# Clinical Cases: Thyroid Disorders

## Case 1: Graves Disease

### Patient Demographics
- **Age:** 34 years
- **Sex:** Female
- **Occupation:** Marketing manager

### Chief Complaint
"I've lost 15 pounds without trying, my heart races all the time, and I can't tolerate the heat."

### History of Present Illness
A 34-year-old woman presents with a 4-month history of unintentional weight loss despite increased appetite, palpitations, heat intolerance, and excessive sweating. She reports feeling anxious, irritable, and has noticed tremor in her hands. She has difficulty sleeping and feels fatigued despite sleeping 8 hours. Her menstrual periods have become lighter and irregular. Her colleagues have commented that her eyes appear more prominent. She has a family history of thyroid disease (mother with Hashimoto's thyroiditis).

### Physical Examination
- **Vital Signs:** BP 138/62 mmHg (widened pulse pressure), HR 108 bpm (regular), Temp 37.3°C
- **General:** Anxious, fidgety, thin-appearing woman
- **Eyes:** Bilateral proptosis (exophthalmos), lid retraction, lid lag, conjunctival injection
- **Neck:**
  - Diffusely enlarged thyroid gland (2x normal)
  - Non-tender, smooth texture
  - Thyroid bruit audible
- **Cardiovascular:** Tachycardia, hyperdynamic precordium
- **Extremities:** Fine tremor with arms extended, warm and moist palms
- **Skin:** Warm, moist, pretibial myxedema (waxy, non-pitting plaques on anterior shins)
- **Reflexes:** Hyperactive with rapid relaxation phase

### Workup
- **Laboratory Studies:**
  - TSH: <0.01 mIU/L (suppressed)
  - Free T4: 4.8 ng/dL (elevated, normal 0.9-1.7)
  - Free T3: 12.6 pg/mL (elevated, normal 2.3-4.2)
  - TSH receptor antibodies (TRAb/TSI): Strongly positive
  - Anti-TPO antibodies: Positive
- **Thyroid Uptake and Scan:** Diffusely increased uptake (45%, normal 10-30%), homogeneous uptake
- **ECG:** Sinus tachycardia

### Diagnosis
**Graves disease** with:
1. Hyperthyroidism
2. Graves ophthalmopathy (orbitopathy)
3. Pretibial myxedema (dermopathy)

### Treatment
1. **Symptomatic relief:**
   - Beta-blocker (propranolol 20-40 mg TID) for tachycardia, tremor, anxiety
2. **Definitive treatment options:**
   - **Antithyroid drugs (ATDs):**
     - Methimazole 10-20 mg daily (preferred) OR
     - Propylthiouracil (PTU) 100 mg TID (preferred in 1st trimester pregnancy)
     - Trial for 12-18 months; ~30-50% remission rate
   - **Radioactive iodine (I-131):**
     - Preferred in US for definitive treatment
     - Results in hypothyroidism (intentional)
   - **Thyroidectomy:**
     - For large goiter, suspicious nodules, or patient preference
3. **Ophthalmopathy management:**
   - Lubricating eye drops
   - Smoking cessation (critical)
   - Glucocorticoids for moderate-severe disease
   - Orbital decompression for severe cases
   - Teprotumumab (IGF-1R inhibitor) for moderate-severe active disease
4. **Monitoring:** TSH, free T4 every 4-6 weeks until stable

### Clinical Pearl
Graves disease is an autoimmune condition caused by TSH receptor-stimulating antibodies (TSI) that mimic TSH action. It is the most common cause of hyperthyroidism in iodine-sufficient regions. The classic triad of Graves disease is hyperthyroidism, ophthalmopathy, and dermopathy, though not all patients have all three features. Ophthalmopathy can worsen after radioactive iodine treatment, especially in smokers; this can be prevented with glucocorticoid prophylaxis in high-risk patients. Methimazole is preferred over PTU except in first trimester pregnancy (PTU) and thyroid storm (PTU blocks peripheral T4→T3 conversion).

### Clinical Image
![Graves Ophthalmopathy](case_01_image.jpg)

*Bilateral exophthalmos (proptosis) characteristic of Graves ophthalmopathy, showing lid retraction and scleral show.*

**Image Source:** Wikimedia Commons - "Graves disease ophthalmopathy"
**License:** CC BY-SA 3.0
**URL:** https://commons.wikimedia.org/wiki/File:Proptosis_and_lid_retraction_from_Graves%27_Disease.jpg

---

## Case 2: Hashimoto's Thyroiditis with Hypothyroidism

### Patient Demographics
- **Age:** 42 years
- **Sex:** Female
- **Occupation:** Librarian

### Chief Complaint
"I'm exhausted all the time, I've gained weight, and I'm always cold."

### History of Present Illness
A 42-year-old woman presents with a 6-month history of progressive fatigue, weight gain (12 pounds), cold intolerance, and constipation. She reports feeling "slowed down" mentally, with difficulty concentrating and memory problems. Her voice has become hoarse, and her skin and hair have become dry. She has noticed swelling in her face and hands. Her menstrual periods have become heavier and more frequent. She has a sister with type 1 diabetes.

### Physical Examination
- **Vital Signs:** BP 142/92 mmHg, HR 56 bpm, Temp 36.2°C
- **General:** Overweight, fatigued-appearing woman with slow movements and speech
- **Face:** Periorbital puffiness, dry, coarse features
- **Neck:**
  - Thyroid gland firm, rubbery, diffusely enlarged (1.5x normal)
  - Non-tender, irregular/pebbly texture
  - No nodules, no bruit
- **Cardiovascular:** Bradycardia, distant heart sounds
- **Skin:** Dry, cool, rough texture; non-pitting edema of hands and face (myxedema)
- **Hair:** Coarse, brittle; lateral eyebrow thinning
- **Reflexes:** Delayed relaxation phase ("hung-up" reflexes)

### Workup
- **Laboratory Studies:**
  - TSH: 68 mIU/L (markedly elevated)
  - Free T4: 0.4 ng/dL (low)
  - Anti-TPO antibodies: >1000 IU/mL (markedly elevated)
  - Anti-thyroglobulin antibodies: 245 IU/mL (elevated)
  - Lipid panel: Total cholesterol 268 mg/dL, LDL 178 mg/dL (elevated)
- **CBC:** Hemoglobin 10.8 g/dL (mild anemia)
- **Ultrasound Thyroid:** Diffusely heterogeneous, hypoechoic gland with increased vascularity; no discrete nodules

### Diagnosis
**Hashimoto's thyroiditis** (chronic lymphocytic thyroiditis) with overt primary hypothyroidism

### Treatment
1. **Levothyroxine replacement:**
   - Starting dose: 1.6 mcg/kg/day (full replacement) in otherwise healthy patients
   - In elderly or cardiac patients: Start low (25-50 mcg) and titrate slowly
   - Take on empty stomach, 30-60 minutes before breakfast or at bedtime
2. **Monitoring:**
   - Recheck TSH in 6-8 weeks
   - Titrate levothyroxine by 12.5-25 mcg increments
   - Goal: TSH in normal range (usually 0.5-2.5 mIU/L)
3. **Long-term:**
   - Annual TSH monitoring once stable
   - Watch for drug interactions (calcium, iron, PPI)
   - Screen for other autoimmune conditions (celiac, adrenal insufficiency)

### Clinical Pearl
Hashimoto's thyroiditis is the most common cause of hypothyroidism in iodine-sufficient regions and is characterized by lymphocytic infiltration of the thyroid with positive anti-TPO and/or anti-thyroglobulin antibodies. It is associated with other autoimmune conditions (type 1 diabetes, celiac disease, vitiligo, Addison's disease). The delayed relaxation phase of reflexes (pseudo-myotonic reflex) is a classic finding of hypothyroidism. Levothyroxine absorption is affected by many factors - patients should be counseled about consistent timing, avoiding calcium/iron supplements within 4 hours, and informing their doctor of any new medications.

### Clinical Image
![Hashimoto's Thyroid Ultrasound](case_02_image.jpg)

*Thyroid ultrasound showing diffusely heterogeneous, hypoechoic parenchyma with fibrous bands characteristic of Hashimoto's thyroiditis.*

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

---

## Case 3: Thyroid Storm

### Patient Demographics
- **Age:** 28 years
- **Sex:** Female
- **Occupation:** Graduate student

### Chief Complaint
"My daughter has high fever, is confused, and her heart is racing."

### History of Present Illness
A 28-year-old woman with known Graves disease (diagnosed 1 year ago, non-adherent with methimazole) is brought to the emergency department by her mother. She developed a urinary tract infection 3 days ago and was started on antibiotics. Over the past 24 hours, she became increasingly agitated, confused, and developed high fever. She has been vomiting and having diarrhea. On arrival, she is diaphoretic, tremulous, and unable to answer questions coherently. Her mother confirms she stopped taking her methimazole 2 months ago because of side effects.

### Physical Examination
- **Vital Signs:** BP 160/60 mmHg (widened pulse pressure), HR 168 bpm (irregular), Temp 40.2°C, RR 28/min
- **General:** Severely ill-appearing, agitated, diaphoretic
- **Mental Status:** Confused, disoriented, picking at bedsheets
- **Eyes:** Proptosis, lid lag
- **Neck:** Diffusely enlarged thyroid, thyroid bruit
- **Cardiovascular:** Tachycardia with irregular rhythm (atrial fibrillation), hyperdynamic precordium
- **Abdomen:** Hyperactive bowel sounds, mild tenderness
- **Skin:** Hot, flushed, diaphoretic
- **Extremities:** Marked tremor

### Workup
- **Laboratory Studies:**
  - TSH: <0.01 mIU/L
  - Free T4: 7.8 ng/dL (markedly elevated)
  - Free T3: 22.4 pg/mL (markedly elevated)
  - Glucose: 156 mg/dL
  - AST/ALT: Mildly elevated
  - Bilirubin: 2.1 mg/dL (elevated)
  - WBC: 14,000/μL
- **ECG:** Atrial fibrillation with rapid ventricular response
- **Burch-Wartofsky Score:** >45 (highly suggestive of thyroid storm)

### Diagnosis
**Thyroid storm** precipitated by infection in uncontrolled Graves disease

### Treatment
**IMMEDIATE - this is a medical emergency with 10-30% mortality:**

1. **Block thyroid hormone synthesis:**
   - PTU 500-1000 mg loading dose, then 250 mg every 4 hours (preferred in storm - also blocks peripheral T4→T3 conversion)
2. **Block thyroid hormone release (give 1 hour AFTER PTU):**
   - Potassium iodide (SSKI) 5 drops every 6 hours OR
   - Lugol's solution 10 drops every 8 hours
3. **Block peripheral conversion and effects:**
   - Propranolol IV 1 mg slow push, repeat as needed; OR esmolol drip
   - High-dose propranolol also blocks T4→T3 conversion
4. **Block T4→T3 conversion additionally:**
   - Hydrocortisone 100 mg IV every 8 hours (also treats possible relative adrenal insufficiency)
5. **Supportive care:**
   - Aggressive cooling (acetaminophen, cooling blankets - avoid aspirin as it displaces T4 from binding proteins)
   - IV fluids
   - Treat precipitating cause (antibiotics for UTI)
   - ICU admission
6. **Once stable:** Continue PTU, consider definitive therapy (RAI or surgery)

### Clinical Pearl
Thyroid storm is a life-threatening exacerbation of hyperthyroidism with multi-organ dysfunction. The Burch-Wartofsky score helps assess probability based on temperature, CNS effects, GI/hepatic dysfunction, cardiovascular dysfunction, heart failure, and precipitant history. Treatment follows the mnemonic "PPTB" - PTU (synthesis), Potassium iodide (release), (proprano)Lol (effects), Beta-blocker. Iodide must be given at least 1 hour after antithyroid drug to prevent using the iodine as substrate for new hormone synthesis. Glucocorticoids are important because thyroid hormone increases cortisol metabolism, and these patients may have relative adrenal insufficiency.

### Clinical Image
![Thyroid Storm Treatment Algorithm](case_03_image.jpg)

*Treatment algorithm for thyroid storm showing the sequence of medications and their mechanisms of action.*

**Image Source:** Wikimedia Commons - "Thyroid storm management"
**License:** CC BY-SA 4.0
**URL:** https://commons.wikimedia.org/wiki/File:Hyperthyroidism_treatment_diagram.svg