Lymphnode metastasis is seen with
**Core Concept**
Lymph node metastasis is a critical process in cancer progression, where malignant cells spread from the primary tumor site to regional lymph nodes through lymphatic vessels. This process involves the invasion of cancer cells into the lymphatic system, their survival, and proliferation within the lymph nodes.
**Why the Correct Answer is Right**
The process of lymph node metastasis involves the disruption of the basement membrane of the lymphatic vessel by cancer cells, followed by their invasion into the lymph node through the afferent lymphatic vessels. Once inside the lymph node, cancer cells can survive and proliferate due to the presence of growth factors and cytokines that promote their growth. The lymph node's capsule and trabeculae also provide a suitable environment for cancer cells to adhere and proliferate.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a condition that is known to cause lymph node metastasis. While it is true that many cancers can metastasize to lymph nodes, this option is too vague and does not provide a clear answer.
**Clinical Pearl / High-Yield Fact**
One of the most common cancers that metastasize to lymph nodes is melanoma, which can spread to regional lymph nodes as early as 2 weeks after the initial tumor formation.
**Correct Answer:** D. Squamous cell carcinoma