The THYROID Gland

ANATOMY & LOCATION

Brownish-red and soft during life.

Butterfly shaped

Endocrine Gland

Divided into Right & Left lobes, connected by an Isthmus

Located in the neck, medially and anterior to CCA (Common Carotid

Artery) and IJV (Internal Jugular Vein)

Pyramidal lobe (normal variant): Superior extension of the Isthmus

Contains follicles that contain a fluid called “Colloid”

Pyramidal lobe

PHYSIOLOGY

Hypothalamus produces thyroid-releasing hormone

Thyroid-releasing hormone controls the release of

Thyroid-stimulating hormone by the Pituitary gland

Thyroid-stimulating hormone causes Thyroid to

release hormones in its cells.

1. Thyroxine (T4)

2. Triiodothyronine (T3)

3. Calcitonin

PHYSIOLOGY Thyrotropin “Thyroid-stimulating hormone” TSH:

Controlled by Pituitary gland

Produces hormones called:1. Thyroxine (T4): Aids in metabolism of fats, proteins, carbohydrates2. Triiodothyronine (T3): Aids in metabolism of fats, proteins,

carbohydrates3. Calcintonin: Removes calcium in the blood for storage in bones

Uses Iodine, found in vegetables, seafood, and iodized salt to create these hormones

Regulates metabolism so your cells function properly

Affects every cell in the body

Organs affected by Thyroid Hormones:1. Eyes2. Lungs3. Heart4. GI Tract5. Liver6. Uterus7. Skin8. Kidney9. Brain

PATHOLOGY

Goiter: Enlarged Thyroid gland

Hyperthyroidism; Grave’s disease

Hypothyroidism; Hashimoto disease

PATHOLOGY

Goiter - Enlarged, hyperplastic thyroid gland:

An Isthmus that is greater than 10mm indicates an enlarged Thyroid

Thru Ultrasound, an enlarged Thyroid will appear Heterogenous w/

(multiple) cystic and solid components (Adenomatous goiter)

PATHOLOGY

Hyperthyroidism - Overproduction of Thyroid hormones

Signs: Bulging eyes, Heat intolerance, Nervousness, Weight loss, Hair loss

Thru Ultrasound, Thyroid will appear Heterogenous or Hypoechoic with

hypervascularity throughout the gland

Grave’s disease

PATHOLOGYHypothyroidism – Underproduction of Thyroid hormones

Signs: Depression, Sensitive to cold, Elevated blood cholesterol levels, Slight weight gain

Thyroid becomes inflamed, resulting in smaller amounts of thyroid hormones (causing the

Pituitary gland to produce more TSH)

Thru Ultrasound, Thyroid will appear diffusely heterogenous, enlarged, vascular, with

hypoechoic nodules

Hashimoto disease

PATHOLOGYBenign Thyroid Nodules – Common masses, identified with sonography

Considered as Follicular adenomas (most common benign neoplasms) or Hyperplastic

nodules (adenomatous nodules) are multiple and vary in sonographic appearance

Characteristics: Cystic components, less than 5mm, hyperechoic mass, ‘eggshell’

calcifications, ‘hot’ (NM)

PATHOLOGYMalignant Thyroid Nodules – Thyroid cancer

Papillary carcinoma is the most common type of Thyroid cancer

Other types: Follicular carcinoma, Medullary carcinoma, Anaplastic carcinoma,

lymphoma, thyroid metastases

Characteristics: Hypoechoic mass, Mass with calcification, Solitary mass, Enlarged

cervical lymph nodes, irregular margins, internal vascularity of nodule, shape-taller than

wide, ‘cold’ (NM)

PARATHYROID GLANDS, CERVICAL LYMPH NODES, OTHER NECK MASSES Parathyroid Glands – Located on the posterior of each lobe on the middle and inferior poles

1. Serve as calcium regulators, control the release and absorption of calcium by the PTH. 2. Hypocalcemia: Decreased levels of serum calcium3. Hypercalcemia: Elevated levels of serum calcium

Pathology: Parathyroid Adenoma – Elevated Serum calcium and PTHSonographic Appearance - Hypo echoic mass near Thyroid

Cervical Lymph Nodes – Can be found during routine neck sonography1. Usually measure less than 1cm.2. Oblong shaped, hypoechoic with echogenic hilum

Pathology: Cervical Lymphadenopathy - Enlarged cervical lymph nodesSonographic Appearance – Enlarged, greater than 1cm, Round, No echogenic hilum, Calficiations

Other Neck Masses1. Thyroglossal Duct Cyst: Benign congenital cyst. Superior to Thyroid, near Hyoid bone. Palpable

Sonographic Appearance: Anechoic, well-defined, unilocular, with posterior enhancement

2. Brachial Cleft Cyst: Benign congenital cyst. Found near angle of mandible. PalpableSonography Appearance: Anechoic

PARATHYROID GLANDS, CERVICAL LYMPH NODES, OTHER NECK MASSES

MODALITIES: NUCLEAR MEDICINE & SONOGRAPHY Nuclear Medicine - Nuclear medicine specialists use safe, painless, and cost-effective techniques to image the body and treat disease. It provides doctors with information about both structure and function. Nuclear medicine uses very small amounts of radioactive materials (radiopharmaceuticals) to diagnose and treat disease. Uses a 'gamma camera' to detect the radiation from the radioactive material.

Sonography (Ultrasound) - With the use of a transducer that emits high-frequency sound waves to produce relatively precise images of structures within your body.

MODALITIES: NUCLEAR MEDICINE & SONOGRAPHY

ULTRASOUND GUIDED: FINE NEEDLE ASPIRATION A type of biopsy procedure. In fine needle aspiration, a thin needle (attached to a syringe) is

inserted into an area of abnormal-appearing tissue or body fluid. It is then, the contents suctioned out and the specimen are placed on slides and/or containers and sent off to a pathologist for diagnosis.

PAPILLARY CARCINOMA – MEDULLARY CARCINOMA – FOLLICULAR CARCINOMA

ANAPLASTIC CARCINOMA – LYMPHOMA – THYROID METASTASES

REFERENCES

Mosby’s Comprehensive Review for General Sonography

Examinations – Susanna Ovel

Examination Review for Abdomen & Obstetrics and

Gynecology – Steven M. Perry

PATIENT CASES

Take from MDX patient files

PATIENT DEMOGRAPHICS

• 42 yr. old

• Female

• History of Thyroid nodule since 2009

• S/P FNAB 2009

• Latest Ultrasound study May 26,2012

• S/P FNAB March 3,2013

PATIENT DEMOGRAPHICS

• 44 yr. old

• Female

• Thyroid nodules found on the right lobe

• Latest Ultrasound study August 2012

• S/P FNAB November 2012

PATIENT DEMOGRAPHICS

• 82 yr. old

• Female

• Neck mass

• Hx thyroid cancer; papillary carcinoma

• S/P Thyroidectomy 2006 & Radiation therapy

• September 2006; palpable lump on neck Level IV

PATIENT DEMOGRAPHICS

• 39 yr. old

• Female

• Neck mass

• Hx RAI Uptake in right inferior thyroid bed

• S/P thyroidectomy 2010

• Considered for biopsy