Endocrine Abstracts

Introduction: Immunocytochemistry methods have demonstrated that most of the ‘clinically non functional’ adenomas are actually gonadotrophin secreting adenomas or gonadotroph adenomas. Gonadotroph adenomas are discovered in patients presenting with visual field disorder. Pituitary imaging almost always demonastrates macroadenoma. Anterior pituitary insufficiency is much more frequent than gonad hyperstimulation. Herein, we present six cases of FSH and/or LH positive pituitary adenomas.

Cases: Six patients (three F, and three M) were diagnosed with pituitary adenoma. Two of our female patients were diagnosed with the complaint of oligomenorrhea because of high prolactin level. The other four patients had visual problems. All of our patients had macroadenoma on pituitary imaging. There were no any clinical picture of gonadal hyperstimulation. Histochemistry studies have shown that FSH was stained positively in three patients, FSH and LH both were stained in two patients. One patient was found to be only LH positive on histochemical staining. All patients had hypopituitarism. The levels of FSH and LH were not high according to reference range.

Conclusion: Although a significant percentage of non-functioning pituitary adenomas stain positively for LH and FSH, increased levels of circulating FSH and LH are very rare and account for only 10–15% of gonadotrophic adenomas. In our case series, there were no increased level of FSH and LH. FSH and/or LH positivity on histochemistry staining could be related to the issue of invasiveness. The possible mechanisms should be searched to explain the fact that most gonadotroph adenomas do not cause hormone excess but cause hormone deficiency.