Hodgkin Lymphoma
The most likely diagnosis is Hodgkin lymphoma (HL), given the widespread lymphadenopathy involving multiple nodal stations (mediastinal, retroperitoneal, mesenteric, axillary, and inguinal regions) combined with classic B symptoms of night sweats and weight loss. 1, 2
Clinical Reasoning
Key Diagnostic Features Present
Widespread lymphadenopathy: The CT demonstrates involvement of multiple lymph node stations across chest, abdomen, and pelvis—a pattern highly characteristic of lymphoma 1, 3
B symptoms: Night sweats and weight loss are classic constitutional symptoms that occur commonly in HL and indicate more advanced disease 1, 2
Nodal distribution: The involvement of mediastinal nodes (precarinal, paratracheal, AP window) is particularly characteristic of HL, as over 60% of HL patients present with enlarged cervical or mediastinal lymph nodes 2, 4
Size pattern: The lymph nodes measuring 10-11 mm are borderline enlarged but numerous, creating a pattern of multiple subcentimeter to low-centimeter nodes across multiple stations—consistent with lymphomatous involvement 3
Why Hodgkin Lymphoma is Most Likely
HL typically presents with painless lymphadenopathy and B symptoms, with mediastinal involvement being particularly common in young adults. 1, 2, 4 The bimodal age distribution peaks in the 20-40 year age group and again after age 55 1. The widespread nodal involvement spanning multiple anatomic regions (thorax, abdomen, pelvis) with constitutional symptoms strongly suggests lymphoma rather than reactive adenopathy 1, 4.
Differential Considerations
While non-Hodgkin lymphoma (NHL) remains in the differential, several features favor HL:
- Mediastinal predominance: The prominent mediastinal lymphadenopathy is more characteristic of HL than NHL 2, 5
- Pattern of spread: HL tends to spread in a more contiguous fashion through lymph node chains, whereas NHL may show more random distribution 3
- B symptoms: While present in both, B symptoms are particularly common in HL, occurring in the majority of patients with advanced disease 1
Important caveat: In immunocompromised patients (particularly those with HIV), HL presents with more advanced disease, extranodal involvement, and mixed cellularity or lymphocyte-depleted histologies, with 90% being EBV-associated 1. However, B symptoms in this population should always prompt investigation for opportunistic infections as well 1.
Mandatory Next Steps
The diagnosis of HL absolutely requires lymph node biopsy—this is non-negotiable. 1 An excisional lymph node biopsy or sufficiently large surgical specimen is preferred to provide adequate tissue for both fresh frozen and formalin-fixed samples 1.
Required Diagnostic Work-up
Excisional lymph node biopsy: Must obtain tissue showing Hodgkin-Reed-Sternberg (HRS) cells with characteristic immunophenotype (CD30+, CD15+, CD20-, CD45-) 1, 4
Complete staging evaluation once diagnosis confirmed 1:
Critical Pitfall to Avoid
Do not assume this is reactive lymphadenopathy or infection without tissue diagnosis. 6 While benign causes of lymphadenopathy exist (infectious mononucleosis, Kikuchi disease, IgG4-related disease), the combination of widespread nodal involvement with B symptoms mandates exclusion of malignancy 6. Non-malignant causes should be considered in the differential, but biopsy is essential 1, 6.
Staging Implications
Based on the widespread involvement (mediastinal, abdominal, and pelvic nodes), this patient would likely be classified as advanced stage (III or IV) by Ann Arbor/Cotswolds criteria 1. The presence of B symptoms further indicates unfavorable risk features 1. Treatment would typically involve combination chemotherapy with ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) for 6 cycles, with consideration for PET-guided therapy adjustments 1, 4.