This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Which of the following helps in differentiation of follicular carcinoma from follicular adenoma of thyroid gland? \nSelect and explain. \nA. Hurthle cell change, B. Lining of tall columnar and cuboidal cells, C. Vascular invasion, D. Increased mitoses', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Robbins clearly write…. ‘Microscopically, most follicular carcinomas are composed of fairly uniform cells forming small follicles. Follicular carcinomas may be grossly infiltrative or minimally invasive. The latter are sharply demarcated lesions that may be impossible to distinguish from follicular adenomas on gross examination. This distinction requires extensive histologic sampling of the tumor-capsule-thyroid interface, to exclude capsular and/or vascular invasion. Extensive invasion of adjacent thyroid parenchyma makes the diagnosis of carcinoma obvious in some cases’.\nIdeal answer for a question for diagnosis of follicular cancer is capsular invasion\xa0(better than even vascular invasion) but in the given options, vascular invasion is the answer of choice.\nFollicular Carcinoma: brushing up key points\n\nIt is the 2nd most common form of thyroid cancer\nSeen in women of older age (40-50 yrs.)\nVascular invasion is common (less lymphatic spread) to bone, lung, liver etc.\nMicroscopically, there is presence of cells forming small follicles having colloid with NO Psammoma bodies. Uncommonly, cells have abundant, eosinophilic cytoplasm called as Hurthle cells\nDifferentiation from follicular adenoma is based on the presence of capsular invasion preferably and not on vascular invasion.', 'role': 'assistant'}]