Which one of the following variants of papillary carcinoma thyroid occurs in younger individuals including children with lymphonodal metastases in almost all cases and morphologically simulates Hashimoto thyroiditis is:
**Core Concept**
Papillary thyroid carcinoma (PTC) is a common type of thyroid cancer characterized by its papillary morphology and association with lymph node metastases. There are several variants of PTC, each with distinct clinical and pathological features.
**Why the Correct Answer is Right**
The variant of papillary carcinoma thyroid that occurs in younger individuals, including children, and is characterized by lymph node metastases in almost all cases is the **Warthin-like variant**. This variant morphologically simulates Hashimoto thyroiditis, a common autoimmune thyroiditis. The Warthin-like variant is known for its association with lymph node metastases, even in young patients, and its similarity in appearance to Hashimoto thyroiditis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is not a recognized variant of papillary carcinoma thyroid.
* **Option B:** While tall cell variant of PTC is a known variant, it does not typically present in young children and is not known for simulating Hashimoto thyroiditis.
* **Option D:** This option is not a recognized variant of papillary carcinoma thyroid.
**Clinical Pearl / High-Yield Fact**
The Warthin-like variant of papillary carcinoma thyroid is a rare variant that mimics Hashimoto thyroiditis histologically, but its aggressive behavior, including lymph node metastases, is a key distinguishing feature.
**Correct Answer:** C. Warthin-like variant of papillary carcinoma thyroid.