Which of the following markers are seen in Primary effusion lymphoma?
**Core Concept**
Primary effusion lymphoma (PEL) is a rare and aggressive type of non-Hodgkin lymphoma characterized by its association with human herpesvirus 8 (HHV-8) infection. It typically presents as a lymphomatous effusion in the body cavities, such as pleural or peritoneal fluid accumulation, without any palpable lymphadenopathy or tumor mass.
**Why the Correct Answer is Right**
The correct answer is related to the unique immunophenotypic profile of PEL, which is distinct from other types of lymphomas. PEL cells are typically positive for **CD138** (also known as syndecan-1), a transmembrane glycoprotein involved in cell adhesion and signaling. This is due to the aberrant expression of **HHV-8**, which leads to the activation of signaling pathways that promote the expression of CD138.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because PEL cells are not typically positive for CD20, a B-cell surface antigen expressed in most B-cell lymphomas. CD20 is a useful marker for distinguishing B-cell lymphomas from other types of lymphoid neoplasms.
* **Option B:** This option is incorrect because PEL cells are not typically positive for CD30, a member of the tumor necrosis factor receptor family expressed in some types of lymphomas, such as anaplastic large cell lymphoma.
* **Option C:** This option is incorrect because PEL cells are not typically positive for CD15, a member of the selectin family expressed in some types of lymphomas, such as Hodgkin lymphoma.
**Clinical Pearl / High-Yield Fact**
Primary effusion lymphoma is a rare and aggressive type of non-Hodgkin lymphoma that is associated with human herpesvirus 8 (HHV-8) infection. It typically presents as a lymphomatous effusion in the body cavities, and the diagnosis is often made by detecting the presence of HHV-8 in the effusion fluid.
**Correct Answer:** A. CD138.