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Endocrine Glands and Breast Lecture Notes

Endocrine Glands Overview

  • Definition: Endocrine glands are responsible for producing and secreting hormones that regulate various bodily functions.
  • Main Glands: Includes pituitary, thyroid, parathyroid, adrenal glands, and the endocrine pancreas, as well as ovaries and testes.

Pituitary Gland

  • Anatomy: Divided into anterior (adenohypophysis) and posterior (neurohypophysis) lobes.
  • Origin: Anterior from Rathke's pouch; posterior from the brain.
  • Functions:
    • Anterior Pituitary: Produces TSH, ACTH, LH, FSH, GH, and prolactin.
      • Effects include:
      • Growth hormone: stimulates bone growth.
      • TSH: stimulates thyroid gland.
      • ACTH: stimulates adrenal cortex.
      • Gonadotropic hormones (LH/FSH): stimulate gonads.
      • Prolactin: stimulates mammary glands.
    • Posterior Pituitary: Stores and releases oxytocin and vasopressin (ADH), produced in supraoptic and paraventricular nuclei.

Pituitary Tumors

  • Common Types:
    • Microadenomas: less than 1 cm.
    • Macroadenomas: greater than 1 cm.
  • Symptoms: Depend on hormone secreted
    • Prolactinoma: galactorrhea, breast development.
    • Growth hormone adenoma: gigantism/acromegaly.
    • ACTH secreting adenoma: Cushing's disease.
  • Visual Deficits: Pituitary tumors can cause bitemporal hemianopsia due to pressure on the optic chiasm.
  • Diagnosis: Hormonal level tests, CT or MRI scans.
  • Treatment: Depends on type; could include medication (bromocriptine for prolactinomas), surgery, or radiation.

Thyroid Gland

  • Embryology: Develops from the base of the tongue, may leave a remnant (thyroglossal cyst).
  • Anatomy: Comprised of two lobes connected by an isthmus; has paired arteries and veins.
  • Hormone Production: Produces thyroxine (T3 and T4), calcitonin (lowers blood calcium levels).
  • Hypothyroidism:
    • Causes: Iodine deficiency, autoimmune diseases (Hashimoto's), surgery.
    • Symptoms: Fatigue, weight gain, cold intolerance.
  • Hyperthyroidism:
    • Causes: Graves' disease, toxic nodular goiter.
    • Symptoms: Weight loss, heat intolerance, tremors.

Thyroid Cancer

  • Types:
    • Papillary: Most common, often excellent prognosis.
    • Follicular/Herzle Cell: Requires total thyroidectomy, may present with invasion.
    • Medullary: Arises from C-cells, familial syndromes.
    • Anaplastic: Very aggressive, poor prognosis.
  • Diagnosis: Biopsies (FNA), imaging studies.

Parathyroid Glands

  • Anatomy: Typically four glands located behind thyroid.
  • Function: Regulate calcium and phosphate levels through parathyroid hormone (PTH) secretion.
  • Hyperparathyroidism: Presents with “stones, bones, abdominal groans, and psychiatric overtones.”
    • Primary Causes: Adenoma, hyperplasia.
  • Diagnosis: Elevated calcium and PTH levels.

Endocrine Pancreas

  • Cell Types: Alpha (glucagon), beta (insulin), delta (somatostatin), and pancreatic polypeptide cells.
  • Insulinomas: Present with Whipple's triad; diagnosed with CT or MRI.
  • Gastrinomas: Cause Zollinger-Ellison syndrome; located in the gastrinoma triangle.
  • VIPomas: Cause profuse diarrhea.
  • Glucagonomas: Associated with necrolytic migratory erythema.

Adrenal Glands

  • Anatomy: Outer cortex (aldosterone, glucocorticoids) and inner medulla (catecholamines).
  • Cushing's Syndrome: Features truncal obesity, hypertension, and diabetes; due to ACTH secretion.
  • Addison's Disease: Adrenal insufficiency; presents with fatigue, weight loss, and electrolyte imbalances.
  • Pheochromocytoma: Associated with hypertension, headaches, anxiety; must treat high blood pressure pre-surgery.

Breast Anatomy and Related Disorders

  • Anatomy Overview: Modified sweat gland; has Cooper's ligaments and lactiferous ducts.
  • Development: Changes during puberty and pregnancy.
  • Benign Disorders: Fibroadenoma, cysts (galactocele), mastitis, and gynecomastia.
  • Breast Cancer:
    • Risk Factors: Age, family history, genetic mutations (BRCA1, BRCA2).
    • Diagnosis: Clinical history, imaging (mammography, ultrasound), and biopsy.
    • Types: DCIS, LCIS, invasive ductal/lobular carcinoma.

Breast Cancer Treatment

  • Surgical Options: Lumpectomy, mastectomy with sentinel node biopsy; increasingly less radical than in previous decades.
  • Adjunct Treatments:
    • Chemotherapy: Neoadjuvant to shrink for surgery, or adjuvant for additional treatment post-schema.
    • Hormonal Treatments: Tamoxifen, aromatase inhibitors for ER-positive cancers.
    • Radiation Therapy: Often after lumpectomy to control local disease.

Summary of Important Concepts

  • Review risk factors for endocrine disorders and breast diseases, especially familial links.
  • Pay attention to the differences between benign and malignant conditions—both in presentation and management.
  • Understand the treatment and prognosis associated with various types of hormone-producing tumors, and breast cancers.