10/9- Pathology of the Thyroid Flashcards
What is this?
Thyroid!
What is seen here?
Follicular cells- originate from endoderm, from foramen cecum
Colloid-
What is seen here?
C cells
- Brown-staining marks calcitonin-producing cells
- Arise from ?
What is Ultrasound Guided FNAB?
Fine Needle Aspiration Biopsy
- Really cut down on amount of thyroidectomies that were performed
- Before FNA, only indication for thyroidectomy was existence of a cold nodule (many benign taken out)
What is seen here?
Left: histological section
Right: cells from FNA
- Round, regular nuclei
- Cytoplasm fits together in honeycomb pattern; not much overlap
- Very benign thyroid
Causes of hypothyroidism?
- Hashimoto thyroiditis (most common cause)
- Surgical or radioactive isotope ablation
Causes of hyperthyroidism?
- Diffuse Toxic Hyperplasia (Grave’s Disease)
- Typically in younger women
- Toxic Nodule in Multinodular Goiter (Plummer syndrome)
- Typically in older women
- Toxic adenoma
- Metastatic Follicular Carcinoma of thyroid
- Excess exogenous thyroid hormone
Epidemiology of Hashimoto thyroiditis
- # __ cause of hypothyroidism in iodine ____ regions
- Demographic
- # __ autoimmune endocrine disease
- May result in what
- Characteristic features
- #1 cause of hypothyroidism in iodine sufficient regions
- Young-middle aged women
- #1 autoimmune endocrine disease
- May result in asymmetric enlargement and be confused with a neoplasm
- Lymphoid follicles, oncocytic metaplasia of follicular cells (Hurthle cells)
What is seen here?
Gross features of Hashimoto’s thyroiditis
- More tan/tank-pink than normal (not as red)
- Thyroid parenchyma infiltrated by lymphoid cells
What is seen here?
Hashimoto’s thyroiditis
- Asymmetrical
- Very intense thyroiditis (possibly also neoplasm)
What is seen here?
Hashimoto’s thyroiditis
- Can see thyroid follicle with germinal center
- Follicular cells show abnormal excess of eosinophilic cytoplasm
What is seen here?
Typical Hashimoto’s thyroiditis
- Lymphoid cells crawling over normal follicular cells
- Follicular epithelium slightly abnormal: pale nuclei
What is seen here?
Islands of atypical cells as the result of inflammation
- Hyperchromasia
- Nuclear grooves
Characteristics of Subacute Thyroiditis (Granulomatous, DeQuervain)
- Prognosis
- Gender prevalence
- Cause
- Course
- Features
- Self limited, frequently after URI
- Female 3-5x more affected
- Fever and tender/painful enlargement of thyroid
- Course of 6-8 weeks, with hyperthyroidism to hypothyroidism to normal
- Multinucleated giant cells and acute inflammation with destruction of follicles
What is seen here?
Subacute Thyroiditis (Granulomatous, DeQuervain)
- Intense area of thyroiditis
- Makes clinical nodule
What is seen here?
Subacute Thyroiditis (Granulomatous, DeQuervain)
- Destruction of follicle?
What is seen here?
Subacute Thyroiditis (Granulomatous, DeQuervain)
- Follicle is being destroyed
- Colloid leaks directly into bloodstream, leading to initial hyperthyroidism
- After a time, depletion causes hypothyroidism
What is seen here?
Subacute Thyroiditis (Granulomatous, DeQuervain)
- Multinucleated giant cells
- Colloid on left
What is seen here?
Subacute Thyroiditis (Granulomatous, DeQuervain)
- Multinucleated giant cells
What is Reidel Thyroiditis?
- Prevalence
- Pathology
- Similar to what
- Very rare
- Dense fibrosis replacement of thyroid gland with extension into adjacent tissue
- Simulates carcinoma clinically
What is seen here?
Reidel Thyroiditis
- Dense lymphocytic infiltrate
- Large ropey collagen bands between infiltrate
- Few scattered follicles
What is seen here?
Reidel Thyroiditis
- Few scattered follicles
- Dense collagen bundles
What is seen here?
Reidel Thyroiditis
- Dense fibrosis growing out into adjacent strap muscles around thyroid
Characteristics of Graves Disease
- Demographic
- Symptoms
- Lab findings
- Mechanism
- Aka diffuse toxic goiter
- 1-2 % of women (females 7x more)
- Exophthalmos common
- Autoantibodies activate TSH receptor
- Increase in size of gland with hyperplasia of the follicular cells
What is seen here?
Graves?
What is seen here?
Graves
- Follicles no longer round
- Hyperplastic cells; pile up within follicles
What is seen here?
Normal thyroid
- Cells relatively quiescent
What is seen here?
Graves Disease
- Nuclei open
- Actively synthesizing protein
- Very active cells
What is seen here?
Radioactive scan of thyroid in Grave’s disease
- Diffuse concentration
What is a multinodular goiter?
- Etiology
- Similar to
- Symptoms
- Transformation
- Much more in women
- Etiology other than iodine deficiency unclear
- Most common mimic of thyroid neoplasia clinically
- May produce extreme enlargement
- Component nodule is “adenomatous” or hyperplastic nodule
- Multiple ill defined nodules with colloid lakes (colloid nodules)
- An individual nodule may become toxic (Plummer’s syndrome) later in life
What is seen here?
Multinodular goiter
- Typically asymmetrical
What is seen here?
Multinodular goiter- cut section (Benign adenomatous nodule)
- Colloid lakes (areas of degeneration)
- Not well capsulated; ill-defined
- Vague hyperplastic nodules replace thyroid parenchyma
What is seen here?
Multinodular goiter
- Large follicles (100x normal)
- Lots of colloid
- Cells lining the follicles look normal
What is seen here?
Multinodular goiter
- Hemosiderin lake of macrophages from area of old hemorrhage
What is seen here?
Multinodular goiter
- Bland clusters of ?
- Much background colloid
What is seen here?
Adenomatous nodule that underwent cystic degeneration
- Nodule itself has internal septi
- Some adenomatous nodule remaining on rim
- Remnant could be targeted with US
- Vast majority of cystic nodules like this are adenomatous with cystic degeneration (rarely cystic papillary adenoma)
What is seen here?
Scan of pt with Plummer syndrome
- Can see some nodularity with hyperfunctioning that is suppressing much of the rest of the gland function
- Autonomously functioning thyroid nodule arising from multinodular goiter
Most tumors of thyroid derive from what?
Follicular epithelium
- Can be adenoma or carcinoma
- Nodules are typically composed of discrete thyroid follicles (small or normal sized)
- Well defined capsule
- Surrounding thyroid is relatively normal
What is seen here?
Thyroid adenoma
- White discrete fibrous capsule; well-defined
- Normal surrounding thyroid
Which is more common: follicular adenoma or carcinoma?
Adenoma is 10x more common than carcinoma (?)
What is seen here?
- Fibrous capsule
- Benign neoplasm forming small micro-follicles
What is seen here?
Follicular carcinoma
- Tumor on the bottom
- Compressed normal thyroid adjacent
- Carcinoma breaking through dense fibrous capsule into surrounding gland (capuslar invasion)
What is seen here?
Follicular carcinoma: vascular invasion?
Papillary cancer typically metastasizes where? Follicular?
Papillary -> local LNs
Follicular -> bones
What is seen here?
Papillary cancer
- Not well encapsulated
- Irregular border
- Invasive
- Fibrous look
What is seen here?
Papillary cancer
- Clear nuclei; characteristic of this type of cancer!!
What is seen here?
Medullary carcinoma
- Cancer of C cell (calictonin producing cell)
What is seen here?
Medullary carcinoma
- Relatively small cells
- Not forming follicles or papilla
- Background pink amyloid (beta-pleated sheet pattern) due to hormones (Calcitonin)
What is seen here?
Ultrastructural analysis of medullary carcinoma
- Dense core neurosecretory granules; characteristic of tumors that drive neuroectoderm
What is seen here?
Anaplastic carcinoma
- Rare; 1-2% of thyroid cancers
- Poor prognosis; essentially incurable
- Older individuals
What is seen here?
Anaplastic carcinoma
- Tumor encased espohagus/epiglottis area
What is seen here?
Low grade papillary carcinoma
- Developed rapidly growing cancer within this (on the right)
- Cells on the right are much more anaplastic (huge nucleolus, many mitotic figures)…
Embryologic development of the thyroid?
- Derives from foramen cecum, midline base of tongue (not degraded by GIT; can take orally)
- Descends in the midline neck, may result in lingual throid, thryoglossal duct cyst or pyramidal lobe
What are the main cell types of the thyroid? Origin?
- Follicular cells (endoderm)
- C-cells (neural crest)
What is seen here?
Thyroglossal duct cyst
- Cells lining cystic space proliferate, die, produce necrotic material that accumulates in this cystic space -> enlargement
Parathyroid glands originate from what embryological structure(s)
3rd and 4th pharyngeal pouch
How many parathyroids are there?
Typically 4
What is seen here?
Adipose tissue and chief cells, oxolytic cells, etc. all in parathyroid gland
What are causes of primary hyperparathyroidism?
- Parathyroid adenoma (85%)
- More common in women (40s/50s)
- Parathryoid hyperplasia (15%)
- Parathryoid carcinoma (under 1%)
What are some causes of hypercalcemia?
Malignancy
- Osteolytic metastases
- PTH-like hormone production
Hyperparathyroidism
Other
What is seen here?
Parathyroid adenoma
What is seen here?
Parathyroid adenoma
- Diffuse population of relatively benign appearing cells (just too many of them)
What is seen here?
Parathyroid carcinoma
What is seen here?
Parathyroid carcinoma
- Cells don’t look benign
- Nuclear irregularity
What is seen here?
Parathyroid adenoma
What is seen here?
Parathyroid carcinoma
