**Core Concept**
The spleen is an organ involved in the immune system and blood filtration, and various types of tumors can arise from its different cell components, including red pulp, white pulp, and the splenic capsule.

**Why the Correct Answer is Right**
The most common primary tumor of the spleen is a type of hematolymphoid neoplasm. Splenic marginal zone lymphoma (SMZL) is a rare type of non-Hodgkin lymphoma that originates in the marginal zone of the spleen, which is rich in lymphoid cells. This tumor type often presents with splenomegaly and can be associated with autoimmune cytopenias.

**Why Each Wrong Option is Incorrect**
**Option A:** While splenic metastases from other cancers (e.g., melanoma, lung cancer) can occur, they are not the most common tumors of the spleen.
**Option B:** Splenic sarcomas are rare and can be aggressive, but they are not the most common splenic tumors.
**Option C:** Splenic lymphoma is correct in that it is a type of lymphoma that can occur in the spleen, but SMZL is a more specific and accurate answer.

**Clinical Pearl / High-Yield Fact**
The spleen is involved in the immune response and can be affected by systemic diseases, such as systemic lupus erythematosus (SLE), which can increase the risk of developing splenic lymphoma.

**Correct Answer: C. Splenic marginal zone lymphoma (SMZL)**