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
Occult thyroid malignancy with nodal metastasis is seen in - 
Select and explain. 
A. Medullary carcinoma, B. Follicular ca, C. Papillary ca, D. Anaplastic ca
C: Papillary ca
Answer: C: Papillary ca 
Explanation: A small percentage of cancers present with enlarged lymph nodes in the jugular chain or pulmonary metastases with no palpable abnormality of the thyroid.
The primary tumor may be no more than a few millimetres in size and is termed occult. Such primary foci of papillary carcinoma may also be discovered in thyroid tissue resected for other reasons.
The term occult was formally applied to all papillary carcinomas less than 1.5 cm in diameter but the preferred terminology now is microcarcinoma for cancers less than 1 cm in diameter.
These have an excellent prognosis although those presenting with nodal or distant metastases justify more aggressive therapy". - Love & Bailey