Most thyroid nodules are benign.
Order a neck ultrasound that include
the evaluation of the thyroid
and cervical lymph nodes when
concerned about thyroid nodules.
On exam, assess the texture, mobility
and for any associated lymphadenopathy.
The risk of malignancy on
thyroid nodule is increased
when a hard, fixed nodule is found
adherent to the surrounding tissue
and tends to be non mobile when swallowing.
Also, associated cervical
lymphadenopathy is a concerning sign.
Thyroid nodules can be defined
as benign or malignant.
Let go through some of the causes
of benign thyroid nodules.
Hashimoto's thyroiditis or chronic lymphocytic
thyroid nodules tend to be the most common.
But multinodular goiters or colloid
adenomas will give you thyroid nodules,
colloid cysts, cysts that have been
blend into or hemorrhagic cysts,
follicular adenomas and the very rare
Hurthle cell adenoma are examples.
Malignant causes of thyroid nodules include papillary
thyroid carcinoma which is the most common.
Followed by follicular thyroid carcinoma, medullary
thyroid carcinoma and anaplastic thyroid cancer.
Primary lymphoma of the thyroid is very
rare as all metastases but when these occur,
usually suspect melanoma, renal, colon
or breast as the primary source.
Increased risk of malignancy should be assessed
when evaluating a patient with a thyroid nodule.
If the patient has had a prior history
of radiation to the head and neck,
there is an increased chance that
the nodule may be malignant.
Also, if there is a family or
personal history of thyroid cancer,
if the patient is male versus female, if
the patient is very young or very old,
if the nodule has grown very rapidly
and then finally, if the nodule is causing
alterations in voice or hoarseness.
Let's go through a flow diagram that will
help you evaluate the thyroid nodule.
As with everything in thyroid disease,
you start with history and physical assessment
and then go on to a thyroid
stimulating hormone analysis.
If the TSH is high or normal,
perform a thyroid ultrasound.
If a nodule found on ultrasound
is greater than 1 centimeter,
refer the patient for an
ultrasound-guided fine needle aspiration
to check the pathology of the underlying
nodule and rule out malignancy.
If the thyroid nodule is less than 1 cm, repeat the
ultrasound in 6 to 24 months and follow them clinically.
If on the other hand the TSH is low, do a thyroid
scan and check your free T4 and free T3.
If the thyroid scan demonstrates
a functioning or "hot" nodule,
no FNA is generally required, just treat
their underlying hyperthyroidism.
As mentioned, toxic or active thyroid nodules
have a very, very low malignancy potential.
If on the other hand, the nodule is non
functioning or cold or on the warmer side,
evaluate these patients with an ultrasound
guided FNA as the risk of malignancy is higher.