Thyroid Pathology Flashcards
Hashimoto Thyroiditis
Lymphoid tissue with Germinal Centers
Hurthle Cell
Hashimoto Thyroiditis
Subacute thyroiditis (deQuervain)
Supprurative (neutrophils)
Subacute Thyroiditis (de Quervain)
Granulomatous (giant cells)
Fibrous (Riedel) Thyroiditis
Graves’ Disease
Irregular follicles
Scallopped colloid
Histology of Goiter
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)
Thyroid Nodular Hyperplasia
Nodular Hyperplasia
Solitary palpable thyroid nodules
4x more common in women
Majority are non-neoplastic (focal hyperplasia, simple cysts) or benign (adenomas)
Carcinoma is relatively uncommon
What is used to test indeterminant or uncertain nodules?
Characteristics of Follicular Adenoma
Solitary
Completely surrounded by fibrous capsule
No capsular invasion or vascular invasion
Different growth pattern from adjacent normal gland
Follicular Adenoma
Follicular Adenoma - Variable appearances
Thyroid Carcinoma
Uncommon
Mortality is low
More common in women
All ages
Risk factor = exposure to ionizing radiation
Types of Thyroid Cancer
Papillary (85-95%)
Follicular
Medullary
Anaplastic
Lymphomas
Sarcomas
Mutation in Follicular thyroid cancer
RAS oncogene
t(2;3)
PAX8-PPARgamma1 fusion gene
Mutation in Papillary thyroid cancer
BRAF oncogene - inv(10)
RAS - t(10;17)
ret/PTC fusion gene
Medullary Thyroid Cancer Mutation
RET (germ-line)
Anaplastic Thyroid Cancer mutation
P53 tumor suppressor
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
Papillary thryoid Cancer
Papillary Carcinoma
Gross
Papillary Carcinoma Diagnosis
Papillary architectures
Chewing gum colloid
Multinucleated giant cells
Papillary Carcinoma
Nuclear Features
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
Follicular Thyroid Carcinoma
Criteria for diagnosis of Follicular Carcinoma
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
Follicular Carcinoma
Capsular invasion
Follicular Carcinoma
Vascular invasion
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
Medullary Carcinoma
Medullary Carcinoma
Nests of neuroendocrine cells
Medullary carcinoma
Amyloid stroma
Medullary Carcinoma
Calcitonin stain
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
Anaplastic carcinoma
Anaplastic carcinoma
Spindle cell type
Anaplastic carcinoma
Epitheliod type
