Guidelines on Diagnosis and Treatment of Malignant Lymphomas

Primary Cutaneous
CD30-Positive T-Cell
Lymphoproliferative Disorders
Definition and Incidence
Primary cutaneous CD30+ T-cell lymphomas are the second
most common group of cutaneous T cell lymphomas, accounting
for 30% of cases. This group represents a spectrum of disease
with overlapping histopathologic and phenotypic features
including lymphomatoid papulosis, anaplastic large cell
lymphoma and borderline cases. The clinical appearance and
course are critical for definite diagnosis. Lymphomatoid papulosis
(LyP) is an indolent form characterised by recurrent crops of
self-healing papules and nodules, which may become necrotic
and usually resolve to leave varioliform scars. From a clinical
perspective LyP is not considered a malignancy, despite
monoclonality in many cases. Primary cutaneous CD30+
anaplastic large cell lymphoma (ALCL) is a T-cell lymphoma
presenting in the skin, and accounts for 25% of all cutaneous
T-cell lymphomas. The disease occurs almost exclusively in
adults and patients are mostly elderly. The male:female ratio
is approximately 2:1.
ICD-O Code 9718/3
rarely be involved in LyP. Duration of LyP may vary from months to
> 40 years. In up to 20% of patients LyP may be preceded by,
associated with, or followed by another type of lymphomas,
generally MF, cutaneous ALCL or Hodgkin lymphoma.
Pathology and Genetics
Histologically, lymphomatoid papulosis shows a wedge-shaped
polymorphic infiltrate consisting of atypical mononuclear cells with
cerebriform, anaplastic (CD30+) and pleomorphic cytology in a
background of smaller lymphocytes that may show
epidermotropism. There may be a marked inflammatory
background, If only sparse atypical lymphocytes are seen, it is
termed LyP type A, if there are sheets of atypical cells it is termed
LyP type C. In 80% of dermal infiltrate) represent
primary cutaneous ALCL. Infiltrates are diffuse and usually involve
both upper and deep dermis and subcutaneous tissue.
Clinical Presentation
In almost all instances the disease is confined to the skin at
diagnosis, with solitary or (less commonly) multicentric lesions,
which may be tumours, nodules or plaques. Extra-cutaneous
dissemination, mostly to local lymph nodes, may occur in ALCL.
LyP is characterized by the presence of papular, papulonecrotic
and/or nodular skin lesions at different stages of development.
Individual lesions disappear within 2-12 weeks. Oral mucosa can
Immunophenotype
The neoplastic cells express T-cell antigens, and are usually
CD4+. Most (>70%) of the cells express CD30. In LyP type B,
the lymphocytes are usually CD30 negative and CD3+, CD4+
CD8-. Rare cases of LyP and ALCL are CD8+. Cytotoxic granuleassociated
proteins (granzyme, perforin) are positive in 70%.
Aberrant T-cell phenotypes with variable loss of CD2, CD5, or
CD3 are common.
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