Papillary Thyroid Cancer (PTC): Overview

Thyroid carcinoma comprises 1% of all malignancies but is the commonest malignant endocrine tumour. Annual incidence in the UK is reported at 2.3 per 100,000 women and 0.9 per 100,000 men (1).

Papillary thyroid carcinoma is the most common comprising 80% of all thyroid malignancies. It occurs in all age groups but is most common in the 3rd to 5th decades (2). Whilst, lymph node metastases are often present at diagnosis, haematogenous spread is a rare and late event. In contrast, distant metastases (commonly to bone and lung) are more common in follicular thyroid carcinoma, which represents approximately 10–20% of all thyroid cancers (2).

Distant metastases are noted in 1-3% of patients with thyroid cancer at initial diagnosis whereas 7-23% develop distant metastases during the course of the disease process (3). Commonly, thyroid carcinoma presents as a neck lump (which may be clinically solitary or multinodular) and initial presentation in the form of bone metastases leading to the diagnoses of thyroid carcinoma is rare.

Thyroid carcinoma is rare comprising 1% of all malignancies and commonly presents as a neck lump. Papillary thyroid carcinoma unlike follicular thyroid carcinoma tends not to metastasise to distant sites.

We present a case of papillary thyroid carcinoma presenting as a solitary asymptomatic pelvic bone metastases and highlight current management of bone metastases. A 59-year old female was found on abdominal computerised tomography to have an incidental finding of a 4.5 cm soft tissue mass in the right iliac bone. Biopsy of the lesion confirmed metastatic thyroid carcinoma. There was no history of a neck lump, head and neck examination was normal. Further imaging confirmed focal activity in the right lobe of the thyroid. A total thyroidectomy and level VI neck dissection was performed and histology confirmed follicular variant of papillary carcinoma.

Early detection of bone metastases have been shown to improve prognosis and thyroid carcinoma should be considered as a potential primary malignancy.

Papillary thyroid cancer is the most common type of thyroid cancer making up to 70-80% of all thyroid cancer cases. Papillary thyroid cancer can occur at any age, and its incidence has been increasing over the last few decades. There are about 20,000 new cases of papillary thyroid cancer in the United States each year. It is now ranked as the 8th most common cancer in women in the United States, and the most common cancer in women under the age of 25 years. Being diagnosed with papillary thyroid cancer can be very scary at first, however papillary thyroid cancers are most often slow growing tumors, and most can be removed surgically. Although slow-growing, papillary thyroid cancer can sometimes spread to the lymph nodes in the neck. Unlike some other tumors, positive lymph nodes do not usually worsen the generally excellent prognosis for. The involved lymph nodes can be surgically removed along with the thyroid. Most people diagnosed with PTC will not die from it.