Fabrizi Giujeppe, Pagliarello Calogero, Parente Paola, Massi Guido
Department of Dermatology, University of Molise School of Medicine - Via F. De Sanctis, 86100 Campobasso, Italy.
J Cutan Pathol. 2007 May;34(5):365-9. doi: 10.1111/j.1600-0560.2006.00622.x.
A few reports in the literature point out that in special areas of the body, nevi can have peculiar pseudomelanomatous features. In our routine work, we have met few examples of atypical nevi with peculiar features on the scalp of teenagers. To evaluate the frequency and the biological behaviour of these lesions, we have conducted a complete survey on melanocytic lesions on the scalp in a significant group of patients.
Thirty-nine nevi of the scalp were from adolescents (12-18 years), 160 from adults, and 30 from children below the age of 12 years.
About 10% of the melanocytic nevi of the scalp of adolescents have atypical cytological and architectural aspects that are different from those seen in Clark's dysplastic nevus. The most striking features were the presence of large bizarrely shaped nests scattered disorderly along the junction with follicular involvement. Other findings were pagetoid spread of cells above the junction and the discohesive pattern of the melanocytes in the nests. Mild cytological atypia was present but less significant. Such distinctive aspects are not found in nevi of the same site in adults or younger children. The general pattern of these atypical nevi of the scalp of adolescents closely recalls that of the so-called atypical nevi on special sites, i.e. nevi on mammary line, genitalia and body's folds. Despite the architectural and cytological atypia, clinical follow-up does not show any tendency to recur or proclivity to malignant behaviour.
Despite their similarities with melanoma, the nevi with atypical features of the scalp of adolescents are probably an entirely benign entity, at least at the moment of their excision. However, although benign, the relationship of this peculiar group of nevi with melanomas developed in adulthood remains entirely unknown, and the complete excision with conservative margins seems a recommendable procedure.
文献中的一些报道指出，在身体的特殊部位，痣可能具有特殊的假黑素瘤特征。在我们的日常工作中，我们遇到过少数青少年头皮上具有特殊特征的非典型痣病例。为了评估这些病变的发生率和生物学行为，我们对一大组患者的头皮黑素细胞病变进行了全面调查。
39例头皮痣来自青少年（12 - 18岁），160例来自成年人，30例来自12岁以下儿童。
青少年头皮黑素细胞痣中约10%具有非典型的细胞学和结构特征，与克拉克发育异常痣不同。最显著的特征是在与毛囊相连处有大的奇形怪状的巢状结构无序分布。其他发现包括交界处上方细胞的派杰样播散以及巢内黑素细胞的分离模式。存在轻度细胞学非典型性，但不太明显。在成年人或年幼儿童相同部位的痣中未发现此类独特特征。青少年头皮这些非典型痣的总体模式与所谓特殊部位的非典型痣，即乳线、生殖器和身体褶皱处的痣非常相似。尽管有结构和细胞学非典型性，但临床随访未显示任何复发倾向或恶变行为倾向。
尽管青少年头皮具有非典型特征的痣与黑色素瘤相似，但至少在切除时它们可能是完全良性的实体。然而，尽管是良性的，但这组特殊痣与成年后发生的黑色素瘤之间的关系仍然完全未知，以保守切缘完整切除似乎是一种可取的做法。
