下垂体生殖細胞腫における成長ホルモンを介さない成長：臨床的特徴と予測因子

Sellar germ cell tumors (GCTs) commonly cause growth hormone deficiency (GHD) and impaired growth in children. A subset of patients maintains near-normal growth despite GHD, a phenomenon termed growth without growth hormone (GWGH), with unclear mechanisms. This study aimed to characterize the clinical features and predictors of GWGH in pediatric sellar GCTs.

Patients with sellar GCTs and GHD presenting to our hospital between July 2021 and December 2024, with hypogonadotropic hypogonadism or prepubertal status, were included. Patients with annual growth ≥5 cm were classified as GWGH, and a 1:2 age- and sex-matched non-GWGH group served as controls. Clinical characteristics, pituitary dysfunction, hormone replacement therapy, hypothalamic syndrome manifestations, and fasting insulin levels were compared. Logistic regression identified independent predictors of GWGH.

Among 130 patients, 15 (11.5%) exhibited GWGH. GWGH patients had more obesity, larger tumors, and greater hypothalamic involvement, and more hypothalamic syndrome components. Pituitary dysfunction and hormone replacement therapy did not differ significantly between groups. Fasting insulin was significantly higher in the GWGH group than in controls (22.58 ± 8.76 vs 7.41 ± 4.38 μIU/mL, p < 0.001). Multivariate logistic regression identified fasting insulin as an independent predictor of GWGH (OR = 1.61, 95% CI 1.14-2.25, p = 0.006).

GWGH occurs in 11.5% of children with sellar GCTs and GHD, and is associated with hypothalamic involvement, obesity, and hyperinsulinemia. Elevated fasting insulin may partly explain GWGH, but prospective studies are needed to clarify the underlying mechanisms.