Histopathologic features of Spitzoid lesions in different age groups

Spitz nevus is one of the most difficult melanocytic lesions to diagnose in regard of malignancy, even for experienced dermatopathologists. We analyzed 28 tumors with Spitzoid morphology from 15 children (three little children 2-4-year-old, 12 peripubertary children 9-17-year-old) and 13 adults; there were 21 Spitz nevi, five atypical Spitz tumors and two Spitzoid melanomas in order to establish the diagnostic value of several morphologic parameters in different age groups. No significant differences in respect of age and/or tumor type occurred for gender, location, dimension, symmetry, sharp lateral demarcation, junctional nests orientation, adipose tissue extension, side-to-side cytologic symmetry, uniform melanin deposits, nuclear pleomorphism, presence of mitoses, inflammation and epidermal alterations. Pagetoid growth and/or melanin deposits in the keratin layer were significantly higher in little children. In adults, presence of isolated cells within the lateral margins allows differentiating Spitz nevus from atypical Spitz tumor and Spitzoid melanoma. Deep located mitoses were statistically associated with Spitzoid melanoma in adults. Ulceration was statistically more frequent in peripubertary patients than in adults, probably due to trauma. In conclusion, presence of worrisome morphologic features (pagetoid growth, isolated cells within the lateral margins or ulceration) is correlated to patient's age and less to tumor type; there is no unique morphologic feature to relay on when evaluating a Spitzoid tumor, the final diagnosis being the results of interpretation of multiple clinical, morphologic, immunohistochemical and molecular data and not least dermatopathologist's personal experience.