Pituitary macroadenomas associated with hyperprolactinaemia: immunocytochemical and in-situ hybridization studies.
OBJECTIVE
We have assessed whether in-situ hybridization for prolactin messenger RNA (mRNA) provides additional information for the classification of pituitary macroadenomas associated with hyperprolactinaemia.


METHODS
In-situ hybridization for PRL mRNA was performed on surgical biopsies of pituitary adenomas and the results correlated with serum PRL levels and PRL immunoreactivity.


METHODS
Twenty-one patients (11 men, 10 women) were included; five had normal serum PRL levels, 11 mild hyperprolactinaemia (less than 3000 mU/l) and five marked hyperprolactinaemia (greater than 3000 mU/l).


METHODS
Immunocytochemistry for PRL and in-situ hybridization for PRL mRNA were performed on surgical biopsies.


RESULTS
Immunoreactivity for PRL was detected in tumours from all patients with serum PRL greater than 3000 mU/l and in one of 11 patients with mild hyperprolactinaemia. Positive signal for PRL mRNA was detected in four of five immunopositive cases studied, in a further two cases with mild hyperprolactinaemia, and in one tumour associated with normal serum PRL level.


CONCLUSIONS
In-situ hybridization provides evidence of PRL gene activation in the absence of immunoreactivity for prolactin. This may reflect low levels of hormone storage or defective translation of the mRNA.
McNicol
A M
AM
University Department of Pathology, Royal Infirmary, Glasgow, UK.
Walker
E
E
Farquharson
M A
MA
Teasdale
G M
GM
D000236:Adenoma / Q000737:chemistry / Q000145:classification / Q000150:complications / Q000235:genetics*; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000209:etiology / Q000235:genetics*; D007150:Immunohistochemistry; D008297:Male; D015336:Molecular Probe Techniques; D010911:Pituitary Neoplasms / Q000737:chemistry / Q000145:classification / Q000150:complications / Q000235:genetics*; D011388:Prolactin / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*
D012333:RNA, Messenger; D011388:Prolactin