Ans. is 'a' i.e. Cold nodule on thyroid scan is diagnostic of malignancy On isotope scanning a thyroid nodule can be 'hot, 'warm' or 'cold'. Hot - a hot nodule is one that takes up isotope, while the surrounding thyroid tissue is inactive because the hot nodule is producing such high levels of thyroid hormones that TSH secretion is suppressed. Warm nodule - a warm nodule takes up isotope and so does normal thyroid tissue around it. Cold nodule - it takes up no isotope. The cold nodules carry a higher risk for malignancy. But a 'cold' nodule does not necessarily mean malignant. Only 20% of cold nodules turn out to be malignant, and about 5% of hot nodules can be malignant. Thus routine isotope scanning is no longer used to distinguish benign from malignant. FNAC is the investigation of choice for solitary thyroid nodule. The finding of a malignant diagnosis on FNAC is associated with a high accuracy rate (-100%), but false negative rate of FNAC is high (1-6%). Thus benign nodules should be kept under observation. An inconclusive FNA needs aggressive management. A repeat FNA is done. If still inconclusive, the pt. can be kept under observation if risk factors are low. Alternatively, if risk factors are high as in the present case, the pt. can undergo hemithyroidectomy to remove the nodule and sent for histopathology. Age and underlying medical condition are also taken into consideration while deciding course of management. About Indirect Laryngoscopy for assessment of mobility of vocal cords Recurrent laryngeal nerve and external laryngeal nerve are in close approximation to thyroid gland and liable to be injured during thyroid surgery. So preop assessment of mobility of vocal cords can be done as a routine protocol.