Papillary Thyroid Cancer

WHAT IS IT? 

Papillary thyroid cancer refers to a neoplastic growth within the thyroid (typically a carcinoma of epithelial cell origin: thyroid follicular cells). Causes are either genetic or sporadic mutations in various genes (such as the RET/PTC chimeric gene).

WHY IS IT A PROBLEM?

Mutations in genes (such as RET and BRAF) lead to oncogenesis leading to excessive growth of thyroid epithelial cells (carcinoma). Patients are often asymptomatic given the indolent nature of most of these tumors.

WHAT MAKES US SUSPECT IT?

Risk factors: RET and BRAF mutations, exposure to irradiation, family history

Palpable thyroid nodule is possible on physical examination.  Pain/difficulty swallowing can also sometimes be observed.

Non-palapble thyroid nodule on routine imaging can also be observed.

Papillary thyroid cancer nodule seen on axial CT scan (source)
Papillary thyroid cancer nodule seen on axial CT scan (source)
HOW DO WE CONFIRM A DIAGNOSIS?

Measure TSH in the serum.

  • If low conduct radionuclide scan
  • If high/normal conduct ultrasound

Thyroid (radionuclide scanning): will characterize if the nodule is either hypo/hyperfunctioning.

Radionuclide imaging can reveal the presence of both "hot" and "cold" nodules in papillary thyroid cancer (source)
Radionuclide imaging can reveal the presence of both “hot” and “cold” nodules in papillary thyroid cancer (source)

Perform thyroid ultrasound in order to confirm possible node finings on physical exam.

Ultrasound of a patient with a papillary thyroid cancer nodule (source)
Ultrasound of a patient with a papillary thyroid cancer nodule (source)

Fine needle aspiration (FNA) biopsy can reveal the presence of lymphocytic infiltrate, papillae of tumor cell layers,absence of follicles/colloid and….

Empty appearing nuclei with central clearings (these are called “Orphan Annie” eyes).

"Orphan Annie" nuclei seen in a biopsy of a patient with papillary thyroid cancer (source)
“Orphan Annie” nuclei seen in a biopsy of a patient with papillary thyroid cancer (source)

Psammoma bodies which are round collections of calcium.

Appearance of psammoma body in a case of papillary thyroid cancer (source)
Appearance of psammoma body in a case of papillary thyroid cancer (source)
HOW DO WE RULE OTHER DIAGNOSES OUT?

The biopsy will be useful in characterizing the type of thyroid cancer that is present.

HOW DO WE TREAT IT? 

Thyroidectomy refers to the surgical removal of the thyroid gland which is an option for thyroid cancers (can be total or partial)

Postoperative radioiodine ablation can be used to destroy residual thyroid tissue. Iodine-131 is used for this purpose.

HOW WELL DO THE PATIENTS DO?

This type of thyroid cancer has an excellent prognosis (best prognosis out of the different types of thyroid cancer) with a very high rate of survival.

WAS THERE A WAY TO PREVENT IT?

Ionizing radiation (nuclear reactor accidents/radiotherapy) has been linked to papillary thyroid cancer occurrence, and limiting childhood exposure to radiation might reduce papillary thyroid cancer risk.

WHAT ELSE ARE WE WORRIED ABOUT? 

Metastasis can occur via the lymphatics.

Hypocalcemia can occur in patients who have their parathyroid hormones removed during a thyroidectomy.

Voice hoarseness can be caused by damage to the recurrent laryngeal nerve during thyroid surgery.

OTHER HY FACTS?

This is the most common type of thyroid cancer

FURTHER READING

DynaMed

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Page Updated: 02.21.2016