Histological criteria for the diagnosis of small cell melanoma
| (1) | An obvious intraepidermal component recognisable at low power as in situ melanoma |
| (2) | An intradermal component composed entirely of small dark cells mimicking benign naevus cells, usually lying in tightly packed nests |
| (3) | The dermal nests composed of cells with hyperchromatic, slightly pleomorphic nuclei and scanty cytoplasm. There may be occasional prominent nucleoli |
| (4) | A stromal response of proliferation of small blood vessels between the dermal nests and a variable lymphocytic infiltrate |