男，9岁，左手背肿物2年。大体：皮下肿物，直径1cm，向表皮突起。切面灰白暗红色，实性，边界清楚，质硬。

Spitz痣首先考虑，局部还有点像副节瘤样。毕竟是个9岁的儿童，病变是皮肤表浅病变，而非深部组织，病变2年，恶黑、透明细胞肉瘤不大可能

支持Spitzs痣

 幼年性黑色素瘤。

 It seems this is a circumscribed proliferation of  epithelioid cells with adjacent epidermal hyperplasia. The cells are large with prominent nucleoli.  Mitotic figures are seen, although the depth of them is hard to evaluate in the pictures provided. Pagetoid spread and junctional involvement are not  prominent features of the lesion (please correct me if I'm wrong). I'm in agreement with others that it's prudent to decide the cell nature by immunohistochemistry. Melan-A, HMB45 and S100 can be considered as the first round to see if this is a melanocytic lesion.

If this is a melanocytic lesion, this lesion has concerning features of melanoma, including lack of maturation, atypical cytology, and increased mitotic activity. Given the absence of pagetoid spread and junctional involvement, Sptiz nevus is not a top differential diagnosis. Admittedly, the cells have spitzoid morphology.

Clear cell sarcoma of soft parts is positive for melanocytic markers. The histologic findings in this lesion do raise this possibility. But the superficial location and  the patient's young age are not typical for clear cell sarcoma of soft parts.  FISH study (t(12,22)) is of value in distinguishing this entity from melanoma.

Melanoma FISH study is utilized more and more frequently in diagnosing a tough melanocytic lesion, although its sensitivity and specificity are still subjects of research.

不典型增生Spitz痣，建议免疫组化（S-100、HMB45、Ki-67，CyclinD1和Bcl-2）等协助诊断

建议免疫组化（S-100、HMB45、Ki-67，CyclinD1和Bcl-2）等协助诊断。

同意

本例未见嗜上皮病变，亦未见kamino小体，Spitzs痣痣细胞应该更为梭形，本例细胞呈上皮样，大红核仁明显，另见少量花环状巨细胞，形态须除外透明细胞肉瘤

Spitz痣首先考虑

要做些免疫标记，黑素瘤，血管源性都要，谢谢

 关注

Spitz痣

 上皮样黑素细胞，核仁明显，可见少数核分裂，倾向于幼年性黑色素瘤考虑。

Spitz痣

图片所示以上皮样痣细胞为主，有异型性，支持Spitzs痣，能做个免疫组化最好。

支持