Thyroid gland cancer. Light micrograph of a section through a thyroid gland adenocarcinoma. The malignant (cancerous) tumour (neoplasm) arises from the lining (epithelium) of glandular tissue. The thyroid gland is situated in the neck, and controls the metabolic rate of the body. Adenocarcinoma cells have large amounts of cytoplasm. They have large, irregular, multi- nuclei (purple). Symptoms of thyroid cancer include difficulty in swallowing and possible loss of voice. Effective treatment involves the complete removal of the thyroid gland (thyroidectomy), followed by thyroid hormone replacement drugs. Magnification unknown.