Pathology of the Thyroid II Flashcards
goiter
enlargement of thyroid
impaired synthesis of thyroid hormon
most often - dietary iodine deficiency
diffuse nontoxic goiter
simple**
enlargement of entire gland without nodularity
endemic goiter
areas with low iodine
can lead to diffuse nontoxic simple goiter
sporadic goiter
less frequent than endemic
-more in female around puberty or young adult life
increased TSH levels
lead to hypertrophy and hyperplasia of thyroid follicular cells
with simple goiter
phases of nontoxic goiter formation
hyperplastic phase
-diffuse and symmetric enlargement
colloid involution
-if increased dietary iodine or demand for thyroid hormone decreases - stimulated follicular epithelium involutes - resulting in enlarged colloid rich gland
simple goiter clinical
typically euthyroid
clinical problems - mass effects
normal T3 and T4 with elevated TSH
multinodular goiter
over time - recurrent episodes of hyperplasia and involution
irregular enlargement of thyroid
often mistaken for neoplasms
female with tickle in throat, solid lesion near thyroid
multinodular goiter
but need to see if is neoplasm
male - more likely to be noeplastic
plunging goiter
multinodular goiter growing behind sternum and clavicles
multinodular goiter morph
asymmetrically enalrged
colloid rich follicles lined by flattened inactive epithelium and areas of follicular hyperplasia
follicular neoplasm of thyroid
prominent capsule between hyperplastic nodule and residual compressed thyroid parenchyma
multinodular goiter clinical
often see mass effects
airway obstruction, dysphagia, superior vena cava syndrome**
most patients euthyroid
small number of patients - toxic multinodular goiter (hyperthyroidism)
plummer syndrome
toxic multinodular goiter
has NO dermopathy or ophthalmopathy - as in graves
uneven iodine uptake
solitary thyroid nodule
dominant nodule in multinodular goiter
can mimic a thyroid noeplasm
solitary thyroid nodule
more common in women
majority are localized and non-neoplastic
benign neoplasms outnumber thyroid carcinomas 10:1
clinical criteria for thyroid nodule
solitary - more likely neoplastic
younger patient - more likely neoplastic
males - more likely neoplastic
radiation history - more likely thyroid malignancy
functional - take up radioiodine - hot nodule - tend to be benign
52yo M, lump in neck, solitary thyroid nodule, TSH and T4 normal
cold nodule radioiodine
fusion scan shows vascularity
male, solitary, cold nodule - worried about neoplasm
fusion scan
shows vasculature
follicular adenoma
adenoma of thyroid
discrete solitary mass derived from epithelium
toxic adenoma
produce thyroid hormone
independent of TSH stimulation
solitary spherical lesion in thyroid with capsule
thyroid adenoma
multinodular goiter - no capsule
follicular adenoma vs. carcinoma
evaluation for invasion of capsule is critical**
hurthle cell change
implies aggressiveness
cold nodule
does not take up radioiodine
-10% are malignant**
need to evaluate capsular integrity
majority of thyroid carcinoma
papillary carcinoma
85% of cases
5-15% follicular
5% anaplastic
5% medullary
papillary carcinoma of thyroid
good prognosis
follicular carcinoma of thyroid
worse prognosis
most common form of thyroid carcinoma
papillary carcinoma
white tumor of thyroid
papillary carcinoma
optically clear nuclei
in papillary carcinoma of thyroid
good prognosis
orphan annie eye nuclei
optically clear nuclei
papillary carcinoma
lymph node mets in papillary carcinoma
still good prognosis**
35yo cuts neck shaving, feels lump in neck
surgeon removes metastatic papillary carcinoma
prognosis?
good**
mets don’t change prognosis
papillary thyroid carcinoma - has excellent prognosis - 10 yr survival 95%
hemorrhagic red lesion in thyroid
follicular carcinoma
follicular carcinoma
areas with dietary iodine deficiency
women age 40-60yo
spread is hematogenous - to lung and bone
scintigram
radioactive tracer distribution in organ
follicular carcinoma
often cold nodule
-may be warm
hematogenous spread common - mets to bone, lung, and liver
prognosis of follicular carcinoma of thyroid
widely invasive - systemic mets - bad
minimally invasive - not as bad - 10yr survival 90%
monitor recurrence of follicular thyroid carcinoma
thyroglobulin levels
mutations of RAS or PI-3K/AKT pathways
follicular carcinomas
anaplastic carcinoma of thyroid
undifferentiated
- less than 5%
- bad prognosis - 100% mortality
age 65yo
1/4 patients have history of well-differentiated thyroid carcinoma
pleomorphic giant cells and spindle cells
anaplastic carcinoma of thyroid
rapidly enlarging neck mass, dyspnea, dysphagia, hoarseness, cough
anaplastic carcinoma of thyroid
death less than 1 year
medullary carcinoma of thyroid
neuroendocrine neoplasm of parafollicular C cells**
C cells
secrete calcitonin from thyroid
cells in medullary carcinoma
diagnosis of medullary carcinoma of thyroid
calcitonin levels
also important for post-op follow up
medullary carcinoma
70% arise sporadically
remainder from MEN 2a and 2b or FMTC
bilateral and multicentric medullary carcinoma
familial cases
amyloid
in medullary carcinoma of thyroid
carcinoembryonic antigen
biomarker for medullary carcinoma
useful in presurgical tumor assessment of tumor load and calcitonin negative tumors
more aggressive medullary carcinomas
context of MEN-2B
more frequent mets and more aggressive
RET mutation
offered prophylactic thyroidectomy
asymptomatic MEN-2 patients
because 100% get medullary carcinoma of thyroid
