Which of the following is not a B-cell neoplasm?
**Core Concept**
A B-cell neoplasm is a type of cancer that arises from B lymphocytes, a subtype of white blood cells. These neoplasms can be classified based on their cell of origin, histological features, and clinical behavior. The most common B-cell neoplasms include lymphomas and leukemias.
**Why the Correct Answer is Right**
B-cell neoplasms include various types such as Chronic Lymphocytic Leukemia (CLL), Diffuse Large B-Cell Lymphoma (DLBCL), Follicular Lymphoma (FL), Mantle Cell Lymphoma (MCL), and Burkitt Lymphoma.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect - CLL is a type of B-cell neoplasm.
**Option B:** Incorrect - DLBCL is a type of B-cell neoplasm.
**Option C:** Incorrect - FL is a type of B-cell neoplasm.
**Option D:** Correct - T-cell neoplasms, such as T-cell Acute Lymphoblastic Leukemia (T-ALL) or Peripheral T-cell Lymphoma (PTCL), do not originate from B lymphocytes.
**Clinical Pearl / High-Yield Fact**
B-cell neoplasms can be distinguished from T-cell neoplasms based on their immunophenotypic characteristics, such as the expression of CD20 and CD19 on B cells. CLL, for example, typically expresses CD20 and CD19.
**Correct Answer:** D. T-cell neoplasms.