**Core Concept**
Lymphomas are a group of cancers that arise from immune cells, specifically lymphocytes, which are an essential part of the body's immune system. The two main types of lymphomas are Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL).

**Why the Correct Answer is Right**
The correct answer will be the statement that is not true about lymphoma. Lymphomas are characterized by the uncontrolled growth of lymphocytes, which can accumulate in lymphoid tissues such as lymph nodes, spleen, and lymphoid organs. The two main types of lymphomas, HL and NHL, have distinct clinical and pathological features. HL is characterized by the presence of Reed-Sternberg cells, a type of abnormal lymphocyte, whereas NHL is a heterogeneous group of lymphomas that can be further categorized into subtypes based on the specific type of lymphocyte involved.

**Why Each Wrong Option is Incorrect**
**Option A:** This option may be a true statement, but it requires more context to determine its accuracy.
**Option B:** This option may be a false statement, but it is not clear without further information.
**Option C:** This option may be a true statement, but it is not necessarily incorrect.
**Option D:** This option is a false statement about lymphoma.

**Clinical Pearl / High-Yield Fact**
Lymphomas can be challenging to diagnose, and a thorough clinical evaluation, including imaging studies and biopsy, is essential for accurate diagnosis. The presence of lymphadenopathy (enlarged lymph nodes) is a common symptom of lymphoma, and a careful examination of the lymph nodes can provide valuable information for diagnosis.

**Correct Answer: D. Lymphomas are not caused by a viral infection.**