COEXISTENCE OF GROWTH HORMONE-SECRETING PITUITARY-ADENOMA AND INTRACRANIAL MENINGIOMA - A CASE-REPORT AND REVIEW OF THE LITERATURE

The simultaneous occurrence of a pituitary adenoma and an intracranial meningioma is a rare event. We report the coexistence of an eosinophi lic pituitary adenoma and a endotheliomatous meningioma, in the sellar region, and evaluate their endocrine, neuro-radiological and immunohi stochemical pattern. A 47-year-old woman affected by acromegaly was re ferred to us. Serum GH level was 82 ng/ml and remained unresponsive to both OGTT (75 g per os) and iv. GHRH 1-29 (100 ug); IGF-1 was 807 ng/ ml. Eight hours after acute sc administration of octreotide (100 ug) G H returned to normal levels (2.3 ng/ml). CT scan showed a large intra- and suprasellar mass involving the right cavernous sinus, with a retr osellar extension along the tentorium. A slight and inhomogeneous enha ncement, with a periferal rim of bright signal was apparent at MRI. Co nversely, the retrosellar component showed a bright homogeneous enhanc ement. The patient, therefore, underwent neurosurgery. Histological ex amination revealed the coexistence of 2 types of tissue: areas of endo theliomatous meningioma were interspersed among sheets of acidophilic adenoma tissue. Immunohistochemical analysis was performed in order to determine the relationship between the two masses: a positive stainin g for GH was shown in the areas of adenoma, as against for GHRH, neith er in the adenomatous tissue nor in the slices of meningioma. Although MRI showed a latero-sellar post-surgical residual of meningioma, seru m GH value was <1 ng/ml. In conclusion, the relationship beetwen the G H-secreting adenoma and the meningioma is unclear; however the GH-hype rsecretion is not induced by a hypothetic GHRH-activity from the menin gioma.