Though world over the age-standardised incidence of thyroid malignancies is around three in 100,000 population in males and 10 in 100,000 population in females proper diagnostic ultrasounds is needed to prevent the spread. Dr Harsh Dhar, Consultant and Head of Department, Department of Head Neck Oncosurgery, Medica Cancer Hospital, Kolkata reveals more
Malignancies of the thyroid are rare, however, recent years have seen an increase in the incidence, largely attributed to better diagnostic ultrasounds. World over the age-standardised incidence of thyroid malignancies is around three in 100,000 population in males and 10 in 100,000 population in females.
The commonest histology (pathological type) seen is Differentiated Papillary carcinoma, followed by Follicular carcinoma which constitutes 90-95 per cent of all thyroid cancers and bears an excellent prognosis. Other types seen are Medullary carcinoma (about 10 per cent of these are familial and bear a strong genetic predisposition) and Poorly Differentiated/ Anaplastic Carcinoma, which are aggressive varieties and tend to present in later stages.
Patients often notice a lump mostly in the lower anterior neck in the region of the thyroid gland, or in the lateral aspect of the neck (which may be due to spread to the lymph nodes). Many a time, it is not the patient, but a family member/friend who notices the lump first and it may be just a ullness in the region. These are rarely painful and do not cause any other symptoms in the initial stages. As the thyroid swelling increases, it may lead to compression of the surrounding vital structures and cause a change in voice, difficulty in swallowing and difficulty in breathing (due to compression or infiltration into the larynx or trachea) which is a medical emergency and needs a surgical intervention. Since these symptoms often manifest late, patients tend to neglect the initial swelling and often present in later stages.
In the event of distant metastasis, it may present in the form of bone pain, a lump on the scalp and even shortness of breath (in the case of lung metastasis). However, these form a minor subset of the entire pool. Initial diagnosis is through an ultrasound neck and guided fine needle cytology/ biopsy to ascertain the histology and further imaging – CT scan or MRI may be asked for, based on the size and extent of the tumour. A PET scan is rarely asked for, only in aggressive cases.
Surgical treatment in the form of hemi/total thyroidectomy is the mainstay and there are clear-cut guidelines with regards to the same. This may be accompanied by clearance of the neck nodes if indicated. Papillary and Follicular varieties also require Radio-iodine therapy for larger tumours in which a total thyroidectomy has been done. This therapy involves ingesting a radioisotope which homes in on the microscopic carcinoma cells and sterilises them to reduce the chances of recurrence.
Radioiodine therapy is also used for the treatment of distant metastasis. In select aggressive cases, external Radiation may also be used. With technological advancements, robotic thyroid surgery has now evolved which avoids a scar in the neck and surgery is performed through keyholes in the anterior chest or the axilla(armpit).
Thyroid malignancies overall have an excellent prognosis. Any lump in the neck should not be neglected and one should see an ENT/Head Neck Specialist at the earliest and get the necessary tests done, to ensure early diagnosis, early treatment and the best outcomes possible.
