Endocrine Abstracts

Macroprolactinaemia: what is the long-term prognosis? Results from an original series of 55 patients after 10 years clinical follow-up

I Wallace¹, N Satti¹, H Courtney¹, H Leslie², P Bell¹, S Hunter¹, D McCance¹, B Sheridan² & A Atkinson¹

¹Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, UK; ²Regional Endocrine Laboratory, Royal Victoria Hospital, Belfast, UK.

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Macroprolactinaemia is defined as hyperprolactinaemia with a predominance of macroprolactin. It is present in approx 15–36% of cases of hyperprolactinaemia. Controversy exists as to the clinical relevance of macroprolactinaemia with a number of short-term studies demonstrating fewer classical symptoms of hyperprolactinaemia. The long-term prognosis is unknown.

We have previously reported the findings after 5 years follow-up of a cohort of 55 patients with macroprolactinaemia. We have reassessed this original cohort after a median of 9.9 years (range 9–11 years) follow-up and were able to obtain clinical data in 51 patients. (Median age 51 years (range 28–65 years)).

In our report at 5 years follow-up 6 patients experienced headaches, 5 visual disturbance (all had longstanding amblyopia) 13 had oligomenorrhoea (none with amenorrhoea) and 4 had abnormal pituitary imaging (all microadenomas).

At 9.9 years, 7 patients complained of non-specific headaches with no new visual complaints. Four patients had pituitary imaging for a variety of indications with no new pituitary lesions identified. No new menstrual abnormality developed. Eighteen of the group who were not menopausal at presentation developed it at a mean age of 51 years (range 46–56 years). Of 13 patients with oligomenorrhoea, 4 spontaneously developed regular periods, 3 became menopausal and 4 continued to have oligomonorrhoea while 2 were lost to follow-up. There was no new infertility. One patient developed galactorrhoea, which was associated with childbirth. No patients developed an autoimmune condition. Mean prolactin concentration at initial presentation was 1885 mU/l (SE 159.63) and at 9.9 years was1370 mU/l (SE 126.38 P<0.001).

We believe this to be the longest reported follow up of a cohort of patients with macroprolactinaemia. On the basis of our results we propose that macroprolactinaemia is a benign condition and that long term endocrinological review is no longer required.

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Endocrine Abstracts (2009) 19 P279