# Clinical Cases: Growth and Development

## Case 1: Constitutional Growth Delay

### Patient Demographics
- **Age:** 14-year-old male
- **Sex:** Male

### Chief Complaint
"My son is the shortest boy in his class and hasn't started puberty yet."

### History of Present Illness
A 14-year-old male presents with his mother who is concerned about his short stature and lack of pubertal development. He has always been shorter than his peers, consistently tracking at the 5th percentile for height. His mother reports he was a "late bloomer" similar to his father, who reportedly did not reach his full height until age 18. The patient denies any chronic illness symptoms, headaches, visual changes, or fatigue. He eats well and is active in sports despite being smaller than teammates.

### Growth Parameters
- **Height:** 147 cm (5th percentile, -1.9 SD)
- **Weight:** 38 kg (10th percentile)
- **BMI:** 17.6 kg/m2 (25th percentile)
- **Growth velocity:** 4.5 cm/year (below expected pubertal velocity)

### Physical Examination
- **General:** Well-appearing, prepubertal male
- **HEENT:** Normal, no visual field defects
- **Thyroid:** Normal size, no nodules
- **Cardiovascular:** Regular rate and rhythm, no murmurs
- **Abdomen:** Soft, non-tender, no organomegaly
- **Genitourinary:** Tanner stage I pubic hair, Tanner stage I genitalia, testicular volume 3 mL bilaterally (prepubertal)
- **Extremities:** No skeletal abnormalities
- **Neurologic:** Normal

### Workup
- **Bone age (left hand/wrist X-ray):** 11.5 years (delayed 2.5 years relative to chronologic age)
- **CBC:** Normal
- **CMP:** Normal
- **TSH:** 2.1 mIU/L (normal)
- **Free T4:** 1.2 ng/dL (normal)
- **IGF-1:** 185 ng/mL (normal for bone age)
- **LH/FSH:** Prepubertal levels
- **Testosterone:** 15 ng/dL (prepubertal)

### Diagnosis
**Constitutional delay of growth and puberty (CDGP)**

### Clinical Reasoning
The combination of short stature with delayed bone age, prepubertal status at age 14, family history of late puberty in father, otherwise normal health, and normal laboratory values supports the diagnosis of constitutional delay. The bone age delay indicates significant remaining growth potential. This is a normal variant of growth and puberty rather than a pathologic condition.

### Management
1. **Reassurance:** Explain the benign nature of the condition and expected eventual catch-up growth and pubertal development
2. **Growth prediction:** Based on bone age, predicted adult height is within normal range (mid-parental target height)
3. **Observation:** Serial monitoring every 6 months to document growth velocity and pubertal progression
4. **Optional treatment:** Low-dose testosterone therapy (50-100 mg IM monthly for 4-6 months) can be offered if psychological distress is significant, to initiate puberty
5. **Psychological support:** Address any bullying or self-esteem concerns

### Clinical Image
![Bone age X-ray showing delayed skeletal maturation](case_01_image.jpg)

**Image Description:** Bone age radiograph of the left hand and wrist used to assess skeletal maturation in children with growth concerns.

**Source:** Radiopaedia - Bone age assessment
**URL:** https://radiopaedia.org/cases/bone-age-normal-13
**License:** CC BY-NC-SA 3.0

---

## Case 2: Precocious Puberty

### Patient Demographics
- **Age:** 6-year-old female
- **Sex:** Female

### Chief Complaint
"My daughter is developing breasts and I'm worried it's too early."

### History of Present Illness
A 6-year-old girl is brought in by her mother who noticed breast development starting approximately 6 months ago with progressive enlargement. The mother also reports she has grown 3 inches in the past year, which is faster than her older siblings grew at this age. There is no history of headaches, visual changes, seizures, or behavioral changes. The child has no exposure to hormonal creams, supplements, or medications. No pubic or axillary hair has been noted. There is no vaginal bleeding.

### Growth Parameters
- **Height:** 125 cm (97th percentile, +2.1 SD)
- **Weight:** 26 kg (90th percentile)
- **BMI:** 16.6 kg/m2 (75th percentile)
- **Growth velocity:** 9 cm/year (accelerated)

### Physical Examination
- **General:** Well-appearing girl, appears older than stated age
- **HEENT:** Normal, visual fields intact
- **Thyroid:** Normal
- **Cardiovascular:** Normal
- **Abdomen:** Soft, non-tender
- **Breast:** Tanner stage III bilateral breast development (elevated breast contour, no areolar separation)
- **Genitourinary:** Tanner stage I pubic hair, normal external genitalia, no clitoromegaly, estrogenized vaginal mucosa
- **Skin:** No cafe-au-lait spots
- **Neurologic:** Normal

### Workup
- **Bone age:** 8.5 years (advanced 2.5 years)
- **LH (basal):** 1.8 mIU/mL (pubertal range)
- **FSH:** 4.2 mIU/mL
- **Estradiol:** 28 pg/mL (elevated)
- **GnRH stimulation test:** LH rises to 12 mIU/mL (pubertal response)
- **TSH:** Normal
- **Pelvic ultrasound:** Enlarged uterus (4.2 cm length) with endometrial stripe, bilateral enlarged ovaries with multiple follicles
- **Brain MRI:** Normal, no hypothalamic-pituitary lesions

### Diagnosis
**Central (gonadotropin-dependent) precocious puberty, idiopathic**

### Clinical Reasoning
Breast development before age 8 in girls defines precocious puberty. The pubertal LH response to GnRH stimulation confirms central activation of the hypothalamic-pituitary-gonadal axis. The advanced bone age and accelerated growth velocity indicate significant estrogen exposure. Normal brain MRI excludes hypothalamic hamartoma or other CNS lesions, supporting idiopathic central precocious puberty, which is most common in girls.

### Management
1. **GnRH agonist therapy:** Leuprolide depot 7.5 mg IM monthly or 11.25 mg every 3 months to suppress the HPG axis
2. **Treatment goals:** Slow pubertal progression, normalize growth velocity, preserve adult height potential, address psychosocial concerns
3. **Monitoring:** Follow height velocity, Tanner staging, bone age, and LH/FSH levels every 6 months
4. **Psychological support:** Age-appropriate counseling about body changes
5. **Treatment duration:** Continue until average age of puberty (typically age 10-11), then discontinue to allow normal pubertal progression

### Clinical Image
![Tanner stages of breast development](case_02_image.jpg)

**Image Description:** Tanner staging diagram showing the five stages of female breast development used to assess pubertal progression.

**Source:** Wikimedia Commons
**URL:** https://commons.wikimedia.org/wiki/File:Tanner_stages_female.svg
**License:** CC BY-SA 4.0

---

## Case 3: Growth Hormone Deficiency

### Patient Demographics
- **Age:** 8-year-old male
- **Sex:** Male

### Chief Complaint
"Our son has been falling off his growth curve for the past two years."

### History of Present Illness
An 8-year-old boy presents with his parents who report progressive decline in his growth percentiles over the past 2 years. He was previously tracking at the 50th percentile for height but has now fallen to below the 3rd percentile. Parents report he seems to have more body fat around his abdomen despite not overeating. He was born via breech delivery with mild birth asphyxia but had normal development otherwise. He has had no recent illnesses, takes no medications, and has a good appetite. He fatigues more easily than his peers during physical activity.

### Growth Parameters
- **Height:** 112 cm (<3rd percentile, -2.8 SD)
- **Weight:** 24 kg (25th percentile)
- **BMI:** 19.1 kg/m2 (85th percentile - relatively overweight for height)
- **Growth velocity:** 3.2 cm/year (severely diminished; normal is 5-6 cm/year prepubertally)
- **Previous height at age 6:** 108 cm (50th percentile)

### Physical Examination
- **General:** Short stature, appears younger than stated age, slightly overweight
- **HEENT:** Frontal bossing, midface hypoplasia, depressed nasal bridge
- **Eyes:** Normal visual fields
- **Cardiovascular:** Normal
- **Abdomen:** Truncal adiposity, no organomegaly
- **Genitourinary:** Small phallus for age, prepubertal testes
- **Extremities:** Short limbs proportionate to trunk, small hands and feet
- **Skin:** Fine, thin skin
- **Neurologic:** Normal

### Workup
- **Bone age:** 5 years (delayed 3 years)
- **IGF-1:** 45 ng/mL (low for age)
- **IGFBP-3:** 1.2 mg/L (low)
- **GH stimulation test (arginine-insulin):** Peak GH 3.2 ng/mL (deficient; normal >10 ng/mL)
- **TSH:** 2.8 mIU/L (normal)
- **Free T4:** 1.0 ng/dL (normal)
- **Morning cortisol:** 12 mcg/dL (normal)
- **CBC, CMP:** Normal
- **Brain MRI:** Small anterior pituitary, ectopic posterior pituitary bright spot, absent pituitary stalk

### Diagnosis
**Growth hormone deficiency secondary to pituitary stalk interruption syndrome**

### Clinical Reasoning
The declining growth velocity, falling percentiles, markedly delayed bone age, low IGF-1/IGFBP-3, and failed GH stimulation test confirm growth hormone deficiency. The characteristic MRI findings of pituitary stalk interruption syndrome explain the etiology, likely related to perinatal insult from breech delivery. The truncal adiposity and micropenis are consistent with GH deficiency. Evaluation for additional pituitary hormone deficiencies is warranted.

### Management
1. **Growth hormone replacement:** Recombinant human GH 0.024-0.034 mg/kg/day subcutaneously at bedtime
2. **Monitoring:** Height velocity (target >8 cm/year in first year), IGF-1 levels every 6 months, bone age annually
3. **Screen for additional pituitary deficiencies:** ACTH stimulation test, thyroid function monitoring, prolactin
4. **Long-term follow-up:** Monitor for development of additional hormone deficiencies, especially at puberty
5. **Treatment duration:** Continue until growth plates fuse or height velocity <2 cm/year with bone age >14 years

### Clinical Image
![MRI showing pituitary stalk interruption](case_03_image.jpg)

**Image Description:** Sagittal MRI of the brain demonstrating pituitary stalk interruption syndrome with absent pituitary stalk and ectopic posterior pituitary.

**Source:** Radiopaedia
**URL:** https://radiopaedia.org/cases/pituitary-stalk-interruption-syndrome-1
**License:** CC BY-NC-SA 3.0