Definition
A purely cutaneous T-cell lymphoma composed of CD30-positive anaplastic lymphoid cells. By definition, more that 75% of the tumour cells are CD30 positive.
Accounts for 25% of primary T-cell lymphomas of skin. It is a disease of adults, predominantly of the elderly.
Disease is limited to the skin at the time of diagnosis. Most cases show a solitary skin lesion or localised disease; in 20% it is multicentric. Lesions show regression, as for lymphomatoid papulosis, but relapses are frequent. Extension to regional lymph nodes occurs in 10% of cases, usually in association with multicentric disease.
Skin lesions may be tumours, which may ulcerate, nodules or papules.
The cytomorphology resembles that of ALCL, involving both superficial and deep dermis, often with extension into the subcutis1. Multinucleate and Reed-Sternberg-like cells are common. Epidermotropism is uncommon. An abundant inflammatory component is more typical of lymphomatoid papulosis.
Variants1
Classical, by far the most common. Most cells are large with abundant, often vacuolated cytoplasm and include bizarre forms, some resembling Reed-Sternberg cells (including lacunar variants, Hodgkin lymphoma-like variant). There is occasionally haemophagocytosis.
sarcomatoid variant in which there are pleomorphic spindle cells and a myxoid stroma. Reactive inflammatory cells may be abundant at the periphery of the lesion.
neutrophil-rich
eosinophil-rich
lymphohistiocytic
monomorphic variant; composed of a uniform population of centroblast-like cells. Nodal involvement is common.
small cell variant; commonly affect children. It may resemble tumour stage of mycosis fungoides, with numerous cerebriform T-cells and smaller numbers of anaplastic large cells and variable numbers of inflammatory cells.
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may be aberrantly negative1 |
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may be aberrantly negative1 |
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usually positive, occasional CD4-/CD8- cases are seen1 |
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may be aberrantly negative1 |
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usually negative1 |
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usually negative1 |
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usually positive1 |
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positive, in >75% of cells |
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CD71 |
usually positive1 |
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HLA-DR |
usually positive1 |
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granzyme B |
positive in 70% of cases |
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perforin |
positive in 70% of cases |
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positive in 70% of cases |
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HECA-452 |
positive in 50% of cases |
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negative |
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almost always negative1 |
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Cytogenetics
The translocation t(2;5)(p23;q35) commonly seen in systemic anaplastic large cell lymphoma shows is lacking in most primary C-ALCL.
Systemic anaplastic large cell lymphoma with cutaneous involvement: usually EMA positive, in contrast to primary C-ALCL. Also, systemic ALCL shows t(2;5)(p23;q35), which is lacking in C-ALCL
large cell transformation of mycosis fungoides
CD30 expression in other high grade lymphomas with cutaneous involvement.
Lymphomatoid papulosis; consider if there is a prominent inflammatory background
metastatic carcinoma or amelanotic melanoma.
sarcomatoid variant; myxoid MFH or other high grade sarcoma.
neutrophil-rich variant; pyoderma gangrenosum, panniculitis, infective dermatoses
The prognosis is good, with a 5 year survival of 90%. Spontaneous regression of skin lesions is associated with a better prognosis. Extracutaneous disease is associated with an inferior survival.
10-20% of cases of lymphomatoid papulosis show progression to lymphoma - variously mycosis fungoides, C-ALCL and Hodgkin lymphoma.
World Health Organization Classification of Tumours, Tumours of the haematopoietic and lymphoid tissues, IARC Press 2001.
This page last revised 23.12.2002.
©SMUHT/PW Bishop