# Clinical Cases: Anterior Pituitary Disorders

## Case 1: Acromegaly

### Patient Demographics
- **Age:** 45 years
- **Sex:** Male
- **Occupation:** Software engineer

### Chief Complaint
"My wedding ring doesn't fit anymore, and my shoes are two sizes bigger than they were five years ago."

### History of Present Illness
A 45-year-old man presents to his primary care physician after noticing progressive changes in his appearance over the past several years. He reports that his hands and feet have enlarged, requiring larger gloves and shoes. His wife has commented that his facial features have become "coarser." He has developed excessive sweating, joint pain in his knees and hips, and has been told he snores loudly with episodes of apnea. He was recently diagnosed with type 2 diabetes and hypertension. Old photographs from 10 years ago show distinctly different facial features.

### Physical Examination
- **Vital Signs:** BP 152/94 mmHg, HR 78 bpm
- **General:** Large, prominent facial features; enlarged hands and feet
- **HEENT:** Frontal bossing, prognathism (jaw protrusion), macroglossia, widely spaced teeth, thickened lips and nose
- **Cardiovascular:** S4 gallop present
- **Extremities:** Soft tissue swelling of hands and feet, doughy feel to skin
- **Skin:** Oily, skin tags present
- **Neurologic:** Bilateral carpal tunnel syndrome symptoms

### Workup
- **Laboratory Studies:**
  - IGF-1: 856 ng/mL (markedly elevated for age, normal 75-216)
  - Random GH: 18 ng/mL (elevated, normal <1 ng/mL)
  - Oral Glucose Tolerance Test (OGTT): GH nadir 8.2 ng/mL (fails to suppress below 1 ng/mL)
  - Prolactin: 42 ng/mL (mildly elevated - co-secretion or stalk effect)
  - Fasting glucose: 142 mg/dL
  - HbA1c: 7.2%
- **MRI Pituitary with Contrast:** 1.8 cm pituitary macroadenoma

### Diagnosis
**Acromegaly** due to GH-secreting pituitary adenoma (somatotroph adenoma)

### Treatment
1. **First-line:** Transsphenoidal surgical resection
2. **If not cured surgically:**
   - Somatostatin analogs (octreotide LAR, lanreotide)
   - GH receptor antagonist (pegvisomant)
   - Dopamine agonist (cabergoline) - especially if prolactin co-secretion
3. **Radiation therapy** for refractory cases
4. **Management of comorbidities:** Diabetes, hypertension, sleep apnea
5. **Colonoscopy** screening (increased risk of colon polyps/cancer)

### Clinical Pearl
The diagnosis of acromegaly is often delayed 7-10 years from symptom onset because changes are gradual and insidious. IGF-1 is the best screening test as it reflects integrated GH secretion over 24 hours. Confirmation requires demonstrating failure of GH suppression during an oral glucose tolerance test (GH should normally suppress to <1 ng/mL). Mortality in acromegaly is primarily due to cardiovascular disease, with patients having a 2-3 fold increased risk of death if GH/IGF-1 levels are not controlled.

### Clinical Image
![Acromegaly Facial Features](case_01_image.jpg)

*Comparison photographs showing progressive coarsening of facial features in acromegaly over years, with frontal bossing, prognathism, and soft tissue enlargement.*

**Image Source:** Wikimedia Commons - "Acromegaly facial features"
**License:** CC BY-SA 3.0
**URL:** https://commons.wikimedia.org/wiki/File:Acromegaly_facial_features.JPEG

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## Case 2: Prolactinoma with Amenorrhea-Galactorrhea Syndrome

### Patient Demographics
- **Age:** 28 years
- **Sex:** Female
- **Occupation:** Marketing consultant

### Chief Complaint
"I haven't had my period in 8 months and I'm leaking milk from my breasts."

### History of Present Illness
A 28-year-old woman presents with secondary amenorrhea for 8 months and bilateral breast discharge for 4 months. She is not pregnant (multiple negative pregnancy tests) and is not taking any medications that could cause these symptoms. She reports decreased libido and has noticed occasional headaches. She and her husband have been trying to conceive for the past year without success. She denies visual changes.

### Physical Examination
- **Vital Signs:** BP 116/72 mmHg, HR 68 bpm
- **General:** Well-appearing woman in no distress
- **Breast:** Bilateral milky discharge expressible from multiple ducts
- **Pelvic:** Normal external genitalia, vaginal mucosa appears slightly atrophic
- **Visual Fields:** Full to confrontation
- **Neurologic:** Normal

### Workup
- **Laboratory Studies:**
  - Prolactin: 186 ng/mL (markedly elevated, normal <25)
  - β-hCG: Negative
  - TSH: 2.1 mIU/L (normal)
  - FSH: 3.2 mIU/mL (low)
  - LH: 2.8 mIU/mL (low)
  - Estradiol: 22 pg/mL (low)
- **MRI Pituitary with Contrast:** 12 mm pituitary adenoma (macroadenoma) confined to sella

### Diagnosis
**Prolactinoma** (macroprolactinoma) causing:
1. Galactorrhea
2. Secondary amenorrhea (hypogonadotropic hypogonadism)
3. Infertility

### Treatment
1. **First-line: Dopamine agonist therapy**
   - Cabergoline 0.25-0.5 mg twice weekly (preferred - more effective, fewer side effects)
   - Alternative: Bromocriptine 2.5 mg daily
2. **Goals:** Normalize prolactin, restore menstrual function, reduce tumor size
3. **Follow-up:** Repeat prolactin in 1 month, MRI in 3-6 months
4. **Pregnancy considerations:** Can attempt conception once prolactin normalizes; discontinue cabergoline when pregnant
5. **Surgery reserved for:** Medication intolerance or resistance

### Clinical Pearl
Prolactinomas are the most common functioning pituitary adenomas (40% of all pituitary tumors). Unlike other pituitary adenomas, the first-line treatment is medical therapy with dopamine agonists, not surgery. Cabergoline is preferred over bromocriptine due to better efficacy and tolerability. The degree of prolactin elevation generally correlates with tumor size - a "stalk effect" from non-functioning adenomas typically causes prolactin levels <100 ng/mL, while true prolactinomas cause elevations proportional to tumor mass. A 12mm tumor with prolactin of only 40-50 ng/mL should raise suspicion for a non-functioning adenoma with stalk effect.

### Clinical Image
![Prolactinoma MRI](case_02_image.jpg)

*Coronal T1-weighted MRI with gadolinium showing a pituitary macroadenoma consistent with prolactinoma.*

**Image Source:** Radiopaedia - "Prolactinoma"
**License:** CC BY-NC-SA 3.0
**URL:** https://radiopaedia.org/cases/prolactinoma-3

---

## Case 3: Cushing Disease

### Patient Demographics
- **Age:** 38 years
- **Sex:** Female
- **Occupation:** Elementary school teacher

### Chief Complaint
"I've gained 30 pounds in my trunk despite dieting, and I bruise at the slightest touch."

### History of Present Illness
A 38-year-old woman presents with a 2-year history of progressive weight gain (30 lbs), predominantly in her abdomen and face, despite attempts at diet and exercise. She has noticed easy bruising, facial plethora, and development of purple streaks on her abdomen. She reports proximal muscle weakness, difficulty climbing stairs and getting up from chairs. She has developed new-onset hypertension and was recently diagnosed with type 2 diabetes. She also reports mood changes with irritability and depression, as well as irregular menstrual periods.

### Physical Examination
- **Vital Signs:** BP 158/96 mmHg, HR 82 bpm
- **General:** Central obesity with relatively thin extremities
- **Face:** Moon facies, facial plethora, mild hirsutism
- **Skin:** Thin skin, multiple ecchymoses, wide (>1 cm) violaceous striae on abdomen
- **Back:** Dorsocervical fat pad ("buffalo hump"), supraclavicular fat pads
- **Extremities:** Proximal muscle weakness (difficulty rising from squat), thin arms and legs with muscle wasting
- **Neurologic:** Mild proximal weakness 4/5

### Workup
- **Initial Screening Tests:**
  - 24-hour urine free cortisol: 486 μg/24h (elevated, normal <50)
  - Late-night salivary cortisol: 0.52 μg/dL (elevated, normal <0.09)
  - 1 mg overnight dexamethasone suppression test: AM cortisol 14.2 μg/dL (fails to suppress <1.8)
- **ACTH Level:** 58 pg/mL (normal/elevated - indicating ACTH-dependent)
- **High-dose dexamethasone suppression test:** >50% suppression of cortisol
- **MRI Pituitary with Contrast:** 6 mm microadenoma in left side of pituitary
- **Inferior petrosal sinus sampling (if MRI inconclusive):** ACTH central-to-peripheral gradient >3:1 after CRH stimulation

### Diagnosis
**Cushing disease** (ACTH-secreting pituitary adenoma causing hypercortisolism)

### Treatment
1. **First-line:** Transsphenoidal surgical resection of pituitary adenoma
2. **Post-operative management:**
   - Monitor for adrenal insufficiency (hypothalamic-pituitary-adrenal axis suppression)
   - Glucocorticoid replacement until axis recovers
3. **If surgery fails or recurrence:**
   - Repeat surgery
   - Radiation therapy (conventional or stereotactic)
   - Medical therapy: Pasireotide, cabergoline, ketoconazole, metyrapone, osilodrostat
   - Bilateral adrenalectomy (last resort - risk of Nelson syndrome)
4. **Management of comorbidities:** Diabetes, hypertension, osteoporosis, psychiatric symptoms

### Clinical Pearl
Cushing disease specifically refers to ACTH-dependent hypercortisolism caused by a pituitary adenoma, while Cushing syndrome is the broader term for hypercortisolism of any cause. The diagnostic workup follows a stepwise approach: (1) confirm hypercortisolism with 24-hour urine free cortisol, late-night salivary cortisol, or low-dose dexamethasone suppression test; (2) determine if ACTH-dependent or independent by measuring ACTH; (3) if ACTH-dependent, localize the source (pituitary vs. ectopic). Wide violaceous striae (>1 cm) are highly specific for Cushing syndrome and help distinguish pathologic hypercortisolism from simple obesity.

### Clinical Image
![Cushing Syndrome Features](case_03_image.jpg)

*Clinical photograph demonstrating characteristic features of Cushing syndrome including moon facies, central obesity, and abdominal striae.*

**Image Source:** Wikimedia Commons - "Cushing syndrome"
**License:** CC BY-SA 4.0
**URL:** https://commons.wikimedia.org/wiki/File:Cushing_syndrome.jpg