What is the diagnosis and treatment for a female patient presenting with sudden weight gain, amenorrhea, moon-shaped face, buffalo hump, thin extremities, hair thinning, and stunted linear growth?

SOAP Note: Cushing's Syndrome

SUBJECTIVE

Chief Complaint: 30-pound weight gain over 3 months with amenorrhea

History of Present Illness:

• Weight gain: Rapid 30-pound increase over 3 months with central distribution 1
• Menstrual history: Amenorrhea (absent periods) 2, 3
• Hair changes: Thinning of scalp hair 3
• Growth: Stunted linear growth (critical finding in pediatric/adolescent patients) 1, 4

OBJECTIVE

Vital Signs: Document blood pressure (hypertension expected) 1, 5

Physical Examination Findings:

General Appearance:

• Central obesity with abnormal fat distribution 1, 5
• Moon-shaped face (facial plethora and rounded appearance) 1, 5

Head/Neck:

• Buffalo hump (dorsocervical fat pad) 1, 5
• Supraclavicular fat accumulation 5, 4

Extremities:

• Thin upper and lower extremities with proximal muscle weakness or wasting 1, 5

Skin:

• Examine for wide (>1 cm) purple/violaceous striae, particularly on abdomen 1, 5
• Assess for hirsutism (excessive hair growth in male-pattern distribution) 1, 5
• Check for facial plethora and acne 5

ASSESSMENT

Primary Diagnosis: Cushing's Syndrome

This patient presents with the classic tetrad of findings most specific for Cushing's syndrome: abnormal fat distribution in supraclavicular and temporal fossae, proximal muscle weakness, and stunted linear growth with continued weight gain. 5, 4

The combination of moon face, buffalo hump, central obesity with thin extremities, amenorrhea, and stunted growth creates an extremely high pretest probability for Cushing's syndrome 6. The prevalence is <0.1% in the general population, but this constellation of findings has high specificity 5.

Critical consideration: Stunted linear growth with continued weight gain is one of the most specific features for Cushing's syndrome, particularly in children and adolescents 1, 4, 7.

PLAN

Diagnostic Workup

First-Line Confirmatory Testing (perform at least one, preferably two):

1. Overnight 1-mg dexamethasone suppression test (preferred initial test) 1, 6

   • Administer 1 mg dexamethasone at 11 PM
   • Measure serum cortisol at 8 AM
   • Failure to suppress cortisol to <1.8 μg/dL confirms hypercortisolism 6
   • Sensitivity 95%, specificity 80% 6

2. 24-hour urinary free cortisol excretion (preferably multiple collections) 1, 7

3. Midnight salivary cortisol (appears to be the most useful screening test) 1, 7

Note: Random serum cortisol has no diagnostic value due to pulsatile secretion and wide normal variation 6.

Etiology Determination (after confirming hypercortisolism)

Measure morning plasma ACTH concentration: 6, 4, 8

• ACTH normal or elevated: Suggests ACTH-dependent Cushing's (pituitary Cushing's disease 70% or ectopic ACTH 15%) 4
• ACTH low or undetectable: Suggests ACTH-independent (adrenal source 15%) 6, 4

Imaging Studies

Based on ACTH results:

• If ACTH-dependent: MRI of pituitary gland 2
• If ACTH-independent: CT scan of abdomen with adrenal protocol 2

Treatment Planning

Definitive treatment is surgical resection of the tumor for all forms of Cushing's syndrome. 4

For pediatric/adolescent patients specifically:

• Surgery and/or radiotherapy are recommended to allow rapid normalization of growth and puberty 1
• Medical therapies should be confined to normalizing cortisol levels in preparation for surgery or while awaiting biochemical response to radiotherapy 1
• Reserve bilateral adrenalectomy only for severe refractory disease or life-threatening emergencies 1

Post-Treatment Monitoring (Critical for Growth)

After achieving remission:

• Perform dynamic testing for GH deficiency soon after definitive therapy (within 3 months) in patients who have not completed linear growth 1
• Initiate GH replacement promptly if GH deficiency is proven or if catch-up growth fails to occur 1
• Monitor pubertal progression closely to identify hypogonadotrophic hypogonadism 1
• Consider GnRH analogue therapy to delay puberty and epiphyseal closure, maximizing growth potential 1
• Assess bone mineral density prior to adult transition in high-risk patients 1

Common Pitfalls to Avoid

• Do not rely on random cortisol measurements - they have no diagnostic value 6
• Do not delay diagnosis - early recognition is critical, especially in growing children where stunted growth with continued weight gain is highly specific 1, 4, 7
• Do not use long-term medical therapy as primary treatment in children/adolescents - definitive surgical treatment is needed to normalize growth and puberty 1
• Do not forget to screen for GH deficiency post-treatment - there is a limited window to achieve normal adult height 1

Follow-up

• Urgent endocrinology referral for confirmatory testing and treatment planning
• Close monitoring of blood pressure, glucose, and cardiovascular status 5
• Lifelong surveillance after treatment for recurrence and hormonal deficiencies 1