SM156 Thyroid Nodules and Cancer Flashcards
Who gets thyroid cancer? Is it more serious when men or women get it?
Females > males, rises dramatically at puberty. More likely to be malignant when males get it
What type of thyroid cancer has increased in incidence? What’s the prognosis?
Papillary cancer
Young people (<45) almost always have a normal lifespan, older people do worse
What type of thyroid cancer do people die from the most, and why?
Papillary (50% of deaths) – it’s by far the most common
Why have thyroid cancers increased in incidence?
1) more frequent detection and 2) increased exposure to radiation (from x-rays or from bombs)
What is the first step in diagnosing a thyroid nodule?
FNA (fine needle aspiration)
Which tumor types arise from follicular thyroid cells? Which types from parafollicular cells? Which type is undifferentiated?
Follicular thyroid cells: papillary and follicular
Parafollicular cells: medullary
Undifferentiated: anaplastic (rare, very malignant)
In follicular adenomas, is the capsule intact or broken? In follicular carcinomas?
Adenomas have an intact capsule and no cellular infiltration into lymph or vasculature. Carcinomas break the capsule and invade
4 steps in treatment for thyroid cancer?
Diagnosis –> Thyroidectomy –> Ablation of residual tissue (normal and malignant with radioiodine) –> Surveillance
Why does radioiodide (131 iodine) work as a treatment for thyroid cancers?
Thyroid expresses Na/I co-transporter
Levothyroxine treatment following thyroidectomy?
Don’t give for the first 4 weeks so that TSH gets high and the cells left after surgery are primed to take up radio iodine, then give high levels for a short time after to suppress TSH and avoid thyroid cell growth
Where do thyroid cancers commonly metastasize?
Lung, bone, local lymph nodes
Papillary carcinoma: tissue of origin, prognosis, pathology?
Follicular cells
Excellent prognosis in young people
Empty-appearning nuclei (Orphan Annie’s eyes), psammoma bodies, nuclear grooves
Medullary carcinoma: origin tissue and specific cell, pathology?
Parafollicular “C” cells
Produces calcitonin, sheets of cells in amyloid stroma, associated with MEN2A and MEN2B
Follicular carcinoma: tissue of origin, prognosis, pathology?
Follicular cells
Good prognosis
Uniform follicles
What protein is disrupted in medullary cancer? What are some of the specific mutations?
RET tyrosine kinase
FMTC, MEN2A, MEN2B
