatigue and occasional headaches were attributed to poor glycemic control. Nearly one year later on further investigation, he was found to have a prolactin level of 1,543ng/nl (n 4-15 ng/nl) with 97% monomeric particles. His corresponding testosterone level was 44ng/dl (n 280-800 ng/dl). A MRI of the brain at the same time showed Pituitary macroadenoma with left cavernous sinus invasion. The lesion measures approximately 1.8 x 2.3 x 2.3 cm. Patient was started on cabergoline treatment at 0.5mg po twice weekly.

After 2 and a half yrs of treatment, patients prolactin levels came down to 9ng/ml and free testosterone levels improved to 187ng/dl. However, his MRI of the head showed an almost unchanged macroadenoma with possible necrosis and cystic changes of the mass .Patient continued to have headaches which were mild and occasional. He however has noticed improvement in his weakness and was now shaving three times a week, with no visual field deterioration. Given the chances that sometimes such tumors may have internal bleeding, patient will be referred to neurosurgeon for possible surgical removal of the macroprolactinoma,

Conclusion: Prolactinoma in men are often missed particularly if the patient presents with other morbidities and the symptoms are non specific and not bothersome. It is important to suspect prolactinoma to avoid significant enlargement and possible neurological sequelae. Treatment of patients with lactotroph macroadenomas, no matter how large or how severe the neurologic sequelae, should always be initiated with a dopamine agonist. Higher rates of remission observed in studies with treatment duration longer than 24 months (34 percent) compared with studies with shorter treatment duration (16 percent). Transsphenoidal surgery should be considered when dopamine agonist treatment has been unsuccessful in lowering the serum prolactin concentration or size of the adenoma along with symptoms & signs due to hyperprolactinemia or adenoma size persist following medical treatment.

Nothing to Disclose: PG, JL, SS

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm