tailieunhanh - Handbook of Diagnostic Endocrinology - part 3

Một vài trường hợp testosterone gia tăng liên kết với một adenoma LH-tiết đã được báo cáo, có một số trường hợp hyperstimulation buồng trứng, kết hợp với một adenoma tiết FSH. Xác định một adenoma gonadotropin tiết trước khi điều trị là hữu ích để đánh giá thành công của điều trị | 62 Vance nadism probably because of abnormal pulsatile gonadotropin secretion with failure to stimulate ovarian and testicular function. A few cases of increased testosterone associated with an LH-secreting adenoma have been reported as have several cases of ovarian hyperstimulation associated with an FSH-secreting adenoma. Identifying a gonadotropin-secreting adenoma prior to treatment is useful to assess success of treatment most commonly surgery by having a serum tumor marker to follow. The diagnosis of a gonadotroph adenoma is dependent on the presence of an excessive serum concentration of the particular hormone LH FSH a-subunit . Administration of gonadotropin-releasing hormone GnRH with measurement of LH FSH and a-subunit responses has been proposed as a method of diagnosis. However this has not proven to be of clinical utility. In general a nonsecretory pituitary macroadenoma is associated with normal or suppressed levels of LH FSH and a-subunit. These tumors are found in men with secondary hypogonadism and in postmenopausal women. Thus a slightly increased LH FSH or a-subunit may indicate a secretory gonadotropin tumor. The importance of identifying a gonadotrope adenoma is the use of a serum tumor marker to assess the effect of therapy. Initial therapy is surgical removal with postoperative serum measurement of the hormone produced in excess as well as an MRI study to assess anatomy optimally 3 mo after surgery . At the postoperative evaluation usually 6 wk after surgery gonadotropin and a-subunit concentrations should be measured to determine the response to surgery. Serial hormone measurement of the elevated hormone or hormones every 6-12 mo allows for detection of tumor recurrence and for early intervention. There are no consistently effective medical therapies for this type of tumor 24 thus emphasizing the need for lifelong follow up for recurrence including hormone measurements and at least a yearly imaging study MRI . Tumor recurrence may be treated