[A plurihormonal adenoma: a case report].
A case of prolactinoma secreting growth hormone is reported. A 32-year-old woman was admitted to our hospital complaining of galactorrhea, amenorrhea and bitemporal hemianopsia. She showed hyperprolactinemia about 500ng/ml and elevated growth hormone level over 10ng/ml without clinical features of acromegaly. Static perimetry represented typical bitemporal hemianopsia better than kinetic perimetry in the early stage of this pituitary tumor. Her visual acuity was 1.0 on the right and 0.02 on the left. MR images showed the intra-and suprasellar mass lesion compressing the optic nerves especially on the left. Because her visual acuity deteriorated rapidly, trans-sphenoidal tumor resection was carried out twelve days after admission. Total removal was achieved. Postoperative MRI showed that the normal pituitary gland had been preserved. The patient's visual acuity recovered to 1.2 on the right and 0.9 on the left, and bitemporal hemianopsia improved remarkably. Postoperative course was uneventful and hormonal functions were normalized. Histological examination showed that the tumor was chromophobe adnoma. The adnoma cells showed immunopositivity for growth hormone, but not for prolactin. Such absence of prolactin granules within cytoplasm might be due to the difference in antigen produced by the adenomatous gland as compared with that produced by the normal gland. Although hyperprolactinemia is often observed in acromegaly, hypersecretion of growth hormone in prolactinoma as was found in this case is very rare in medical literature.