Papillary Thyroid Carcinoma

Epidemiology

Papillary thyroid carcinoma is the most common thyroid neoplasm and accounts for 55 to 80% of all thyroid malignancies. Females are generally more commonly affected than males (2.5:1). The most common age at presentation is most often between 20 and 40 years. Papillary thyroid carcinoma has the highest incidence of cervical metastases among the thyroid malignancies. Almost 50% of cases have cervical nodal metastases at the time of presentation. It has been suggested that there is an increased incidence of papillary carcinoma in patients with Graves’ disease but this has not been proven definitively.

Clinical Findings

Patients generally present with an indolent, slowly growing, lower neck mass. Large masses can cause breathing or swallowing problems due to tracheal or esophageal compression. Pressure on the recurrent laryngeal nerve may cause hoarseness and aspiration secondary to vocal cord malfunction.

Pathology

On gross examination, the tumor may have a varied appearance and be solid or cystic. It can be encapsulated and well defined or infiltrative. Histological examination shows psammoma bodies, ground glass nuclei, and a branching pattern with a fibrovascular papillary stroma. When present, psammoma bodies are considered pathognomonic of papillary carcinoma of the thyroid. Histologically, they are seen as calcific concretions with well-defined concentric laminations that develop around a nidus of a necrotic cell. Follicular growth patterns may coexist with papillary thyroid carcinoma.

Treatment

Total thyroidectomy followed by iodine 131 radiotherapy is generally the treatment of choice. Lobectomy or subtotal thyroidectomy followed by suppression with thyroid stimulating hormone therapy is another accepted treatment option. Papillary carcinoma has the best prognosis among the cell types of thyroid malignancies.