An 18-Month-Old Boy with Decreasing Height Velocity

Abstract

A n 18-month-old boy presented to our clinic for a routine well visit. His mother was concerned that, although he was cruising at age 12 months, he was still not walking or talking.He was born at 39 weeks and 5 days via cesarean delivery secondary to breech presentation. His APGAR (Appearance, Pulse, Grimace, Activity, Respiration) scores were 9 and 9 at 1 and 5 minutes, respectively. Antenatal course was only pertinent for gestational hypertension. His birth weight, length, and head circumference were 3,770 g (65th percentile), 52.7 cm (76th percentile), and 36.3 cm (49th percentile), respectively. His hospital course was uneventful and his newborn metabolic screen was normal.His immunizations were up to date and his medical history and family history were noncontributory. His diet was appropriate for age.A review of his growth parameters revealed a decline in linear growth velocity starting after age 6 months (from 76th percentile to <1st percentile) (Figure 1), a cessation of head growth starting at age 9 months (from 36th percentile to 2nd percentile), and a slight decline in weight percentile beginning at age 12 months (from 95th percentile to 73rd percentile).His vital signs were within normal limits with the exception of blood pressure of 130/90 mm Hg.On physical examination, he was noted to be happy, interactive, and in no acute distress. His skin was slightly dry and he had blonde lanugo hair throughout. HEENT (Head, Eyes, Ears, Nose, Throat) examination was only pertinent for chubby cheeks (Figure 2). His abdomen was soft, nontender, nondistended without organomegaly or masses, and with normal bowel sounds. Genitourinary examination revealed a Tanner 1 circumcised boy with bilaterally descended testes. The remainder of the examination was unremarkable.Due to his decline in length and head velocity, the patient was referred to endocrinology. Initial laboratory results from endocrinology showed a normal thyroid panel, renin activity, aldosterone, 24-hour vanillyl mandelic acid, metanephrines, dehydroepiandrosterone, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3; a decreased adrenocorticotropic hormone (ACTH) of 7 pg/mL; and increased serum cortisol (21.1 mcg/dL) and 24-hour urinary cortisol (65 mcg/24 h).Given the above results, a 12-hour overnight dexamethasone suppression test (DST) was completed and resulted in a serum cortisol of 25.6 mcg/mL (which is elevated). Subsequently, an adrenal ultrasound revealed a left adrenal mass, which was confirmed by magnetic resonance imaging (MRI) of the abdomen to be a solid left adrenal mass measuring 3.9 cm x 5.2 cm, suggestive of left adrenal adenoma. MRI of the brain was normal. After a normal metaiodobenzylguanidine scan, a left adrenalectomy was performed and a tumor weighing 54.4 g was resected.