Growth, puberty and hypothalamic-pituitary function in children with suprasellar arachnoid cyst.

UNLABELLED

A suprasellar arachnoid cyst may cause disorders of growth, puberty and hypothalamic-pituitary function, due to the proximity of the cyst to the hypothalamic-pituitary area. A total of 30 patients (17 boys) with cyst diagnosed at 4.3 +/- 1 years were routinely evaluated at 5.4 +/- 1 years; 24 of them had one or multiple cyst derivations. Some 23 cases had an abnormal height, weight or puberty: short (< -2SD, 5 cases) or tall ( > 2SD, 10 cases) stature, overweight (body mass index, BMI, > 2SD, 6 cases), central precocious puberty (10 cases) and/or no progression of pubertal development (3 cases). The growth hormone (GH) peaks after pharmacological stimulation test were low (< 10 MICROg/L) in 16 patients, confirmed by a second evaluation in 8/11 of them. The plasma free thyroxine was low in five patients, prolactin was high in two and the cortisol and concomitant plasma and urinary osmolalities were normal. BMI was correlated negatively with the GH peaks (r = -0.37, P < 0.01) and positively with the plasma leptin concentrations (r = 0.55, P < 0.01). The plasma fasting insulin concentrations were also correlated negatively with the GH peaks (r = -0.55, P < 0.02) and positively with the plasma insulin-like growth factor I concentrations (r = 0.64, P < 0.002). The adult height (12 cases) was at 4SD in 1 and < -2SD in 4 patients, two of whom had precocious puberty untreated with gonadotropin releasing hormone (GnRH) analogue, and two had untreated GH deficiency. The adult height of those treated was normal. One girl had primary amenorrhoea and two boys had low plasma testosterone, despite a normal gonadotropin response to a GnRH test.

CONCLUSION

Suprasellar arachnoid cysts may cause deficiencies of growth hormone and thyrotropin, stimulation of the hypothalamic-pituitary-gonadal axis, tall stature and/or overweight. These last two disorders may be due to hyperinsulinism, itself due to suprasellar arachnoid cyst.