What is the diagnosis and treatment for a patient with a neck mass, lymphadenopathy, night sweats, weight loss, HIV, and diabetes, with biopsy showing diffuse large B cells?

Diagnosis and Treatment of Diffuse Large B-Cell Lymphoma in an HIV-Positive Patient

This patient has Diffuse Large B-Cell Lymphoma (DLBCL), and should be treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy given every 21 days for 6-8 cycles, with careful attention to HIV status and CNS prophylaxis given the high-risk features. 1, 2

Diagnosis Confirmation

The biopsy findings of diffuse large B cells with irregular nuclei disrupting normal lymph node architecture is diagnostic of DLBCL. 1 Key diagnostic features include:

• Immunohistochemistry must confirm CD20 positivity (along with CD45 and CD3 as minimum panel) to ensure eligibility for rituximab-based therapy 1, 2
• The presence of HIV is particularly relevant as HIV-associated lymphomas can be more aggressive 1
• Additional markers (CD10, BCL-2, MUM1) can help determine germinal center vs. activated B-cell subtype, though this doesn't change initial treatment 1

Immediate Staging Workup Required

Before initiating treatment, complete the following staging evaluation:

• CT scan of chest, abdomen, and pelvis (already shows splenomegaly) 1, 2
• PET/CT scan is strongly recommended to better delineate disease extent and for future response assessment 1, 2
• Bone marrow aspirate and biopsy 1, 2
• Complete blood count, LDH, uric acid, comprehensive metabolic panel 1, 2
• Hepatitis B and C screening (in addition to known HIV status) 1, 2
• Cardiac function assessment (left ventricular ejection fraction) before anthracycline therapy 1, 2
• Calculate International Prognostic Index (IPI) and age-adjusted IPI for risk stratification 1, 2

Critical: CNS Prophylaxis Consideration

This patient requires CNS prophylaxis with intrathecal chemotherapy (cytarabine and/or methotrexate). 1 High-risk features present include:

• Multiple extranodal sites (cervical/supraclavicular lymph nodes plus splenomegaly) 1
• HIV-positive status increases CNS risk 1
• B symptoms (night sweats, weight loss) 1

Perform diagnostic lumbar puncture with simultaneous first prophylactic intrathecal instillation before starting systemic therapy 1

Standard Treatment Protocol

For this patient in their early 60s with DLBCL, the standard treatment is R-CHOP: 1, 2, 3

• Rituximab 375 mg/m² IV on Day 1 of each cycle 2, 3
• Cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) given every 21 days 1, 2
• Total of 6-8 cycles depending on response and tolerability 1, 2
• Rituximab is given for a total of 6-8 doses corresponding to chemotherapy cycles 2, 3

Critical Management Considerations

Tumor lysis syndrome prophylaxis is mandatory given the high tumor burden (multiple lymph node sites plus splenomegaly): 1, 2

• Consider corticosteroid pre-phase before full-dose chemotherapy 1, 2
• Aggressive hydration, allopurinol or rasburicase, and electrolyte monitoring 1, 2

HIV management during chemotherapy: 1

• Continue antiretroviral therapy throughout treatment
• Coordinate with infectious disease specialists
• Prophylactic antibiotics (PCP prophylaxis with trimethoprim-sulfamethoxazole) 1
• Use hematopoietic growth factors (G-CSF) prophylactically to prevent febrile neutropenia, especially critical in HIV-positive patients 1, 2

Diabetes management: 1

• Prednisone component of CHOP will significantly worsen glycemic control
• Aggressive glucose monitoring and insulin adjustment required during each cycle

Avoid These Common Pitfalls

• Never reduce chemotherapy doses for hematologic toxicity in patients treated with curative intent—use growth factors instead 1, 2
• Do not skip rituximab even in HIV-positive patients; CD20-positive DLBCL requires rituximab for optimal outcomes 2, 3
• Do not delay CNS prophylaxis—it must begin with or before systemic therapy in high-risk patients 1
• Hepatitis B reactivation screening is mandatory before rituximab administration, as reactivation can be fatal 3

Response Assessment

After 3-4 cycles, repeat imaging (CT or PET/CT) to assess response: 2

• PET/CT is highly recommended for accurate response evaluation 1, 2
• Complete the full 6-8 cycles if responding 1, 2

End-of-treatment evaluation: 2

• Repeat PET/CT scan to define complete remission 1, 2
• Repeat bone marrow biopsy only if initially involved 2

Prognosis and Risk Stratification

This patient has several adverse prognostic factors: 1, 2

• HIV-positive status
• Multiple extranodal sites
• B symptoms
• Splenomegaly
• Age >60 years

The IPI score will likely be intermediate-high or high risk (≥2), which typically indicates a more aggressive approach may be needed, though R-CHOP every 21 days remains the standard initial therapy. 1, 2 Approximately 60-70% of DLBCL patients achieve cure with R-CHOP, but HIV-positive patients may have slightly lower cure rates. 3, 4