The 15-Year-Old Who Is Not Growing and Is Being Teased
A 15-year-old boy is brought by his mother because he is "the shortest kid in his class." He is 152 cm (well below the 3rd percentile) and 45 kg. His mother reports he has grown only 2 cm in the past year. He is a picky eater, drinks little milk, and has no chronic illness. He is a straight-A student, plays trumpet, and says he is "fine" but his mother notes he has stopped attending swim practice and eats lunch alone. On exam: no goiter, normal male genitalia with Tanner stage 2 pubic hair and testicular volume 6 mL, no dysmorphic features. His father reached his adult height at 17 and was "a late bloomer"; his mother is 160 cm and father 172 cm. His mid-parental height is approximately 172 cm.
1. How do you distinguish constitutional delay of growth and puberty from pathologic short stature, and what does his exam tell you?
Read the worked answer
Constitutional delay is suggested by a family history of late puberty and late growth (his father), a bone age delayed by roughly the same amount as his height age, and a normal growth velocity for bone age. Pathologic causes to exclude: growth hormone deficiency, hypothyroidism, celiac disease, inflammatory bowel disease, chronic renal disease, and - given his Tanner 2 at 15 - delayed puberty from any of these or from hypogonadism.
His exam is informative but not reassuring on its own: Tanner 2 with 6 mL testes at 15 is delayed (testicular volume ≥4 mL generally marks pubertal onset, but 15 with only early changes is late). Mid-parental height of ~172 cm means his genetic potential is normal, so his current height is far below target - that gap argues for investigation rather than watchful waiting. Growth velocity of 2 cm/year is abnormally slow regardless of cause; normal prepubertal velocity is ~5 cm/year. Slow velocity plus delayed puberty is a red flag for an endocrine or systemic cause.
2. What initial workup do you order, and how do you address the psychosocial findings?
Read the worked answer
Order a bone age radiograph (left hand/wrist), CBC, CMP including creatinine, TSH and free T4, celiac serology (tTG-IgA with total IgA), and IGF-1. Consider a karyotype only if exam suggests otherwise; not indicated here. If bone age is markedly delayed and IGF-1 low, refer to pediatric endocrinology for GH stimulation testing. If bone age is delayed concordantly with height age and labs are normal, constitutional delay is likely and observation with serial heights every 3–6 months is reasonable - but he must be followed, not dismissed.
The psychosocial findings matter as much as the numbers. He has withdrawn from swimming, eats alone, and minimizes concerns while his mother reports the change. Screen for depression and bullying directly, alone with him. Short stature in boys is associated with being teased and with reduced self-esteem; the fix is not a height injection but addressing the social injury. Ask what happens at school, whether he has told anyone, and whether he wants help talking to his school. Validate that being the shortest kid is genuinely hard, and set a follow-up specifically for mood and peer relationships, not just growth.