Definition
A rare CD8+ lymphoid proliferation localised to the skin of the external ear and showing indolent behaviour. It does not correspond to any of the entities in the WHO-EORTC classification.
This is a tumour of adults
The lesions are confined to the external ear and may be bilateral. They consist of pink or red nodules or plaques.
There is a dense diffuse dermal infiltrate of monomorphic medium-size lymphoid cells. Nuclei are irregular and nucleoli are small. The infiltrate is separated from the epidermis by a narrow Grenz zone. There may be neurotropism. There is no angiodestruction or necrosis. There are no neoplastic follicles. There are small aggregates of B-cells. Plasma cells, eosinophils and neutrophils are not a conspicuous feature.
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4/41 |
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0/41 |
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CD7 |
0/<41 |
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4/41 |
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0/41 |
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4/41 |
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0/<41 |
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0/41 |
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0/41 |
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positive in small lymphocytes1 |
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4/41 |
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beta-F1 |
4/41 |
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Granzyme B |
0/41 |
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0/41 |
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MIB-1 |
<10% of cells1 |
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There is a major T-cell g-gene rearrangement
CD4+/CD8- cutaneous T-cell lymphoma:
The provisional entity of CD8+ cutaneous T-cell lymphoma shows marked epidermotropism, ulceration, necrosis and an aggressive course.
Mycosis fungoides is rarely CD8+
Primary cutaneous CD30+ lymphoproliferative disorder may be CD8+
Pagetoid reticulosis is CD8+ in 50% of cases
subcutaneous panniculitis-like a/b T-cell lymphoma is usually CD8+
Peripheral T-cell lymphoma unspecified is CD8+ in 15% of cases; these are aggressive tumours.
Nasal-type T/NK-cell lymphoma is positive for Epstein-Barr virus
Cutaneous B-cell lymphomas may show symmetrical ear involvement
The course of disease is indolent. Relapses are confined to the ear.
©SMUHT/PW Bishop