It is most common form of thyroid cancer and constitutes about 60 to 70 percent of the thyroid cancers. It constitutes 80% of thyroid cancers in children. Papillary carcinomas are unencapsulated tumors that tend to invade lymphatics and to spread to the normal surrounding thyroid tissue. Sometimes the tumor may contain localized deposits of calcium in connective tissue layers which are called psammoma bodies. Mixed carcinomas containing both papillary and follicular elements behave like the papillary carcinoma.

Multicentricity of the primary tumor is present. Lymph node metastasis is also quite early. A higher incidence of node involvement is found in children. This cancer is dependent on stimulation of thyroid stimulating hormone. The tremendous potentiality of this tumor to metastasize to regional lymph nodes while it is of microscopic size has given rise to the development of later aberrant thyroid.

It is the most slowly growing among the malignant tumors of the thyroid. Though it can occur at any age, yet the pick incidence is in the third and fourth decades. It occurs three times more frequently in females than in males. It shows a peculiar tendency to become more malignant with advancing age.

The lesion usually presents as an asymptomatic nodule within the thyroid gland. Pressure symptom, fixity of the thyroid lesion and distant metastases are all late in this condition. When the tumor is larger than 1.5 cm the chance of recurrence is more frequent and death from cancer occurs more often.

Investigations-

1.   Straight X-ray of neck- show calcium flecks suggesting psammoma bodies.

2.   Radioactive scan shows cold nodule.

3.   Ultrasound.

4.   Needle biopsy.

Treatment-

In majority of circumstances it is not possible to be definite about the diagnosis of this condition. The treatment of this condition is surgical excision. Due to multicentcity of this tumor, near total thyroidectomy is the treatment of choice.