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: Surgery
[{'content': 'A 35-year old female presented with a swelling in the neck for the past 2 months, she had the treatment for Hodgkin’s lymphoma when she was 22 years with irradiation. On examination, her vitals were normal, there was a single, firm, irregular nodule, moving with deglutition in the left side of midline. Clinical examination also revealed a single node in the left side of the neck. The most likely clinical diagnosis of this condition is: \nSelect and explain. \nA. Recurrence of lymphoma, B. Malignant goiter, C. Benign multinodular goiter, D. Toxic nodular goiter', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Papillary Carcinoma of Thyroid:\n\nAccounts for 80% of all thyroid malignancies in iodine-sufficient areas.\nMC thyroid cancer in children and individuals exposed to external radiation.\nMore often in women, 30-40 years.\n\nPathology:\n\nGrossly: Hard and whitish and remain flat on sectioning with a blade with macroscopic calcification, necrosis, or cystic changes.\nMultifocality\xa0is common (up to 85% of cases) on microscopic examination.\nMultifocality is associated with an increased risk of cervical nodal metastases.\nRarely invade adjacent structures such as the trachea, esophagus, and RLN.\nRarely encapsulated\xa0(PCT are seldom encapsulated).\nOther variants: Tall cell, insular, columnar, diffuse sclerosing, clear cell, trabecular, and poorly differentiated types; account for about 1%; associated with a worse\xa0prognosis.\n\nHistological characteristics of Papillary Carcinoma Thyroid:\n\nPapillary projections: PTC contains branching papillae of cuboidal epithelial cells\nOrphan Annie eyed nuclei:\xa0The nuclei contain finely dispersed chromatin, which imparts an optically clear or empty appearance, giving rise to term ground glass or Orphan Annie eyed nuclei.\nInvaginations of cytoplasm in cross-sections: Intranuclear inclusions\xa0(pseudo-inclusion) or intranuclear grooves.\nDiagnosis of PTC is based on these nuclear characteristics\xa0even in the absence of papillary structures.\nPsammoma bodies: Microscopic, calcified deposits representing clumps of sloughed cells.\n\nClinical Features:\n\nMost patients are euthyroid and present with a slow-growing painless mass\xa0in the neck.\nDysphagia, dyspnea and dysphonia are associated with locally advanced invasive disease.\nLymph node metastases are common, especially in children and young adults, and may be the presenting complaint.\n“Lateral aberrant thyroid” almost always denotes a cervical lymph node that has been invaded by metastatic cancer.\nDistant metastases are uncommon at initial presentation, but may ultimately develop in up to 20% of patients.\nThe MC sites of metastasis: Lungs\xa0>bone >liver >brain.\n\nDiagnosis:\n\nDiagnosis is established by FNAC of the thyroid mass or lymph node.\nOnce thyroid cancer is diagnosed on FNAC, a complete neck ultrasound to evaluate the contralateral lobe and for LN metastases in the central and lateral neck compartments.\n\nTreatment: Total or near-total thyroidectomy\n\nDuring thyroidectomy, enlarged central neck nodes should be removed.\nBiopsy-proven lymph node metastases detected clinically or by imaging in the lateral neck in patients with papillary carcinoma are managed with modified radical neck dissection.\xa0\n\nPrognosis:\n\nPTC have an excellent prognosis with a >95% 10-year survival rate', 'role': 'assistant'}]