PANCE Blueprint Endocrinology (6%)

Diseases of the Thyroid Gland (PEARLS)

The NCCPA™ Content Blueprint covers 6 endocrine topics related to the thyroid

Hyperparathyroidism Etiology: Parathyroid adenoma

Presentation: “stones, bones, abdominal groans, psych moans, fatigue overtones”

  • Nephrolithiasis, DI, bone pain, arthralgia, PUD, constipation,depression, fatigue

Labs: Hypercalcemia ↑ CA+, hypophosphatemia, elevated ↑ PTH and moderately elevated urinary calcium

Treatment:

  • Acute- Saline, calcitonin, bisphosphonates
  • Definitive- Surgical correction. Remove overactive parathyroid gland. If all 4, remove 3.5 glands.
Hypoparathyroidism Etiology: Thyroidectomy

Presentation: Tingling, Tetany, cataracts

Physical exam:

Labs: Hypocalcemia ↓ CA+, low ↓ PTH , hyperphosphatemia, low urinary calcium

Treatment: Vitamin D and Calcium

  • Tetany- secure airway, IV calcium gluconate
Hyperthyroidism (ReelDx) Etiology: Grave’s disease (autoimmune). Toxic adenoma, thyroiditis, pregnancy, amiodarone

Presentation: Heat intolerance, palpitations, sweating, weight loss, tremor, anxiety, tachycardia

  • Graves- Diffuse goiter with a bruit, exophthalmos, pretibial myxedema
  • Thyroid storm- Fever, tachycardia, delirium

Diagnosis:

  • TSH (best test): Decreased in primary disease (↓ TSH  and ↑ Free T4), elevated in secondary disease (↑ TSH  and ↑ Free T4)
  • T4: Elevated although may be normal
  • Thyroid radioactive iodine uptake:
    • Graves: Diffusely high uptake
    • Toxic multinodular: Discrete areas of high uptake

Antibodies:

  • Graves: Anti-thyrotropin antibodies

Treatment:

  • Beta blockers (symptomatic), methimazole/propylthiouracil, radioactive iodine, thyroidectomy
  • Thyroid storm- prompt beta blockers, hydrocortisone, methimazole/propylthiouracil, iodine
  • Thyroidectomy- most likely complication is recurrent laryngeal nerve (hoarseness)

Antithyroid drugs during pregnancy — Propylthiouracil used to be the drug of choice during pregnancy because it causes less severe birth defects than methimazole. But experts now recommend that propylthiouracil be given during the first trimester only. This is because there have been rare cases of liver damage in people taking propylthiouracil. After the first trimester, women should switch to methimazole for the rest of the pregnancy.

For women who are nursing, methimazole is probably a better choice than propylthiouracil (to avoid liver side effects).

Hypothyroidism Etiology: Hashimoto’s (chronic lymphocytic/autoimmune), previous thyroidectomy/iodine ablation, congenital

Presentation:

  • Cold intolerance, fatigue, constipation, depression, weight gain, bradycardia
  • Congenital: round face, large tongue, hernia, delayed milestones, poor feeding

Labs: TSH- elevated in primary disease. Low T4 (↑ TSH and ↓ Free T4)

  • Hashimoto’s- Antithyroid peroxidase, antithyroglobulin antibodies

Treatment: Levothyroxine. Follow up with serial TSH monitoring

Thyroid neoplastic disease Hoarse voice, cold nodule on thyroid uptake scan!

Most often papillary carcinoma

Diagnostic studies:

  • Normal thyroid function. Solitary hard, cold nodule
  • Fine needle biopsy for definitive diagnosis

Treatment: Surgical resection

Thyroiditis Painful vs. painless may be hypo or hyperthyroid

Hashimoto’s thyroiditis:

  • Diffusely enlarged, nodular goiter

Subacute thyroiditis:

  • Young women, viral cause
  • Painful enlarged thyroid with dysphagia, mild fever
  • Treatment: Aspirin

Postpartum thyroiditis:

  • 1-2 months of hyperthyroidism after delivery
  • Treatment: Completely resolves, give propranolol for cardiac symptoms

Suppurative:

  • Fever, pain, redness, fluctuant mass
  • Treatment: Antibiotic/surgical drainage
IM_MED_ThyroidFunctionScreeningTests_v1.2 When a patient is suspected of having an underlying thyroid condition, there is a stepwise approach to ordering thyroid function tests. The initial screening test of choice is the measurement of thyroid stimulating hormone or TSH. Depending on the value determined, measurements of thyroid hormones (serum free T3 and free T4) may be taken, with the addition of a total T4 measurement to provide further evidence towards the underlying cause. Regardless of etiology, screening tests are not always reliable in a severely ill inpatient population, and special circumstances, like pregnancy, may alter the measured value of these tests.

Thyroid Function Screening Tests Picmonic

parathyroid-gland_5110_1472585798 The parathyroid gland is a series of four small glands located in the neck on the rear surface of the thyroid gland. It serves primarily in calcium homeostasis and has a blood calcium sensor that detects when blood calcium levels are abnormally low. It responds by releasing parathyroid hormone (PTH) which stimulates osteoclasts into action. Osteoclasts resorb bone and release a large amount of calcium. This calcium enters the blood and results in increased blood calcium levels. PTH can also activate vitamin D by promoting the activity of an enzyme that converts inactive vitamin D to active vitamin D

Parathyroid Gland Overview Picmonic

thyroid-gland_5109_1475535516 The thyroid gland is a large endocrine gland that is located in the neck. It releases T3 and T4 hormones, which help the body regulate metabolism. T3 and T4 stand for triiodothyronine (T3) and thyroxine, which can sometimes be referred to as tetraiodothyronine (T4). In addition, the thyroid gland has a blood calcium sensor that helps it detect when blood calcium levels are elevated, to which it responds. The thyroid gland releases calcitonin, which builds bone, resulting in an absorption of calcium from the bloodstream. Osteoblasts are the cells responsible for bone formation.

Thyroid Gland Overview Picmonic

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