**Core Concept**
Central nervous system (CNS) involvement in diffuse large B-cell lymphoma (DLBCL) is a rare but serious complication that requires prompt recognition and treatment. The CNS is protected by the blood-brain barrier (BBB), which limits the penetration of most lymphoma cells. However, certain types of DLBCL are more prone to CNS involvement due to their specific molecular characteristics and the presence of certain prognostic factors.

**Why the Correct Answer is Right**
CNS involvement in DLBCL is typically seen in patients with certain high-risk features, such as a high International Prognostic Index (IPI) score, a high lactate dehydrogenase (LDH) level, and the presence of certain molecular markers, including MYC rearrangements and BCL2 overexpression. Patients with these features are at a higher risk of developing CNS involvement, which can present as symptoms such as headaches, seizures, and altered mental status.

**Why Each Wrong Option is Incorrect**
**Option A:** While CNS involvement is not typically seen in this type of organ involvement, it is not entirely excluded. However, this option is not the best answer because it is a bit ambiguous.
**Option B:** This option is not the best answer because CNS involvement can occur in patients with this type of organ involvement, although it is less common.
**Option C:** While CNS involvement is more common in patients with certain high-risk features, it is not entirely excluded in patients with this type of organ involvement.

**Clinical Pearl / High-Yield Fact**
When evaluating patients with DLBCL, it is essential to assess for high-risk features, including a high IPI score, high LDH level, and the presence of certain molecular markers, as these patients are at a higher risk of developing CNS involvement.

**Correct Answer:** D