Thyroid Pathology

Question 1

Answer 1

Hashimoto Thyroiditis

Lymphoid tissue with Germinal Centers

Question 2

Answer 2

Hurthle Cell

Hashimoto Thyroiditis

Question 3

Answer 3

Subacute thyroiditis (deQuervain)

Supprurative (neutrophils)

Question 4

Answer 4

Subacute Thyroiditis (de Quervain)

Granulomatous (giant cells)

Question 5

Answer 5

Fibrous (Riedel) Thyroiditis

Question 6

Answer 6

Graves’ Disease

Irregular follicles

Scallopped colloid

Question 7

Histology of Goiter

Answer 7

Follicles lined by croweded columnar cells

Variably sized follicles

Abundant colloid

Initial stages result in symmetrical, diffuse enlargement

Recurrent episodes lead to a multinodular gland

With time develop degenerative changes (cysts, fibrosis, calcification, hemorrhage)

Question 8

Answer 8

Thyroid Nodular Hyperplasia

Question 9

Answer 9

Nodular Hyperplasia

Question 10

Solitary palpable thyroid nodules

Answer 10

4x more common in women

Majority are non-neoplastic (focal hyperplasia, simple cysts) or benign (adenomas)

Carcinoma is relatively uncommon

Question 11

What is used to test indeterminant or uncertain nodules?

Question 12

Characteristics of Follicular Adenoma

Answer 12

Solitary

Completely surrounded by fibrous capsule

No capsular invasion or vascular invasion

Different growth pattern from adjacent normal gland

Question 13

Answer 13

Follicular Adenoma

Question 14

Answer 14

Follicular Adenoma - Variable appearances

Question 15

Thyroid Carcinoma

Answer 15

Uncommon

Mortality is low

More common in women

All ages

Risk factor = exposure to ionizing radiation

Question 16

Types of Thyroid Cancer

Answer 16

Papillary (85-95%)

Follicular

Medullary

Anaplastic

Lymphomas

Sarcomas

Question 17

Mutation in Follicular thyroid cancer

Answer 17

RAS oncogene

t(2;3)

PAX8-PPARgamma1 fusion gene

Question 18

Mutation in Papillary thyroid cancer

Answer 18

BRAF oncogene - inv(10)

RAS - t(10;17)

ret/PTC fusion gene

Question 19

Medullary Thyroid Cancer Mutation

Answer 19

RET (germ-line)

Question 20

Anaplastic Thyroid Cancer mutation

Answer 20

P53 tumor suppressor

Question 21

Most common form of thyroid cancer

Younger age group (20s-40s)

Metastasize by lymphatics

Cervical nodes involved in up to 50%

Excellent prognosis (>95% 20 year survival)

Adverse prognostic factors include: age >40, tumor >5cm, extrathyroidal extension adn osseous metastasis

Answer 21

Papillary thryoid Cancer

Question 22

Answer 22

Papillary Carcinoma

Gross

Question 23

Answer 23

Papillary Carcinoma Diagnosis

Papillary architectures

Chewing gum colloid

Multinucleated giant cells

Question 24

Answer 24

Papillary Carcinoma

Nuclear Features

Question 25

Second most common thyroid cancer Presents older age (40s-50s) Slowly spreading painless nodule Vascular spread to bones, lungs, liver etc Prognosis depends on stage at presentation

Answer 25

Follicular Thyroid Carcinoma

Question 26

Criteria for diagnosis of Follicular Carcinoma

Answer 26

No cytological features of malignancy Most tumors well-differentiated Capsular invasion Vascular invasion Minimally invasive carcinomas are difficult to distinguish from follicular adenomas and extensive sampling of the capsule is required

Question 27

Answer 27

Follicular Carcinoma Capsular invasion

Question 28

Answer 28

Follicular Carcinoma Vascular invasion

Question 29

Neuroendocrine tumors derived from the parafollicular (C-cells) of the thyroid Secrete calcitonin 80% sporadic 20% within families as part of MEN-2 Syndrome Incidence in 40s and 50s (except with MEN-2 in childhood) 40-60% survival at 10 years

Answer 29

Medullary Carcinoma

Question 30

Answer 30

Medullary Carcinoma Nests of neuroendocrine cells

Question 31

Answer 31

Medullary carcinoma Amyloid stroma

Question 32

Answer 32

Medullary Carcinoma Calcitonin stain

Question 33

Undifferentiated tumors of follicular epithelium Mean age is 65 years May have history of long-standing goiter, differentiated thyroid carcinoma or concurrent papillary carcinoma Extrathyroidal spread at presentation --\> hoarseness and neck pain Mean survival is 6 months

Answer 33

Anaplastic carcinoma

Question 34

Answer 34

Anaplastic carcinoma Spindle cell type

Question 35

Answer 35

Anaplastic carcinoma Epitheliod type