Recurrent Rathke's Cleft Cysts: Incidence and Surgical Management in a Tertiary Pituitary Center over 2 Decades.

BACKGROUND: Limited data exist pertaining to outcomes following surgery for recurrent Rathke's cleft cysts (RCC). OBJECTIVE: To determine treatment outcomes in patients undergoing reoperation for recurrent or residual RCCs. METHODS: A retrospective analysis of 112 consecutive RCC operations in 109 patients between 1995 and 2017 was conducted. RESULTS: Eighteen patients underwent 21 RCC reoperations with a mean follow-up of 58 mo. Patient symptoms prior to reoperation included headaches (14, 66.7%) and vision loss (12, 57.1%). Thirteen of 18 patients (72.2%) required hormone supplementation prior to reoperation including 5 with diabetes insipidus (DI). Mean RCC diameter was 16 mm and 76% had suprasellar extension. Compared to index RCC cases, intraoperative cerebrospinal fluid leak repair was more common in reoperation cases (15/21, 71% vs 43/91, 47%, P = .05). There was 1 carotid artery injury without neurological sequelae, and 2 postoperative cerebrospinal fluid (CSF) leaks (9.5%). Rates of transient hyponatremia (3/10, 30% vs 4/91, 4.4%, P = .04) and transient DI (5/10, 50% vs 17/91, 18.7%, P = .04) were higher in the reoperation vs index group. Improved headaches and vision were reported in 4/12 (33%) and 8/12 (61.5%) of RCC reoperation patients, respectively. Two patients developed new permanent DI. A higher proportion of reoperation patients had RCC squamous metaplasia (24% vs 5.4%, P = .02) or wall inflammation (42.9% vs 2.2%, P < .001) on pathological examination. CONCLUSION: Reoperation for RCCs is generally safe at tertiary pituitary centers and often results in improved vision. Hypopituitarism is less likely to improve following reoperation for recurrent RCCs. Several histopathological features may help characterize "atypical RCCs" with a higher likelihood of recurrence/progression.

Selective use of the insulin tolerance test to diagnose hypopituitarism.

The insulin tolerance test is considered the gold standard for assessing the hypothalamic-pituitary-adrenal and growth hormone (GH) axes, but its use varies considerably among different endocrine units. We recommend using the insulin tolerance test to assess the hypothalamic-pituitary-adrenal axis within 3 months of pituitary surgery, where adrenocorticotropic hormone 1-24 testing is equivocal, and to assess for GH deficiency where the patient is being considered for GH replacement therapy. We also discuss safety issues, how to ensure adequate hypoglycaemia and possible alternative tests, such as the overnight metyrapone test and glucagon test.

The pre-operative endocrine assessment of craniopharyngiomas.

Pre-operative endocrinopathies are common in patients presenting with craniopharyngiomas. Clinical features may not be obvious and careful pre-operative endocrine assessment is essential. Failure to recognise and address pre-operative diabetes insipidus and secondary hypoadrenalism is potentially fatal. We review the available published data on pre-operative endocrine dysfunction and suggest an approach to assessment and management before surgery.

An assessment of bone mineral density in patients with Addison's disease and isolated ACTH deficiency treated with glucocorticoid.

Glucocorticoid replacement therapy needs to be tailored to individual patient's requirements in order to avoid risk of over or under medication. We measured bone mineral density (BMD) of lumbar spine using dual X-ray absorptiometory in 10 patients with Addison's disease and 5 patients with isolated ACTH deficiency receiving glucocorticoid replacement therapy. We also examined the effect of glucocorticoid replacement on BMD. Decreased %BMD (less than 80% of age-matched controls) was found in 2 female patients who had received hydrocortisone at a dose of 14.8 and 15.4 mg/m(2)/day. In contrast, no patient receiving a hydrocortisone dose of less than 12.4 mg/m (2)/day had decreased %BMD. There was no correlation between %BMD and hydrocortisone dose (mg/m(2)), duration of therapy, or cumulative hydrocortisone dose when treated with appropriate dose of hydrocortisone (<13.6 mg/m(2)). There was also no statistically significant difference in %BMD with age. We concluded that long-term glucocorticoid replacement therapy does not induce bone loss in patients with glucocorticoid deficiency unless an excessive dose of hydrocortisone is given.

Reproducibility of the insulin tolerance test (ITT) for assessment of growth hormone and cortisol secretion in normal and hypopituitary adult men.

OBJECTIVE: The within subject variability of the insulin tolerance test (ITT) for assessment of growth hormone (GH) status and cortisol reserve has rarely been examined, particularly in patients with hypopituitarism. This becomes important when biochemical criteria are used to determine which adults with hypopituitarism should receive GH and/or cortisol replacement. In the present study we assessed the reproducibility of GH and cortisol responses in repeated ITTs. Baseline insulin-like growth factor 1 (IGF-1) levels were also assessed for reproducibility on each occasion. DESIGN AND PATIENTS: Three consecutive ITTs were performed in seven normal adult men (ages 22-27 years) and two ITTs in 11 men with hypopituitarism and suspected GH deficiency (ages 23-48 years). MEASUREMENTS: Serum GH and IGF-1 were measured by immunoradiometric and cortisol by immunofluorimetric assays. RESULTS: In normal men group peak GH responses did not differ between the three tests. There was no correlation between individual peak values. The within subject peak GH variability was between 4.6 and 59.3%, and the overall variability in 21 tests was 35%. The lowest peak GH concentration was 70 mU/l (27 microg/l). All hypopituitary men had severe GH deficiency (all peak GH concentrations < 4 mU/l (1.5 microg/l) in both tests). There was a highly significant correlation between individual peak GH values (r = 0.95, P < 0.0001). Basal IGF-1-values in normal and hypopituitary men were highly correlated between tests (r = 0.98, P < 0.0001). The overall within subject variability of IGF-1-values was 11.9% in normal and 22.7% in hypopituitary men. In normal men group peak cortisol responses were not different between the three tests. There was a good correlation between individual peak cortisol responses in the three ITTs. The within subject peak cortisol variability (median 8.3%; range 0.7-21.5%) was significantly less than that of GH (P < 0.03) in two of three test comparisons. In hypopituitary men the within subject peak cortisol variability (median 41.6%; range 3.5-92.7%) was significantly greater (P < 0.001) than in normal men. All patients were correctly classified as cortisol deficient or normal in both ITTs. CONCLUSION: The cortisol response to repeated hypoglycaemia is very reproducible in normal men but the GH response is less so. In hypopituitary men the reproducibility of the GH response is good while that of the cortisol response is poor. However, a single ITT did not misclassify hypopituitary patients who are severely GH and/or ACTH deficient and was therefore adequate for clinical decisions regarding GH and/or cortisol replacement. Nevertheless, it remains possible that a single ITT could misclassify some hypopituitary patients with partial GH or ACTH deficiency.

Assessment of corticosteroid replacement therapy in adults with adrenal insufficiency.

Recent work has taught us that our conventional approach to corticosteroid replacement therapy requires review. Specifically, the doses of hydrocortisone we have used are probably too high for the majority, and should ideally be administered in three or more doses through the day. Nevertheless, there is not much hard evidence that excessive glucocorticoid replacement per se will lead to adverse effects such as osteoporosis, even though it may exacerbate any tendency in those who are predisposed to it for other reasons. As such, there is no compelling need for using determinations of either UFC excretion or of the serum cortisol profile in the routine management of patients on replacement therapy. Nevertheless, such measures may be considered in those thought to be at particular risk of osteoporosis, and in whom it is felt that special effort should be made to ensure that they are receiving the minimum dose possible. In such circumstances, a cortisol day curve is likely to be of more value than measurement of UFC.

Standard and low-dose short adrenocorticotropin test compared with insulin-induced hypoglycemia for assessment of the hypothalamic-pituitary-adrenal axis in children with idiopathic multiple pituitary hormone deficiencies.

Insulin-induced hypoglycemia (IIH) is the gold standard test for assessment of the integrity of the hypothalamic-pituitary-adrenal (HPA) axis, but it may be hazardous. We sought to determine whether the standard (250 micrograms) or low-dose (1 microgram/1.73 m2) short ACTH test can replace IIH in patients with idiopathic multiple pituitary hormone deficiencies (MPHD). Three groups of subjects were studied: 1) control group, children with early or accelerated puberty and no other evidence of adrenal or pituitary pathology (n = 13, age 10.1 +/- 2.2 yr, 3 males); 2) patients with idiopathic hypothalamic pituitary insufficiency and either isolated GH deficiency or MPHD and preserved HPA function (n = 20, age 13.7 +/- 4.4 yr, 13 males); and 3) MPHD patients with impaired HPA axis function (n = 10, age 16.8 +/- 4.8 yr, 9 males). IIH and the 250 micrograms and 1 microgram/1.73 m2 ACTH tests were performed in groups 2 and 3; group 1 underwent only the ACTH tests. Pass peak cortisol level was defined as 520 nmol/L. No significant difference was noted between the standard and low-dose tests in the 30-min cortisol response to ACTH. Basal and peak cortisol levels attained on both ACTH tests were similar in groups 1 and 2 and significantly lower in group 3 (P < 0.0001). Both the 250 and 1 microgram ACTH tests were highly correlated with IIH (r = 0.71, P < 0.0001 for the 250 micrograms, r = 0.7, P < 0.0001 for the 1 microgram, n = 30), and both demonstrated high sensitivity (90% each) and specificity (100% and 90%, respectively) compared with IIH. We conclude that in idiopathic MPHD patients, both the standard and low-dose ACTH tests are equivalent to IIH in detecting HPA insufficiency. We suggest that they can replace IIH as a screening test for the integrity of the HPA axis in children with suspected MPHD.

The assessment of the functional capacity of the hypothalamic-pituitary-adrenal axis by measurement of basal plasma and urinary cortisol in comparison with insulin-induced hypoglycaemia and metyrapone tests.

In 58 patients with a pituitary adenoma or hypothalamic-pituitary disease an insulin-induced hypoglycaemia test and a metyrapone test were performed. The results of these tests were compared with morning plasma cortisol levels and daily urinary cortisol excretion as indicators of insufficiency of the pituitary-adrenal axis. Basal unstressed urinary cortisol excretion was insufficient in 20 cases. These patients, needing life-long glucocorticoid substitution therapy, were excellently detected by both tests and daily urinary cortisol excretion. The predictive value of the morning plasma cortisol level was inferior to these. Five cases with sufficient basal cortisol excretion showed a defective adrenal response to hypoglycaemia. These patients were not discriminated by the metyrapone test, urinary cortisol excretion or plasma cortisol levels. It is concluded that urinary cortisol excretion can safely replace the hypoglycaemia and metyrapone test for the detection of insufficient basal cortisol production in patients with hypothalamic and/or pituitary disorders.

Rapid assessment of corticotropin reserve after pituitary surgery.

Corticotropin deficiency may occur after pituitary surgery, and, if unrecognized and untreated, it can be fatal. In this study the insulin tolerance test was used to assess hypothalamic-pituitary-adrenal reserve five to seven days after pituitary surgery, and postoperative morning serum cortisol concentration was compared with the insulin tolerance test for predicting corticotropin deficiency. In 35 patients with pituitary tumors studied prospectively, 27 had normal insulin tolerance test results five to seven days after pituitary surgery; in these patients, the morning serum cortisol concentration two to three days after surgery was 250 nmol/L (9 micrograms/dL) or greater. Eight patients had subnormal insulin tolerance test results or clinical evidence of adrenal insufficiency; the morning serum cortisol concentration in these patients was 80 nmol/L (3 micrograms/dL) or less. Postoperative adrenal insufficiency was transient (one to three months) in five of these eight patients. We retrospectively identified 45 patients whose postoperative morning serum cortisol values were 200 nmol/L (7 micrograms/dL) or greater; none of these patients had clinical evidence of adrenal insufficiency. We conclude that a morning serum cortisol level obtained two to three days after surgery and 24 hours after the discontinuation of hydrocortisone accurately predicts postoperative corticotropin reserve.