Anterior Pituitary Function in Patients with Nonfunctioning Pituitary Adenoma: Results of Longitudinal Follow-up.

Abstract

Abstract.Studies of anterior pituitary function in patients treated for nonfunctioning pituitary adenomas have been limited by their short duration. The purpose of the present study was to examine pituitary function longitudinally among three types of patients: those with complete tumor removal (group A); those with subtotal or partial adenomectomy (group B); and those in group B who underwent additional radiation therapy (group C). The subjects were 33 patients whose anterior pituitary function was evaluated by provocative tests such as insulin induced hypoglycemia, thyrotropin releasing hormone administration test and luteinizing hormone releasing hormone administration test. They underwent preoperative evaluation and postoperative reevaluations at 2 weeks, 3 months, 6 months and annually thereafter, for over 10 years. Anterior pituitary function was restored within a year after surgery, if at all. No additional function was restored after one year from treatment. In group A, no one developed impairment of anterior pituitary function after one year from surgery. In group B, however, new impairment was noted at intervals, due to tumor regrowth. In Group C, deficiencies developed after one year, irrespective of tumor regrowth. In conclusion, lifelong endocrinological follow-up is recommended for patients receiving postoperative irradiation, and for patients with potential for tumor regrowth.On the other hand, patients with total adenomectomy may be exempted from periodic endocrinological follow-up if they do not need postoperative hormonal replacement therapy.

Hypothalamic-Pituitary Axis in Non-Functioning Pituitary Adenomas: Focus on the Prevalence of Isolated Central Hypoadrenalism

“…We also observed that the prevalence of the different pituitary deficiencies was different in macro- and microadenomas: while the most frequent deficit in macroadenomas was hypogonadism, hypoadrenalism was most frequently observed in microadenomas, although the limited number of patients evaluated for GHD by dynamic tests in the present series might indeed underestimate the prevalence of this defect. Nevertheless, the strength of our study is the highest number of microadenomas described to date (table 3), while most of the other series had the bias of including only macroadenomas [5,6,7,8,31,32]. …”

“…Accordingly, secretion of growth hormone (GH) fails first, followed by luteinizing hormone (LH)/follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH) and finally by adrenocorticotropic hormone (ACTH) [3,4]. Many subsequent studies reported conflicting data but, despite that, this dogma is still generally accepted [5,6,7,8,9]. Data from the literature are very heterogeneous, both for case selection and for diagnostic criteria, with most of the series including almost exclusively macroadenomas.…”

Nonfunctioning Pituitary Tumors and Pituitary Incidentalomas

“…Reports from nine series of patients showed that the recurrence rates for tumors after surgery were 10.3% of 224 patients who received routine postoperative radiotherapy and 25.5% of 428 patients who did not receive such routine radiotherapy (Table 6) [70][71][72][93][94][95][96][97][98]. More recent series have reported similar data stratified by the presence or absence of tumor on the initial postoperative MRI scan [73,75,78,[99][100][101][102][103]. For those patients who had no visible tumor on postoperative MRI, none of 11 who received routine radiotherapy had recurrences and only 13.1% of 359 patients who did not receive routine radiotherapy experienced recurrences (see Table 6).…”

“…Clearly, the most common symptoms and signs are visual field disturbance, headache, and hypopituitarism, although the last was often only found with detailed testing. Testing of pituitary function in nine series [69][70][71][72][73][74][75][76][77][78][79][80] showed that the loss of hormones was on the order of loss of GH greater than loss of luteinizing hormone (LH)/follicle-stimulating hormone (FSH), greater than loss of ACTH, greater than loss of TSH (Table 4). In many older series, testing for GH deficiency in adults was not performed because it was believed that the finding of GH deficiency would not change therapy.…”

Changes in the epithelium of Rathke cleft cyst associated with inflammation

“…Anterior pituitary function was tested by checking insulin tolerance and by administering both TSH-releasing hormone (500 g) to measure levels of TSH and prolactin, and LH-releasing hormone (100 g) to measure levels of LH and FSH. Concentrations of serum GH, cortisol, TSH, prolactin, LH, and FSH were determined using a radioimmunoassay, which was described in an earlier study 18 in which the normal basal values and normal responses to stimuli used in this study were also described.…”