Case 23 Female, 38 years. Papule, skin of backShow diagnosis & comments
(Spitzoid) nodular melanoma
At low power, the lesion is more densely cellular and compact than usual Spitz naevi are. There is considerable mitotic activity at all levels of the lesion.
Since Spitz naevus resembles melanoma more closely than other naevus types (Dr Sophie Spitz originally considered them to be melanomas that, for some reason, did not manifest their malignant potential in children), it follows that melanomas not uncommonly resemble Spitz naevus. If the resemblance is striking, such melanomas are sometimes referred to as 'spitzoid melanomas'.
Since this resemblance is independent of other parameters that allow subtyping of melanoma, there are spitzoid superficial spreading melanomas, spitzoid nodular melanomas, etc. In adolescents and adults, the spitzoid appearance does not have a bearing on the melanoma in terms of biological behaviour.