Hodgkin Lymphoma

Hodgkin Lymphoma

Todd M. Blodgett, MD

Alex Ryan, MD

Barry McCook, MD

Graphic demonstrates a typical appearance of Hodgkin lymphoma in the anterior mediastinum as a fairly homogeneous mass image, typically with low attenuation on CT.

Coronal PET (A), axial CT (B) and fused PET/CT (C) demonstrate an anterior mediastinal mass image with intense FDG activity, compatible with Hodgkin lymphoma.


Abbreviations and Synonyms

  • Hodgkin lymphoma (HL)

  • Hodgkin disease (HD)

  • Lymph nodes (LN)


  • Malignant neoplasm arising from lymphocytes

  • Rare variety is derived from histiocytes


General Features

  • Best diagnostic clue

    • FDG PET/CT

      • Enlarged FDG-avid lymph nodes/conglomerate mass

      • In usual location: Anterior mediastinum with other nodal groups

    • CT

      • Mediastinal lymphadenopathy presenting as mediastinal mass

      • ± Hepatomegaly, splenomegaly, lung nodules/infiltrates, pleural effusions

  • Location

    • Uncommon spread to extralymphatic locations

      • CNS, spine

    • Usual spread is to contiguous lymph nodes

      • Then to viscera or bone marrow

    • 30-40% of patients present with splenic involvement

    • 5-14% of patients have bone marrow involvement

    • Bone involvement

      • Primary bone invasion does not affect staging; rare (1-4%) at presentation

      • Hematogenous spread indicates stage IV disease

      • Stage IV occurs in 5-20% of patients during disease course

    • 6% of patients have chest wall involvement

      • Requires more aggressive therapy due to higher relapse rate

    • Thymic involvement considered “nodal”

      • Does not count as extranodal disease

      • Not associated with change in disease stage

      • Up to half of patients with thoracic HL may show enlarged thymus

      • Present after successful treatment as a result of rebound thymic hyperplasia

      • Occasionally develop thymic cysts

    • Rare locations

      • Peritoneal and omental involvement found only in non-Hodgkin lymphoma

      • Renal parenchyma is rarely involved, although perirenal space may be invaded

      • GI tract uncommon and usually due to nodal extension

  • Morphology

    • Rounded or bulky soft tissue mass due to nodal aggregation

    • Large masses may have areas of necrosis, hemorrhage, or cyst formation

Imaging Recommendations

  • Best imaging tool

    • PET/CT

      • Best for staging HD (sensitivity 94-98% and specificity 95-100%)

    • MR

      • To delineate soft tissue margins and evaluate spinal cord impingement

  • Protocol advice

    • Baseline FDG PET images should be obtained for initial staging

      • Prior to treatment

    • Patient should be kept warm and avoid activity prior to scan

      • Reduces physiologic uptake in muscle and fat

    • Low dose CT is acceptable for evaluating response to therapy

CT Findings

  • CT has replaced more complicated invasive diagnostic procedures

    • Method of choice for identification of disease invisible on clinical exam

    • Rarely performed anymore: Laparotomy/splenectomy, lymphangiography, and mediastinoscopy

  • Lymphadenopathy

    • Lymph node enlargement and aggregation

      • Appearance of multiple round or bulky soft tissue masses

    • Large masses may develop necrosis, hemorrhage, or cyst formation (10-20%)

    • Minimal contrast enhancement

    • Calcification rare before treatment but 20% prevalence post-radiotherapy

      • Rim calcification

      • Multiple discrete deposits (mulberry)

    • CT useful for treatment/radiation planning

  • Extralymphatic involvement

    • Mediastinal structures may show displacement, compression, or invasion

    • Cortical bone well evaluated with CT

    • Poor sensitivity for bone marrow disease

    • Invasion of gallbladder and pancreas usually from adjacent nodal disease

      • Absence of pancreatic capsule hinders diagnosis of invasion vs. contact

    • Thymic mass may be discrete or infiltrating

  • Therapy response

    • Tumor masses have low density of malignant cells

    • Reduction in volume of lesion is an insensitive predictor of response

Nuclear Medicine Findings

  • Initial diagnosis

    • Involved lymphoid tissue generally shows increased FDG uptake

      • No differentiation of subtypes by SUV has been demonstrated

    • Focal, super-physiologic uptake in nodal or extranodal tissue fairly specific indicator of disease

      • Diffuse uptake more difficult to interpret

      • Awareness of common FDG PET false positives is essential

    • Uptake may be seen in spleen and liver

      • Focal increased FDG activity generally indicative of malignant involvement

  • Staging

    • For organ staging, PET/CT seems to have no obvious advantage over FDG PET alone

      • Except in reducing false positives by better characterization of lesions using CT

    • Pooled true positive rate of FDG PET for HL: 90%

      • Upstaging rate: 8-25%

      • Shift to more advanced treatment: 10%

      • Downstaging: 2-23% (mean less than for upstaging)

      • FDG PET inclusion criteria are more accurate than CT inclusion criteria

      • Size is an insensitive indicator of malignancy

      • Enhancement characteristics are unreliable for inclusion

      • Combined PET/CT is superior for lesion delineation in radiotherapy planning

    • Bone marrow involvement

      • Diffuse marrow involvement may be intense

      • May also be indistinguishable from background

      • May be misinterpreted as negative for disease with diffuse marrow activity

      • Increased uptake can be iatrogenic

      • G-CSF, erythropoietin

      • Beta-thalassemia also increases uptake

      • Bone marrow biopsy (BMB) and PET/CT are complementary

      • Similar sensitivity/specificity but discordant findings

      • BMB more sensitive for detection of diffuse disease

      • PET/CT more likely to detect patchy disease

    • Spleen and liver

      • Full dose diagnostic CT necessary for adequate evaluation of liver and spleen

      • Splenic involvement may appear as diffusely increased uptake

      • Also seen in “reactive” spleen

      • Liver involvement may appear as diffuse uptake or patchy uptake in portal areas

      • Less commonly as large focal lesions

    • Response to therapy

    • SUV reduction of 60% is used as cutoff to separate treatment responders from nonresponders

    • PET has prognostic value after chemotherapy: 5 year survival after 2-3 cycles of chemo

      • 92% for PET-negative group

      • 39% for PET-positive group

    • 2 year progression-free survival after 2 cycles of ABVD-like chemo

      • 94% for PET-negative patients

      • 0-6% for early PET-positive patients

    • Study showed no evidence that patients benefit from treatment alteration based on early PET

      • Patients with PET-negative residual mass after chemo who received radiotherapy to original bulky site had 2.5% relapse rate within 18 months vs. 14% relapse in non-radiotherapy arm

      • In contrast, the International Prognostic Index (IPS) poorly predicts improved survival


Granulomatous Process

  • Active disease positive on FDG PET

  • Infectious and non-infectious etiologies

  • Will usually resolve over time

  • More likely bilateral hilar and paratracheal distribution


  • Pyogenic, fungal, parasitic, HIV-related, viral (e.g., varicella, zoster, HCV, CMV)

  • Usually positive on FDG PET

Other Malignancy

  • Variable enhancement and FDG uptake

  • History is crucial

Normal Lymphoid Tissue

  • Physiologic uptake common in Waldeyer ring, thymic tissue, cervical nodes

  • Asymmetric uptake can occur normally and may be mistaken for malignancy

Reactive Lymph Nodes

  • Usually much smaller than typical aggressive Hodgkin


General Features

  • Genetics

    • 1% of patients with HD have family history of disease

    • Sibling of affected individual has 3-7x increased risk

      • Higher in monozygotic twins

    • HLA-DP alleles more common in HD

  • Etiology

    • Unknown

    • Infection may be involved in pathogenesis, particularly Epstein-Barr virus (EBV)

      • Tumor cells are EBV-positive in ˜ 50% of HD cases

      • Positivity higher in MCHD (60-70%) than in NSHD (15-30%)

      • ˜ 100% of HIV-related HD are EBV-positive (though HD is not an AIDS-defining condition)

  • Epidemiology

    • 8,000 new cases and 1,000 deaths occur in the USA annually

    • Incidence: 3-4/100,000 per year

Gross Pathologic & Surgical Features

  • Cut surface white-gray and uniform

  • Affected LN

    • Usually enlarged

    • Shape is preserved

    • Capsule is not invaded

    • Surface may be nodular in nodular sclerosis subtype

Microscopic Features

  • Prominent lymphocytic infiltrate and Reed-Sternberg cells

    • Reed-Sternberg cells: Large, binucleate, with characteristic CD15+, CD30+ immunophenotype

  • Core biopsy preferred over fine needle aspiration

    • Malignant cells in HL make up only a very small, scattered proportion of the tumor volume

    • Subtyping requires core biopsy

    • Tumors pleomorphic

  • Bone marrow disease is often patchy and focal resulting in low sensitivity of bone marrow biopsy

    • If positive on PET, directed biopsy of that area increases true positive yield

Sep 22, 2016 | Posted by in MAGNETIC RESONANCE IMAGING | Comments Off on Hodgkin Lymphoma
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