[Prolactin microadenoma in men. Study of 14 cases].

Macroprolactinomas have been well documented in men over the past several years. By contrast, to the best of our knowledge, there have been no reports of microprolactinomas in men. We describe here 14 cases of microprolactinomas occurring in male patients (14 to 53 years old) and discovered on the basis of endocrine symptoms. Nine patients complained of impotence and/or decreased libido, 8 had gynecomastia with or without galactorrhea, 1 had undergone incomplete puberty. All patients had hyperprolactinemia (225 +/- 65 micrograms/l, mean +/- SEM, N less than 13 micrograms/l); plasma testosterone levels were low in 9 (162 +/- 33 ng/dl, mean +/- SEM; N = 308 - 876 ng/dl), while plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels and their responses to LH-releasing hormone (LHRH) were normal in all cases. Among the 14 patients, 12 had no hypopituitarism and 2 had only partial corticotrope insufficiency; none had visual disturbances and only one complained of headaches. The sella turcica was normal in size and shape in 2 cases but a double floor and/or a thinner part of the floor was observed in 12. CT scan of MRI demonstrated in all cases an intrasellar microadenoma with a mean size of 7 mm (range, 3 to 10 mm) and no preferential localization. One patient was treated with bromocriptine, while the others underwent surgery via the transsphenoidal route. Immunocytochemistry demonstrated immunoreactive-prolactin (IR-PRL) cells in all the adenomas. Surgery resulted in normalization of plasma PRL in 11 of the 13 patients and in lowering PRL levels in the others 2.(ABSTRACT TRUNCATED AT 250 WORDS)