A 35-year-old woman with biopsy-proven Hodgkin lymphoma (nodular sclerosis subtype) presents for staging workup. Physical examination reveals no hepatosplenomegaly. Which investigation is most appropriate to assess for occult abdominal and pelvic lymph node involvement and guide treatment planning?

Explanation

## Staging Investigation in Hodgkin Lymphoma **Key Point:** Contrast-enhanced CT (CECT) of the chest, abdomen, and pelvis is the standard imaging modality for staging Hodgkin lymphoma and detecting occult nodal and organ involvement. ### Why CECT is the Investigation of Choice 1. **Superior nodal assessment:** - Detects lymph nodes >1 cm short axis (size criterion for pathological involvement) - Evaluates mediastinal, hilar, abdominal, pelvic, and inguinal nodes - Assesses contiguity of disease (important for radiation planning) 2. **Organ involvement detection:** - Hepatic infiltration (nodular, diffuse, or miliary pattern) - Splenic involvement (focal lesions, diffuse infiltration, or splenomegaly) - Lung parenchymal disease (if mediastinal disease present) 3. **Treatment planning:** - Defines radiation field boundaries (involved-field radiotherapy) - Identifies sites requiring chemotherapy boost - Baseline for treatment response assessment **High-Yield:** CECT is **mandatory** for staging all patients with Hodgkin lymphoma. It is more sensitive than clinical examination (which misses ~20% of abdominal disease) and more practical than PET-CT for initial staging in most centers. ### Staging Investigations Hierarchy | Investigation | Indication | Role in HL | |---|---|---| | **CECT chest/abdomen/pelvis** | **All patients** | **Mandatory staging** | | PET-CT | Baseline + end-of-treatment response | Prognostic; increasingly used | | Abdominal ultrasound | Limited access to CT | Operator-dependent; lower sensitivity | | Bone marrow biopsy | Advanced stage (IIB, III, IV) | Assess marrow involvement | | Diagnostic laparotomy | Historical; now obsolete | Replaced by imaging + PET-CT | **Clinical Pearl:** In the modern era, diagnostic laparotomy with splenectomy is **no longer performed** for staging Hodgkin lymphoma. Non-invasive imaging (CT + PET-CT) has made it obsolete. Splenectomy carries morbidity (post-splenectomy sepsis risk) and does not change treatment in most cases. **Mnemonic — HL Staging:** **CAPET** = **C**T (mandatory), **A**bdominal assessment, **P**ET-CT (prognostic), **E**valuation of organs, **T**reatment planning.