A 38-year-old woman from Mumbai presents with a 2-week history of rapidly enlarging left cervical lymphadenopathy, fever, night sweats, and a 4 kg weight loss. Excisional lymph node biopsy shows diffuse effacement of nodal architecture by large cells with abundant cytoplasm, prominent nucleoli, and frequent mitotic figures. Immunohistochemistry reveals CD20+, CD10+, BCL6+ B cells with a high Ki-67 proliferation index (>80%). Flow cytometry shows surface immunoglobulin light-chain restriction. A staging CT scan shows stage III disease with involvement of mediastinal, abdominal, and pelvic nodes. Serum LDH is 1,200 U/L (normal <400). What is the most appropriate next step in management?

Explanation

## Diagnosis: Diffuse Large B-Cell Lymphoma (DLBCL) This patient has **DLBCL**, the most common aggressive non-Hodgkin lymphoma in adults, characterized by: - Large cell morphology with high mitotic rate - CD20+, CD10+, BCL6+ immunophenotype (germinal center B-cell origin) - High Ki-67 (>80%) — indicates high proliferation - B symptoms (fever, night sweats, weight loss) - Advanced stage (III) with elevated LDH ## Why Immediate Chemotherapy Is Indicated **Key Point:** DLBCL is a **highly aggressive but potentially curable lymphoma**. Unlike indolent lymphomas, it requires urgent chemotherapy. Delaying treatment significantly worsens survival. **High-Yield:** Prognostic factors indicating poor prognosis and need for urgent therapy: 1. **B symptoms** — present (fever, night sweats, weight loss) 2. **Advanced stage** — stage III (extranodal involvement likely) 3. **Elevated LDH** — 1,200 U/L (>3× upper limit of normal) 4. **High Ki-67** — >80% (indicates aggressive biology) 5. **Age** — 38 years (relatively young, fit for intensive therapy) **International Prognostic Index (IPI) Score** for DLBCL: | Risk Factor | Points | |---|---| | Age > 60 years | 1 | | LDH elevated | 1 | | ECOG performance status ≥ 2 | 1 | | Stage III–IV | 1 | | Extranodal sites > 1 | 1 | This patient has **IPI score ≥ 3** (LDH elevated, stage III, likely extranodal involvement) → **high-risk disease** → requires immediate aggressive therapy. ## R-CHOP: Standard of Care **Mnemonic: R-CHOP** — **R**ituximab, **C**yclophosphamide, **H**ydroxydaunorubicin (doxorubicin), **O**ncovin (vincristine), **P**rednisone. - **Rituximab** — anti-CD20 monoclonal antibody; improves outcomes in CD20+ DLBCL - **Chemotherapy backbone** — CHOP remains standard despite newer regimens (R-EPOCH, R-CHOP with dose escalation) - **Cycles** — typically 6–8 cycles given every 21 days - **Cure rate** — 60–70% overall; higher in young, low-IPI patients **Clinical Pearl:** The addition of rituximab to CHOP improved 5-year overall survival from ~40% to ~60% in DLBCL. This is a landmark finding that transformed DLBCL management. ```mermaid flowchart TD A[Newly diagnosed DLBCL]:::outcome --> B{Fit for intensive therapy?}:::decision B -->|Yes| C[R-CHOP or R-EPOCH]:::action B -->|No| D[R-miniCHOP or clinical trial]:::action C --> E[6-8 cycles, q21 days]:::action E --> F{Complete remission?}:::decision F -->|Yes| G[Observation]:::outcome F -->|No| H[Salvage therapy ± ASCT]:::action ``` **Warning:** Observation or monotherapy in aggressive DLBCL is **not acceptable**. These are indications for immediate polychemotherapy. [cite:Robbins 10e Ch 20; Harrison 21e Ch 104]