A 14-year-old girl is brought to the clinic for an annual well check. Her father says that the patient has always been a picky eater but does eat 3 meals a day. She used to stay up late talking to friends but lately has been tired and goes to bed after dinner. Blood pressure is 110/70 mm Hg, and pulse is 52/min. Breast examination is consistent with Tanner stage 1, and genital examination shows pubic hair consistent with Tanner stage 4. The remainder of the examination is unremarkable. The patient's growth chart is shown in the image below: Bone age is significantly less than chronologic age. Which of the following is the most likely cause of this patient's presentation?

Question

A 14-year-old girl is brought to the clinic for an annual well check.  Her father says that the patient has always been a picky eater but does eat 3 meals a day.  She used to stay up late talking to friends but lately has been tired and goes to bed after dinner.  Blood pressure is 110/70 mm Hg, and pulse is 52/min.  Breast examination is consistent with Tanner stage 1, and genital examination shows pubic hair consistent with Tanner stage 4.  The remainder of the examination is unremarkable.  The patient's growth chart is shown in the image below:  Bone age is significantly less than chronologic age.  Which of the following is the most likely cause of this patient's presentation?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d668_76ca_bc81_dbd6ee646368_MD0003_00 This patient has short stature, or height ≤2nd percentile, in addition to a declining linear growth velocity, or a height curve crossing ≥2 major percentiles (ie, 25th, 10th, 2nd). In contrast to benign variants of growth (eg, constitutional growth delay, familial short stature), which are characterized by a normal growth velocity with maintenance of height percentiles, this patient's findings are concerning for pathologic short stature (Choices B and C). The first step in the evaluation of short stature is a bone age determination, which assesses skeletal maturity through radiographic examination of the wrist. Delayed bone age with declining linear growth velocity can be caused by: poor diet (eg, chronic malnutrition) systemic disease (eg, celiac disease) endocrinopathy (eg, hypothyroidism) This patient also has fatigue, bradycardia, and delayed puberty, findings concerning for acquired hypothyroidism (eg, autoimmune thyroiditis). Because thyroid hormones are regulated by the hypothalamic-pituitary axis, thelarche (breast development stimulated by estradiol) is specifically affected, whereas adrenarche (eg, pubic hair development) is not affected because it is driven by adrenal hormones. Additional clinical manifestations of hypothyroidism include cold intolerance, constipation, and dry or brittle nails and hair. (Choice A) An adrenal tumor typically produces excess androgens and presents with virilization and advanced bone age. In contrast, this patient has delayed thelarche and a delayed bone age. (Choice E) Chronic, inadequate caloric intake can cause delayed puberty, bone age, and linear growth velocity. However, a significant decline in weight percentiles would be expected, and this patient's weight percentiles are relatively stable. Educational objective: Short stature (height ≤2nd percentile) with a declining linear growth velocity and delayed bone age is pathologic. Additional findings suggestive of hypothyroidism as the cause of short stature include bradycardia, fatigue, and delayed thelarche. References: Pediatric hypothyroidism: diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/28534114) Disorders of puberty: an approach to diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/29094880)

A 14-Year-Old Girl Is Brought to the Clinic for an Annual