Spitzoid malignant melanoma in teenagers: an entity with no better prognosis than that of other forms of melanoma
Aims: A rare form of melanoma in teenagers closely simulates Spitz naevus and is claimed to have a good prognosis. The aim of this study is to identify the clues for a confident diagnosis of this entity and to confirm the peculiarly good prognosis.
Methods and results: Two cases of melanoma with Spitzoid features were compared with Spitz naevus and it was found that the major distinctive criteria are: mitoses and single cell necrosis in the deepest part of the lesion, cellular and particularly nuclear and nucleolar pleomorphism, and growth pattern in solid sheets of cells. More subtle clues were the asymmetric distribution of pigment and the thinning of the epidermis with parakeratosis and exudate in the cornified layer. Both of the lesions reached the mid-dermis. There was a fatal outcome in both patients after generalized metastatic spread. The metastatic disease in one of the cases appeared 15 years after the excision of the primary lesion.
Conclusions: Spitzoid melanoma in teenagers can be distinguished from Spitz naevus if strict criteria are followed. Spitzoid melanoma does not show a better prognosis than other types of melanoma if the follow-up is prolonged enough.