Polypoid Spitz naevus: the benign counterpart of polypoid malignant melanoma.
Polypoid malignant melanoma is a peculiar morphological variant of melanoma with a distinct exophytic pattern of growth. This form of melanoma is usually very thick and the prognosis is accordingly poor. We present here a previously undescribed form of Spitz naevus which had a similar polypoid exophytic silhouette and marked cytological atypia. Despite these close morphological similarities, polypoid Spitz naevus evolves in a completely benign manner. Morphologically, polypoid Spitz naevus can be distinguished from polypoid melanoma by the absence of mitoses and by the prominent stromal reaction throughout the lesion.
Fabrizi
G
G
Department of Dermatology, *Department of Pathology, Catholic University Medical School, Largo F. Vito, 1, 0168 Rome, Italy.
Massi
G
G
D000328:Adult; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology*; D018332:Nevus, Epithelioid and Spindle Cell / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*