Is a young adult patient with lymphadenopathy on both sides of the diaphragm and a groin lymph node with a fatty hilum still considered a classic presentation of Hodgkin lymphoma (HL)?

Presence of Fatty Hilum Does Not Exclude Classic Hodgkin Lymphoma Presentation

Yes, this remains a classic presentation of Hodgkin lymphoma despite the fatty hilum in the groin lymph node—the National Comprehensive Cancer Network explicitly states that a preserved fatty hilum should not be used as a definitive criterion to exclude Hodgkin lymphoma in young adults. 1

Key Diagnostic Principle

The presence of a fatty hilum is traditionally considered a reassuring feature suggesting benign lymphadenopathy in general radiology practice. However, this morphologic criterion has limited utility in excluding Hodgkin lymphoma, particularly in the young adult population where the disease is most prevalent. 1

Why This Remains Classic HL Presentation

Age and Distribution Pattern

• Young adults aged 15-34 years represent the highest incidence peak for Hodgkin lymphoma, with most patients diagnosed in their third decade of life. 1
• The patient's presentation with lymphadenopathy on both sides of the diaphragm (Stage III disease at minimum) is characteristic of the disease's contiguous spread pattern. 1, 2

Typical Spread Characteristics

• Hodgkin lymphoma characteristically spreads in an orderly, contiguous fashion from one lymph node group to adjacent groups, making bilateral involvement above and below the diaphragm a recognized presentation pattern. 1
• While isolated inguinal involvement would be atypical, inguinal nodes as part of disseminated disease with supradiaphragmatic involvement fits the expected progression. 1

Critical Diagnostic Approach

Required Workup

• Excisional lymph node biopsy remains mandatory for definitive diagnosis, providing sufficient tissue for both fresh frozen and formalin-fixed samples to identify Hodgkin and Reed-Sternberg cells with appropriate immunophenotyping (CD30+, CD15+, CD20 variable, CD45-). 3
• Comprehensive staging with contrast-enhanced CT of neck, chest, abdomen, and pelvis is essential to assess disease extent and identify bulky disease. 3, 1
• Baseline FDG-PET or PET-CT is strongly recommended as it provides functional information beyond anatomic imaging and has replaced bone marrow biopsy for staging in patients undergoing PET-CT evaluation. 3, 4

Common Pitfall to Avoid

Do not rely on radiologic features like fatty hilum to exclude lymphoma in young adults with concerning clinical presentations. The morphologic appearance of individual lymph nodes cannot override the clinical context of a young patient with bilateral lymphadenopathy and potential B symptoms. 1

Clinical Context Matters

Supporting Features

• More than 60% of Hodgkin lymphoma patients initially present with enlarged cervical lymph nodes, and mediastinal involvement is particularly common in the nodular sclerosis subtype that predominates in young adults. 3, 1
• The presence of B symptoms (fever, drenching night sweats, unexplained weight loss >10% over 6 months), fatigue, pruritus, or alcohol-induced pain should be documented, as these influence staging (A vs B designation) and prognosis. 3, 2

Prognostic Implications

• Stage III disease (lymph nodes on both sides of diaphragm) already places this patient in advanced-stage category, requiring longer courses of chemotherapy. 2, 5
• If extralymphatic organ involvement is confirmed, this would constitute Stage IV disease, which is specifically included in the International Prognostic Score as an adverse factor. 2

Bottom Line

The radiologic finding of a preserved fatty hilum in a groin lymph node should not provide false reassurance or delay appropriate diagnostic workup in a young adult with bilateral lymphadenopathy. Tissue diagnosis through excisional biopsy of the most accessible abnormal node remains the gold standard, and comprehensive staging with PET-CT will clarify the true extent of disease. 3, 1