This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid Malignancies, Subject name: Surgery
[{'content': 'FNAC can diagnose all of the following thyroid lesions except \nSelect and explain. \nA. Anaplastic carcinoma, B. Papillary carcinoma, C. Follicular carcinoma, D. Medullary carcinoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) Follicular carcinomaRef: Bailey & Love 24th/ 785y Schwartz 8th /1420* FNA biopsy is unable to distinguish benign follicular lesions from follicular carcinoma. Therefore, preoperative diagnosis of cancer is difficult unless distant metastases are present. Large follicular tumors (>4cm) in older men are more likely to be malignant. --Schwartz Surgery* FNAC is the investigation of choice for solitary thyroid nodules.* It cannot distinguish between a follicular Adenoma and a Follicular Carcinoma as this distinction is dependent not on cytology but on histological criteria such as capsular and vascular invasion. It therefore cannot be used to diagnose follicular carcinomas.', 'role': 'assistant'}]