12.9 Surgical Diseases And Dysfunc Of Thyroid Flashcards
Morphology of the thyroid
- diffusely enlarged
- single nodule
- multi nodular goiter (MNG)
- MNG with dominant nodule
Goiter - enlargement in H-shape, wraps around front of windpipe
Functional symptoms of Hyperthyroidism
- Fatigue
- Weight loss
- Diaphoresis
- Palpitations
- Heat intolerance
- Muscle weakness
- Insomnia
- Anxiety
- Restlessness
- Irritability
- Tremor
- Emotional liability
- Diarrhea
Functional symptoms of hypothyroidism
- Fatigue
- Weight gain
- Constipation
- Depression
- Impaired mentation
- Muscle cramps
- Dry skin
- Brittle nails
- Cold intolerance
Thyroid nodules
General
- Neoplastic (Benign incl functioning and non-functioning or Malignant) vs Non-Neoplastic (Hyperplastic and Inflammatory)
- Cold, Warm or Hot
- > 90% are benign
- 4.5 to 6% are malignant
- Approximately 23% of solitary nodules represent a dominant nodule within a multinodular goiter
Thyroid nodules
Presentation
- Asymptomatic/ Incidentaloma
- Mass
- Hypo-/Hyperthyroid evaluation
Thyroid nodules
Risk Factors
- Female gender
- Increased age
- Iron deficiency
- Ionizing radiation
- Obesity
- Alcohol consumption and smoking
- Metabolic Syndrome (down or turner)
- Previous lithium use (for bipolar disorder)
Evaluation for associated symptoms
Factors that are predictors for malignancy:
- Dysphagia (swallowing difficulties)
- Choking
- Palpable lymph nodes
- Pain
- Hoarseness
- Hyperthyroid
- Hypothyroid
Single thyroid nodules: Non-neoplastic
Hyperplastic Nodule
- Hyperplasia of the follicular cells
Colloid nodule
- Thyroid gland is unable to meet metabolic demands of body with sufficient hormone production
- Gland compensates by enlarging (overcomes mild deficiencies
- Accumulation of colloid within the follicles
Cyst (15-25%)
- 15 – 40% of nodules are partially or entirely cystic
- True cysts are rare
- Pseudocysts = necrosis and colliquation
Thyroiditic Nodule
- Nodular Lymphocytic Thyroiditis (NLT):
1) Lymphocyte thyroiditis growing as a nodule in a normal or hyperplastic gland
2) Lymphocyte thyroiditis associated in the same nodule with other nodular disease (eg papillary thyroid carcinoma or lymphoma associated to chronic lymphocytic thyroiditis)
Single thyroid nodules: Neoplastic
Benign:
- Follicular adenoma
Well-differentiated Ca:
- Papillary carcinoma (PTC)
- Follicular carcinoma (FTC)
“Non”-well-differentiated Ca:
- Medullary carcinoma (MTC)
- Anaplastic carcinoma (ATC)
What is a nodular thyroid hyperplasia?
- non-cancerous type of growth involving thyroid gland
- abnormal growth cab affect one-half of gland (one lobe) or entire gland (both lobes and isthmus)
- most common cause of nodules in thyroid gland
Follicular Adenoma
General
Etiology
- Benign (differentiate from follicular carcinoma – poor prognosis)
- Usually present as a solitary thyroid nodule or in association with thyroid hyperplasia or thyroiditis
- 4 – 7% are palpable, incidental detection in 19 -67%
- hypofunctioning thyroid
ETIOLOGY:
- Iodine deficiency
- PTEN hamartoma tumor syndrome (PHTS) includes several syndromes like Cowden syndrome and BRRS.
Follicular adenoma or carcinoma
Presentation
Family Hx of: Autoimmune disease (Graves, Hashimotos thyroiditis), Gardeners disease, thyroid carcinoma
- Occasionally palpable nodule (< 1cm difficult to palpate unless anterior)
- Painless, slow growing mass (unless haemorrhage or cystic degeneration)
- Pressure sx (hoarseness, coughing, choking, dysphagia)
Well differentiated Ca
Papillary (PTC)
Follicular (FTC)
Papillary (PTC)
- Common (80% of carcinomas)
- Peak onset 30 - 50 yrs
- Female:Male – 3:1
- Prognosis related to age and gender (better < 55, female)
- +/- 50% spread to LN, rare distant metastases
- Commonly seen with irradiation therapy
Follicular (FTC)
- 2nd most common (15%)
- More aggressive (> 40 yrs of age)
- Female:Male – 3:1
- Prognosis related to tumour size (better <1cm)
- Vascular invasion (distant metastases common
Not well differentiated Ca
Medullary (MTC)
- Rare (< 3% of presentation)
- Commonly asymptomatic
- Hereditary form from mutation of RET gene (parafollicular C Cells)
Anaplastic (ATC)
- Least common thyroid cancer (1%)
- Arises within a more differentiated thyroid cancer or goitre
- Lymphnode spread common (90% of cases)
- Can be a rapidly enlarging mass
Clinical predictors of malignancy
- Extremes of age
- Male
- Radiotherapy as a child (Hodgkins Lymphoma)
- Family hx of thyroid carcinoma
- Inherited syndromes associated with thyroid carcinoma (MEN, FAP, Gardener, Cowden’s)
- Rapid growth nodule
- Pain
- Immobility with swallowing
- Hoarseness
- Palpable lymphnodes
