Thyroid and Parathyroid

ASSESSMENT OF PATIENTS WITH THYROID DISEASE
Thyroid disease may be divided into two types: problems relating to function
(hyperthyroidism/hypothyroidism) and thyroid masses. The two types are not
. mutually exclusive and patients frequently present with both problems
History
Obtaining an accurate history is essential in assessing thyroid disease. Symptoms such
as dysphagia, dyspnea, and choking are frequently encountered in patients with goiter
and may be exaggerated by patients raising their arms above their heads (Pemberton's
sign). Pain is uncommon. Localized pain may suggest malignancy, especially
medullary thyroid cancer, whereas pain radiating to the ear often is observed in
patients with thyroiditis or hemorrhage within the thyroid gland. A change in the
character of the voice should also be of concern because it may suggest involvement
of the recurrent laryngeal nerves in a malignant process, with vocal cord paralysis. A
past history of exposure to radiation, family history of benign or malignant thyroid
disease, living in an iodine- deficient area, or ingestion of goitrogenic drugs also are
. significant
Physical Examination
Thyroid masses rise on swallowing; most thyroid swellings are accurately discernible
by observing the patient swallow. Failure to observe before palpating the thyroid
gland may lead to missing a large retrosternal goiter arising from beneath the sternum
. and clavicles
Palpation usually is performed from behind while the patient is sitting in a chair with
the neck slightly extended and should include palpation of the gland while the patient
swallows. A landmark is the cricoid cartilage; the isthmus almost always crosses a
fingerbreadth below the cricoid. The normal thyroid gland usually is not palpable
unless the patient has a particularly thin neck. The thyroid gland may be diffuse and
bilaterally enlarged (goiter), as encountered in conditions such as Graves' disease
(hyperthyroidism), Hashimoto's thyroiditis, or multinodular goiter. A unilateral mass
. may be palpated, as in a colloid nodule, follicular adenoma, or carcinoma
The cervical chain of lymph nodes should be assessed as well as the nodes in the
posterior triangle. The jugular nodes immediately adjacent to a thyroid nodule often
are involved in patients with a papillary thyroid cancer. A Delphian node should be
. palpated for just above the thyroid isthmus and cricoid cartilage
Fine-Needle Aspiration Cytology (FNAC
(
Fine-needle aspiration cytology is a simple and low-risk technique that is an integral
part of thyroid assessment in the outpatient setting for patients with thyroid nodules.
A 23-gauge needle is inserted into the thyroid swelling, and several passes are made
while aspirating the syringe. Cells are placed on prelabeled dry glass slides; some are
then immediately placed in 70% alcohol while others are air dried. These slides are
stained by Papanicolaou or Wright's stains and observed under the microscope.
Skilled cytopathologists can accurately diagnose the majority of thyroid diseases
using this technique, with a high degree of specificity. This test is less accurate in
patients with thyroid nodules and a history of familial nonmedullary thyroid cancer
and in patients with a previous history of exposure to low-dose therapeutic radiation.