Mr. Ramu 30 years old male with papillary carcinoma in thyroid with a nodule < 3 cm confined to neck with 2 lymph node palpable in neck along with lung micro-metastasis. How will you stage this according to AJCC 8th edition?

**Core Concept**
The **American Joint Committee on Cancer (AJCC) 8th edition** staging system is used for classifying the extent of spread of cancer, including **papillary thyroid carcinoma**. This system helps determine the prognosis and treatment plan for patients.

**Why the Correct Answer is Right**
In the AJCC 8th edition, **papillary thyroid carcinoma** is staged based on the size of the primary tumor, presence of lymph node metastasis, and distant metastasis. For patients under 55 years old, the presence of distant metastasis categorizes the cancer as stage II, regardless of the size of the primary tumor or the number of lymph nodes involved.

**Why Each Wrong Option is Incorrect**
**Option A:** This option would be incorrect because it does not account for the lung micro-metastasis, which changes the staging.
**Option B:** This is also incorrect as the staging for papillary thyroid carcinoma under 55 with distant metastasis is not dependent on the size of the tumor or the number of lymph nodes.
**Option C:** Incorrect because the presence of lung micro-metastasis automatically categorizes this as a more advanced stage.

**Clinical Pearl / High-Yield Fact**
Remember, in the AJCC 8th edition, for **papillary thyroid carcinoma** in patients under 55, the presence of distant metastasis, such as lung micro-metastasis, automatically stages the disease as **stage II**, regardless of other factors.

**Correct Answer:** D. Stage II.