Which of the following is not a type of peripheral T-cell neoplasm according to 2017 WHO classification?
**Core Concept**
The 2017 World Health Organization (WHO) classification of lymphoid neoplasms provides a standardized framework for the diagnosis and classification of lymphomas. Peripheral T-cell neoplasms are a group of malignancies that arise from T-cells in the peripheral blood, lymph nodes, and other tissues. These neoplasms can be further classified into various subtypes based on their histological, immunophenotypic, and genetic characteristics.
**Why the Correct Answer is Right**
The correct answer is a type of peripheral B-cell neoplasm, not a T-cell neoplasm. The 2017 WHO classification does not include this option as a subtype of peripheral T-cell neoplasm. The classification of lymphoid neoplasms is based on the cell of origin, and B-cell neoplasms are distinct from T-cell neoplasms in terms of their immunophenotype and genetic alterations. The correct answer is a B-cell neoplasm that is known to be a distinct entity in the 2017 WHO classification.
**Why Each Wrong Option is Incorrect**
**Option A:** This is a subtype of peripheral T-cell neoplasm according to the 2017 WHO classification, characterized by a distinctive immunophenotype and genetic alterations.
**Option B:** This is a subtype of peripheral T-cell neoplasm that is included in the 2017 WHO classification, known for its aggressive clinical behavior and poor prognosis.
**Option D:** This is a subtype of peripheral T-cell neoplasm that is recognized in the 2017 WHO classification, characterized by a specific genetic alteration and clinical presentation.
**Clinical Pearl / High-Yield Fact**
It is essential to note that the 2017 WHO classification of lymphoid neoplasms has replaced the previous classification, and it is crucial to be familiar with the new classification to accurately diagnose and classify lymphomas. The correct classification of lymphoid neoplasms has significant implications for treatment and prognosis.
**Correct Answer:** D.