What is a Thyroglossal Duct cyst?
What is the differential diagnosis for those?
Vestigial remnants from thyroid migration the become cystic
can occur at any age and occurs anywhere in midline neck - anterior to trachea
See Squamous or Thyroid follicular lining cells w/ limphoid infiltrate
DDX: Squamous cell carcinoma or Branchial cleft cyst (typically more lateral)
What does Iodine Deficiency cause?
Diffuse non-toxic goiter
The best way to biopsy a thyroid nodule is FNA. But the best way to know if carcinoma vs adenoma is w/ capsular and vascular invasion which you can't see on FNA. How do we reconicile this? How can architecture help?
use cellular : colloid ratio!
Benign - Lots of colloid and less cellularity
AUS - middle
Suspicious for Follicular Neoplasm - more cellularity vs colloid
Also Architecture can help - Macrofollicles more favor benign and Micro Follicles, trabeculae and nests favor malignant
In General, what are features of benign follicular lesions?
Abundant colloid and low cellularity
Corresponds to Hyperplastic Nodules and Adenomas
<1% risk of malignancy
In general, what are features of Suspicious follicular neosplasms?
Scant/absent colloid, marked cellularity, predominantly microfollicular / solid/ trabecular architecture
corresonds to follicular adenoma, carcinoma etc
Hemithyroidectomy apropriate bc risk of malignancy is 20-30%
In general, what are features of AUS? What do you do when you see that?
Mixed features and can indicate either limited cellularity or compromised specimen
Risk of malignancy 5-10%
Repeat FNA often helpful 3-6 months - can typically wait bc more indolent tumors
What do you see grossly and histologically in Grave's Disease? What else has similar histology?
Gross: Diffusely enlarged, thyroid, homogenous, no nodules
Micro: Crowded follicular cells, papillary ingrowths (hyperplastic), pale colloid w/ scalloped border and lymphoid infiltrate w/ germinal centers
(similar histo to diffuse non-toxic goiter from iodine deficiency)
What is Hashimoot's? Who gets it? What does it make you at risk for?
Most common cause of hypothyroidism; females?males, ages 45-65
Autooimmune destruction of Thyroid w/ TPO and TGB antibodies
*Increased risk of lymphoma and papillary thyroid carcinoma
What do you see grossly and microscopically in Hashimotos?
Gross - Enlarged, firm gland that is vaguely nodular/lobular
Micro - lymphoid/PLasma cell infiltrate w/ Germinal Center formation, Follicular cell destruction
*Oncocytic / Hurthle Cell change: abudnant pink granular cytoplasms (eosinophilic)
What is Granulomatous Thyroiditis? Other names for it? What happens there/ Presentation?
AKA Subacute Thyroiditis or DeQuervain's Thyroiditis
May be secondary to viral infection
THYROID PAIN + HYPERTHYROID!!!!
resolves spontaneously in 2-6 weeks
What do yo usee grossly and micro in Thyroiditis?
Gross - enlarged, firm gland and involved areas a firm, yellow-white
Micro - patchy distribution, early neutrophils and then later Giant cells that are eating colloid and lymphoid aggregates / macrophages, eventually fibrosis
What's happening in Multinodular Goiter? Clinical Significance? What do you see grossly and microscopically?
Euthyroid presentation (sometimes hyperthyroid)
Clinical significance from size can lead to airway obstruction, dysphagia, or cosmetic complaints
Gross - multinodular and large, nodules range from soft, gelatinous and brown --> Firm and tan
(more colloid then softer and better)
Micro - normal appearing follicular cells, NO CAPSULE around nodules
What is the most common neoplasm of the thyroid? What is the most common malignancy of they tyroid ?
Neoplasm - follicular adenoma
Malignancy - papillary carcinoma
What do you see in a follicular adenoma?
Solitary nodule, usually non-fuctioning, benign course
Gross - spherical, encapsulated and sharply demarcated
- Hemorrhage, Fibrosis, CAlcifications
Colloid rich = tan-brown and gelly
Cellular = white-tan, firm
Micro - follicular cells and follicles, well-defined capsule and tumor within
Can see Hurthe cell changes!
Follicular Carcinoma different bc invasion!!
Who is more likely to get Follicular Carcinoma? How does it invade? differences from papillary? Treatment?
Older people more likely to get follicular carcinoma (Older than papillary) and Female > Male
Minimal invasion = vascular or capsular only and good prognoiss
Wide invasion = into surrounding tissue and distant Mets at presentation
HEMATOGENOUS spread to bone, lung, liver (vs papillary which is LN spread)
See Microfollicles, similar to adenoma, and Hurthle cell changes
Tx = thyroidectomy and radioactive Iodine therapy
Papillary Carcinoma - who gets it? How does it spread? Adverse prognostic indiactors?
Most common thyroid carcinoma that people can get at ANY age 25-50 yo (slightly younger than follicular)
Presents as indolent nodules or LN mets
GOOD PROGNOSIS - BEST ONE TO GET
Lymphatic Metastasis (cervical LN but does NOT worsen prognosis)
Adverse prognostic indicators:
- age > 40
- Extrathyroid extension
- mets beyond neck
What do you see gross/histo in Papillary carcinoma? What are subtypes?
Poorly defined margines and more fibrus thna adenoma
Papillary Fronds and Psammoma bodies
Pale, finely granular chromatin - Orphan Annie Eyes
Follicular variant - looks like follicular architecture but better prognosis
Microcarcinoma - < 1cm and does not metastasize
What is anaplastic Carcinoma? How does it present? DDX?
Highly aggressive malignancy and will die within 1 year
Mean age 65 - rapidly enlarging mass and HOARSENESS presentation
Arise from well-differentiated carcinoma
DDX is mets or primary SCC
Gross - large mass invading beyong thyroid
Micro- anaplastic, Spindlied (sarcomatoid) cells, Giant cells, Atypia, Necrosis
What is the Calcitonin carcinoma eh? What is the familial syndrome that causes this 30% of the time?
Can measure calcitonin in blood but no hypocalcemia
Medullary carcinoma - presentation, cells, micro/gross, etc
What's the most interesting and indicattive thing that you see in these tumors?!?!?!?!!
Presents as mass w/ paraneoplastic syndromes from ACTH or VIP production. Can mimic other thyroid tymors in terms of looks (ex. Papillary w/ Pseudopap archi and Intranuclear pseudoinclusions OR Hurhtle cell neosplasms w/ eosinophilic cyto)
NEUROENDOCRINE - SEcretes CALCITONIN
Gross - firm, tan-gray, infiltrative
Micro- plasmacytoid or spindled cells
can also see bi or multi-nucleation
How does lymphoma arise in the thyroid? What types of lymphoma do you see?
most arise in setting of Hashimoto thyroiditis
MALT - small mature B cells
- Diffuse LArge B cell Lymphoma