NEW YORK (Reuters Health) – Patients with macroprolactinemia don’t need extensive exams or prolonged monitoring, according to a prospective study.
As long as their monomeric prolactin concentration is normal, patients with this benign variant of hyperprolactinemia don’t require imaging studies, dopamine treatment, or extended endocrine follow-up, the researchers say.
“Hyperprolactinemia is the most common pituitary abnormality,” senior author Dr. A. Brew Atkinson told Reuters Health in an email. “Macroprolactinemia is not at all uncommon and all labs should be screening for it as a routine in the modern era.”
A 2009 report put the prevalence of macroprolactinemia at 3.68%, and these patients make up anywhere between 15% and 46% of those with hyperprolactinemia, the investigators report.
For a median of 9.9 years, Dr. Atkinson and colleagues at Royal Victoria Hospital, Belfast, U.K., followed 51 women, ages 18 to 55, with macroprolactinemia. They describe their patients in a paper published online April 28th in the Journal of Clinical Endocrinology and Metabolism.
“To our knowledge there are no such very prolonged follow-up studies such as ours and it was important to know what happened to this group of patients over an extended period of follow up,” Dr. Atkinson said.
“No symptomatic progression was noted in any of our patients,” the authors write.
The original cohort consisted of 55 women. At presentation, 4 had pituitary adenoma (including one with headache), 6 complained of headache, and 5 had long-standing amblyopia in one eye. (All the others had normal visual acuity.)
Thirteen had oligomenorrhea, one had amenorrhea that resolved after 5 months on bromocriptine, and the others had regular menses or were menopausal, with or without hysterectomy. One had self-limited galactorrhea.
Over the course of follow-up, 7 women had headaches (including one with headaches at baseline). Two had migraine, another had sinus headaches, and in four patients, the cause of the headaches remained undiagnosed. One woman developed hemianopia that resolved within 2 weeks; her neuroimaging results were normal.
Two of the four women with pituitary adenoma had repeat imaging studies. In one, the microadenoma was unchanged. In the other, the lesion could not be found.
Eight women were menopausal at baseline; the other 43 patients were potentially able to conceive. Of the 13 with oligomenorrhea, four resumed normal menstruation, three became menopausal, two were lost to follow-up, and four continued to have oligomenorrhea. No new menstrual irregularities developed.
One patient developed intermittent galactorrhea and one developed the condition after childbirth, which persisted for 2 years despite 6 months’ treatment with a dopamine agonist. This woman was the only patient who received dopamine.
“If monomeric prolactin is normal when calculated via biochemical recovery studies as is now commonly done in many hormone labs, when macroprolactimemia is discovered then no further tests are indicated in the vast majority of patients,” Dr. Atkinson said.
“Our findings add much weight to the view that macroprolactinemia can be considered a benign variant and that imaging investigations, dopamine agonist treatments, and prolonged follow-up are not necessary,” the authors conclude.
J Clin Endocrinol Metab 2010.