General features
- HL represents approximately 30% of all lymphomas and has a bimodal age
curve with a peak at 15-35 years and a second peak over forties. EB virus is
probably involved in the pathogenesis, and progressively transformed
germinal centres are considered a precursor lesion of the nodular
lymphocyte predominant variant. Clinical signs, when present, are nocturnal
sweating, itch, fever, weakness, cough or the mediastinal syndrome if the
mediastinum is involved; corresponding patients are designed as B at the
staging, or A when lymph nodal enlargement only are present without
clinical signs. HL often arises in cervical lymph nodes and involves the
contiguous nodes. The mediastinum is involved mainly in nodular sclerosis
and the spleen in mixed cellularity.
- The lymph node architecture is effaced by a variable number of scattered
large mononucleated cells: Hodgkin cells (HC); lobulated mononucleated
cells: “popcorn cells” (L&H); and multinucleated cells: Reed-Sternberg cells
(HRS) in a background composed by a heterogeneous admixture of fibrous
stroma and non-neoplastic lymphoid cells, neutrophils and eosinophils.
Treatment of HL is based on clinical and pathological staging and prognosis
is excellent in most patients.
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Classification
The World Health Organization Classification of Lymphomas (2001)
HODGKIN LYMPHOMA (HODGKIN DISEASE) (WHO 2001)
- Nodular lymphocyte-predominant Hodgkin lymphoma
- Classical Hodgkin lymphoma
Nodular sclerosis classical Hodgkin lymphoma
Mixed cellularity classical Hodgkin lymphoma
Lymphocyte-rich classical Hodgkin lymphoma
Lymphocyte-depleted classical Hodgkin lymphoma
Power Doppler US pattern and FNC guide in Hodgkin lymphoma
Lymph nodes may be partially involved from HL. Power Doppler may reveal an abnormal vascular
pattern in a defined area of the lymph node that may be used as target in the FNC guide.
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FNC evaluation
Smears may be highly or scantily cellular; the patterns are variable
depending on the corresponding histotypes, the amount of fibrosis, and
the different cell composition in the different areas of the lymph node.
The general appearance of the smears is polymorphous with mature
lymphocytes and follicular centre cells, and a variable amount of
neutrophils and eosinophils. Epithelioid cells may also be present;
nuclear crushes and lymphoid tangles are expression of concomitant
fibrosis. The cytological diagnosis is made in the presence of HC and
RSL, which may be present in variable amounts and are generally
related to the corresponding histotypes: few in lymphocyte-rich and
nodular sclerosis, more in mixed cellularity and lymphocyte depletion. In
nodular lymphocyte-predominant Hodgkin lymphoma the diagnosis is
related to the identification of L&C in a lymphoid background. Diagnostic
cells are identified by ICC evidence of CD15 and CD30 positivity. ICC
evidence of CD20+ of L&H cell may be equivocal because large follicular
lymphoid cells may be CD20+ as well.
HODGKIN LYMPHOMA: diagnostic cells
RS cells with lobated nuclei, clumped chromatin and large nucleoli, CD30+.
Hodgkin cell in a polymorphus background with numerous eosinophils.
RS cells, CD15 and CD30 positives, with lobated nuclei, irregular chromatin and numerous
large nucleoli.
RS cells with lobated nuclei, clumped chromatin and large nucleoli, CD30+.
Mononucleated HC cells with irregular
chromatin and extremely large nucleoli.
CD15 and CD30 positive,
mononucleated HC cells.
A multinucleated cell with clumping chromatin
and hypercromasia. This cell may be
considered a “mummified” RSH cells.
A polyploid, multinucleated, nucleolated
RSH cells in a lymphoid background..
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Nodular lymphocyte predominant, Hodgkin lymphoma: Cytological findings
- Nodular lymphocyte-predominant Hodgkin lymphoma is characterized by a
diffuse lymphoid background with a variable number of large neoplastic
monucleated cells known as lymphocytic and/or histiocytic Reed-Sternberg
cell variants (L&H). The nuclei are often folded or multilobated, the
chromatin is mostly vesicular, the nucleoli are usually multiple and smaller
than those seen in classical HRS cells. Small lymphocytes, histiocytes and
some polyclonal plasma cells are present in the background.
- ICC: L&H cells: CD15-, CD30-, CD20+, CD79a+, BCL6+ and CD45+.
- FC: not contributive, CD4/CD8 co-expression has been reported.
Nodular lymphocyte predominant, Hodgkin lymphoma
Lymphocytic and/or histiocytic Reed-Sternberg cell variants (L&H). The nuclei may be round,
folded or multilobated, the chromatin is mostly vesicular, the nucleoli are usually multiple and
smaller than those seen in classical HRS cells. L&H cells are CD20+, CD15-,CD30-.
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Classical Hodgkin lymphoma: Cytological findings
Classical Hodgkin lymphoma: HRS cells are large and show abundant, slightly basophilic, cytoplasm and
two or more nuclear lobes or nuclei. Diagnostic RS cells have at least two nucleoli in two separate
nuclear lobes. Mononuclear variants are termed Hodgkin cells, and the cells represent only a minority of
the cellular infiltrate. The background is composed by reactive cellular infiltrate that varies according to
the histological subtype. HRS cells are positive for CD30 in nearly all cases, for CD15 in the majority of
cases and usually negative for CD45. Most HRS cells express the proliferation-associated nuclear antigen
Ki-67.
Classical Hodgkin lymphoma is classified as:
Nodular sclerosis, Lymphocyte-rich, Mixed cellularity and Lymphocyte-depleted
- Nodular sclerosis contains a variable number of HRS cells in a background of small lymphocytes and
other non-neoplastic inflammatory cells. Diagnostic cells may be rare or extremely numerous as in the
“syncitial” variant. The HRS cells of this subtype tend to have more lobated nuclei with smaller lobes, and
less prominent nucleoli. “Lacunar” HRS, determined by formalin fixation, which characterize this entity on
histological sections are not observed on the smears. Eosinophils may be numerous.
- Mixed cellularity HRS cells are typical; the background cells consist of a mixture of eosinophils,
neutrophils, histiocytes and plasma cells. One cell type may prevail over the others. The histiocytes may
show pronounced epithelioid differentiation and may form granuloma-like clusters.
- Lymphocyte-rich: scattered HRS cells in a background characterized by an abundance of small
lymphocytes. Eosinophils and neutrophils may be present in small numbers. The small lymphocytes may
be admixed with a large number of histiocytes with or without epithelioid features.
- Lymphocyte-depleted: rich in HRS cells and/or depleted in non-neoplastic lymphocytes. In some cases
pleomorphic HRS cells may predominate, producing a sarcomatous appearance.
- ICC: HC and HRS cells: CD15+, CD30+, CD20-, CD45-.
- DD: DLBCL: all types or metastasis in syncitial variant.
Classical Hodgkin lymphoma
HL: One RSH cell (lower left) and two HC
(center) in a lymphoid background.
HL: A CD 30 positive, RSH cell.
HL: One RSH cell (lower left) and two HC (upper
right) in an hematic and scantily lymphoid
background.
HL: one mirror cell and two, CD15 positive, HC.
HL: One HC with a large nucleolus in a
lymphoid background.
HL: RSH cells and numerous HC in a
lymphoid background. Two eosinophils are
present (lower left corner).
Extremely numerous and/or atypical RSH
cell in a background of granulocytes. This
picture may suggest a lymphocyte
depletion.
Extremely numerous CD30 positive
RSH cell may suggest a lymphocyte
depletion.
RSH cells in a necrotic and acute “inflammatory” background
Fibrosis fragments with intermingled
lymphiod cells and nuclear crushes may
be observed in HL smears.
More than occasional or numerous
eosinophils may suggest HL.
An atypical and ill-preserved
mononuclated cell in a back
ground of granulocytes and an
eosinophil. This image is
suspect for HL.
An atypical and illpreserved
multinucleated
cell suspected for RSH
cell.
An sole atypical binucleated
cell with large nucleoli
suspected for RSH cell.
An ill-preserved RS cell in a necrotic and
inflammatory background. This image is
suspect for HL.
A granulomatous pattern without a
consistent clinical context might hide a HL.
At the same time granulomatous pattern
may be observed in the follow-up of HL and
NHL.
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