PANCE Blueprint Endocrinology (6%)

Patient will present as → a 45-year-old female presents to the clinic with a complaint of a painless lump in her neck that she noticed two months ago during routine grooming. She denies any associated pain, difficulty swallowing, voice changes, or breathing difficulties. She has no family history of thyroid disease or cancer. On physical examination, a 1.5 cm, firm, non-tender nodule is palpated in the left lobe of the thyroid. There is no cervical lymphadenopathy, and the rest of the thyroid gland is normal. Thyroid function tests reveal a normal TSH level. Ultrasound of the thyroid shows a well-circumscribed, isoechoic nodule with no suspicious features. A fine-needle aspiration (FNA) biopsy is performed and cytology reveals findings consistent with a benign colloid nodule. She is reassured about the benign nature of the nodule and counseled that no further immediate intervention is needed. Regular monitoring with annual thyroid ultrasound is recommended to assess for changes in size or characteristics. The patient is advised to return if she develops symptoms such as pain, rapid growth of the nodule, or compressive symptoms. Thyroid function tests will be rechecked periodically to ensure ongoing euthyroid status.

The most common risk factor for thyroid carcinoma is radiation exposure

• Most common in young females 40-60 years old
• You may (not always) feel a palpable thyroid nodule/mass

There are 4 general types of thyroid cancer:

• Papillary carcinoma (80%) is the most common. Remember: PAPILLARY IS POPULAR
• Follicular: (10%) is more common among older patients and in regions of iodine deficiency. It is more malignant than papillary carcinoma, spreading hematogenously with distant metastases
• Medullary: (4%) may be sporadic (usually unilateral); often familial
• Anaplastic: (1%) No effective therapy exists, and the disease is generally fatal. About 80% of patients die within 1 year of diagnosis

Except for anaplastic and metastatic medullary carcinoma, most thyroid cancers are not highly malignant and are seldom fatal

• Most thyroid cancers manifest as asymptomatic nodules. Rarely, lymph node, lung, or bone metastases cause the presenting symptoms of small thyroid cancers

Solitary thyroid nodule: 

• A solitary thyroid nodule is common in the general population and affects women more often than men. One in 12 young women has a thyroid nodule
• Nodules must generally be over 1 cm in diameter to be palpated. Most are asymptomatic and are discovered incidentally via physical exam or through imaging. The presence of one palpable nodule increases the risk of additional nodules
• Thyroid adenoma is the most common benign nodule. Only 5% of palpable nodules are malignant

If you think you have a mass, you will need to confirm by ultrasound

• Lesions larger than 1 cm should be biopsied
• Smaller lesions and those with benign histology can be followed and reevaluated if they grow

Ultrasound characteristics that put a nodule at high risk of malignancy are:

• Microcalcifications, hypoechogenicity, a solid nodule, irregular nodule margins, chaotic intranodular vasculature, and a nodule that is more tall than wide. 

You must identify if the mass is benign or malignant. To do this, you can order a thyroid uptake scan

• A cancerous lesion does not make hormones and will not take up iodine from a radioactive thyroid scan. (COLD NODULE)
• A non-cancerous lesion does make hormones and will take up iodine at either a normal rate or a quicker rate. (HOT NODULE)

Remember: COLD = CANCER

Once you see a cold nodule, you must rule out cancer. To do this, you will need a FINE NEEDLE ASPIRATION

Papillary thyroid carcinoma on CT, PET CT, and ultrasonography

Treatment depends on the type of cancer, and prognosis depends on staging, with a 99% 5-year survival with locally confined, less than 1 cm papillary carcinoma

• Always involves complete or partial removal of the thyroid with chemotherapy and external beam radiation reserved for anaplastic thyroid cancer

Evaluation of a thyroid nodule

Suggested diagnostic and treatment approach for thyroid nodules (AAFP) Click Here