THYROID CANCER - PAPILLARY CARCINOMA BY: DR.FARIS MOHSIN AL-ABEEDI
Papillary carcinoma is a relativelycommon well-differentiated thyroidcancer. Papillary/follicular carcinomamust be considered a variant ofpapillary thyroid carcinoma (mixedform). Despite its well-differentiatedcharacteristics, papillary carcinomamay be overtly or minimally invasive.In fact, these tumors may spreadeasily to other organs. Papillarytumors have a propensity to invadelymphatics but are less likely toinvade blood vessels. Papillarycarcinoma appears as an irregularsolid or cystic mass in a normal
CHARACTERISTICS OF PAPILLARY THYROIDCANCER*Peak onset ages are 30 to 50 years old.*Papillary thyroid cancer is more common in females than in malesby a 3:1 ratio.*The prognosis directly related to tumor size. (Less than 1.5 cm[1/2 inch] is a good prognosis.)*This cancer accounts for 85% of thyroid cancers due to radiationexposure.*In more than 50% of cases, it spreads to lymph nodes of the neck.*Distant spread (to lungs or bones) is uncommon.The overall cure rate is very high (near 100% for small lesions inyoung patients).
CAUSESAbout 80% of all thyroid cancers diagnosed in the United States arepapillary carcinoma type. It is more common in women than inmen. It may occur in childhood, but is most often seen in adultsaround theage of 45.The cause of this cancer is unknown. A genetic defect may beinvolved.Radiation increases the risk of developing thyroid cancer. Exposuremay occur from:*High-dose external radiation treatments to the neck, especiallyduring childhood, used to treat childhood cancer or some benignchildhood conditions.*Radiation due to atomic bomb testing in the Marshall Islands and the1986 Chernobyl nuclear disaster in the Ukraine, mostly in children.*Radiation given through a vein (through an IV) during medical testsand treatments does not increase the risk of developing thyroid
EXAMS AND TESTSIf you have a lump on your thyroid, your doctorwill order blood tests and possiblyan ultrasound of the thyroid gland, CT scanIf the ultrasound shows that the lump is biggerthan 1.0 centimeter, a special biopsy calleda fine needle aspiration (FNA) will be performed.This test helps determines if the lump iscancerous.Thyroid function tests are usually normal inpatients with thyroid cancer.
This CT scan shows a thyroid cancer tumor in thethroat, encircling, narrowing, and displacing thewindpipe (trachea).
SYMPTOMSThyroid cancer usually begins as a smalllump (nodule) in the thyroid gland, whichis located at the center part of the front ofthe neck.While some small lumps may becancer, most thyroid nodules areharmless and are not cancerous.Most of the time, there are no othersymptoms.
Micrograph of papillary thyroid carcinoma demonstratingprominentpapillae with fibrovascular cores. H&E stain.
Micrograph showing that the papillae in papillary thyroidcarcinoma are composed of cuboidal cells. H&E stain.
Micrograph (high power view) showing nuclear changes inpapillary thyroid carcinoma (PTC), which include grooveformation, optical clearing, eosinophilic inclusions and
Treatment There are three types of thyroid cancer treatment: *Surgery *Radioactive iodine *Medication Surgery is done to remove as much of the cancer as possible. The bigger the lump, the more of the thyroid gland must be removed. Frequently, the entire gland is taken out. After the surgery, most patients should receive radioactive iodine, which is usually taken by mouth. This substance kills any remaining thyroid tissue. It also helps make medical images more clear, so doctors can see if there is any additional cancer. If surgery is not an option, external radiation therapy can be useful. After surgery or radioactive iodine, the patient will need to take medication called levothyroxine sodium for the rest of their life. This replaces the hormone that the thyroid would normally make
Other follow-upMost patients who had thyroid cancer needto a blood test every 6 - 12 months tocheck thyroid levels. Other follow-up teststhat may done after treatment for thyroidcancer include:Ultrasound of the thyroid done in the firstyearAn imaging test called a radioactive iodine
(PROGNOSIS)The survival rate for papillary thyroid cancer isexcellent. More than 95% of adults with such cancersurvive at least 10 years. The prognosis is better for patients younger than 40and for those with smaller tumors.The following factors may decrease the survival rate:*Age over 45*Cancer has spread to distant parts of the body*Cancer has spread to soft tissue*Large tumor