Clinical characterization of Japanese children with Cushing's disease.

Cushing's disease (CD) is very rare in children. Nineteen children (≤18 years) with CD (median age at diagnosis: 13 [6-17] years; 12 females) were retrospectively analyzed using medical records (1994-2025) from Toranomon Hospital, Tokyo, Japan. Facial changes (88.9%), weight gain with decreased growth rate (88.9%), central obesity (88.9%) and hirsutism (94.4%) were frequently observed at diagnosis. Median time to diagnosis was 2.7 (0.25-5.8) years. Screening for endogenous hypercortisolism was assessed by 24-hour urinary free cortisol levels, serum cortisol levels at 23:00, and serum cortisol levels at 8:00 after a low-dose dexamethasone suppression test (DST), each with 100% sensitivity. Etiological diagnosis was evaluated by serum cortisol levels at 8:00 after a high-dose DST, plasma adrenocorticotropic hormone (ACTH) levels after a corticotropin-releasing hormone test, and plasma ACTH levels at 8:00, with sensitivities of 85.7%, 93.8%, and 83.3%, respectively. The actual tumor detection rate on magnetic resonance imaging (MRI) was 72.2%. Micro-pituitary neuroendocrine tumors were identified in 77.8% of patients. The total remission rate was 94.4% (median follow-up: 3.8 [0-10.4] years). The mean standard deviation scores (SDS) (SD) of height and body mass index (BMI) at onset and diagnosis were -0.45 (0.63) and -2.0 (1.1), and 0.61 (0.95) and 1.6 (0.75), respectively. Height and BMI SDS (SD) improved to -1.0 (0.80) and 0.091 (1.2) at the last visit (age: 11.4-17.5 years; follow-up: 1-8.6 years), respectively. This study revealed clinical characteristics of Japanese children with CD, including distinctive BMI SDS and a high tumor detection rate by MRI.