A malignant thyroid tumour most commonly presents as a solitary nodule in one thyroid lobe or in the isthmus, often firm and indistinguishable from a colloid nodule or adenoma. The length of history is variable ΓÇô in some patients the swelling is first noticed by a relative, while in other cases patients have been aware of the lump in the neck for some years. There are usually no systemic symptoms.
Extrathyroid papillary carcinomas and angioinvasive follicular carcinomas present with more rapidly growing large tumours that may be associated with hoarseness, dysphagia, stridor, and dyspnoea.
Enlarged cervical lymph nodes due to secondary deposits are found in approximately fifty per cent of the cases of papillary carcinoma and much less often in follicular carcinomas.
