WT1 in malignant melanoma

WT1 has been proposed as a complementary marker of malignant melanoma.

Benign naevocellular naevus

0/81

<10% of cells	11-50% of cells	51-75% of cells	> 75% of cells
19/272	4/272	2/272	2/272

Blue naevus

0/81

Spitz naevus

5/61

Dysplastic naevus / in situ melanoma

7/201

Epithelioid malignant melanoma

18/201

15/201

19/201

18/201

total

70/801

<10% of cells	11-50% of cells	51-75% of cells	> 75% of cells
11/492	8/492	5/492	25/492

Spindle cell / desmoplastic melanoma

11/111

Metastatic melanoma

18/201

Although Spitz naevi are commonly positive, positivity for WT1 may help in the diagnosis of malignancy. Junctional positivity may point to an adjacent invasive dermal component. It may help to differentiated melanoma from pre-existing naevus. Positivity in desmoplastic melanoma may be particularly helpful, as other markers apart from S-100 are usually negative: it may help to highlight neurotropism.

References

1 Wilsher M,Cheerala B. WT1 as a complementary marker of malignant melanoma: an immunohistochemical study of whole sections. Histopathology 2007; 51:605-10

2 Perry BN, Cohen C, Govindarajan B, et al. Wilms tumor 1 expression present in most melanomas but nearly absent in nevi. Arch Dermatol 2006; 142:1031-4 FULL TEXT

This page last revised 26.11.2007.