WT1 Immunoreactivity in Uterine Papillary Serous Carcinomas Is Different From Ovarian Serous Carcinomas

Abstract

WT1 diffusely stains most ovarian serous carcinomas; reactivity of uterine papillary serous carcinomas has not been evaluated. We studied WT1 expression in 13 International Federation of Gynecology and Obstetrics stage 1 and 5 stage 3 or 4 uterine papillary serous carcinomas without ovarian metastases and compared their reactivity with the WT1 staining of 30 ovarian serous carcinomas. WT1 reactivity was evaluated with the C19 and 6F-H2 antibody clones. All 18 uterine papillary serous carcinomas were nonreactive for WT1. The nonovarian metastases of the 5 high-stage uterine papillary serous carcinomas also were nonreactive for WT1. In contrast, 29 (97%) of 30 ovarian serous carcinomas were reactive for WT1. WT1 reactivity in an unknown primary serous carcinoma would suggest it is from a nonuterine site. The mechanisms underlying these findings are unknown. They raise the possibility of genetic differences between the 2 morphologically similar neoplasms.

The Wilms’ tumour suppressor Wt1 is a major regulator of tumour angiogenesis and progression

“…The intensity and frequency of WT1 expression in tumour vessels and stroma were homogenous in different samples and tumour types. Vascular and stromal WT1 were independent from WT1 expression in tumour cells 14,15 . WT1 was not expressed in healthy adjacent tissues, indicating that WT1 marks explicitly tumour vasculature and some stromal cells.…”

Data set for reporting of ovary, fallopian tube and primary peritoneal carcinoma: recommendations from the International Collaboration on Cancer Reporting (ICCR)

“…70,[123][124][125][126][127]149 Most tubo-ovarian serous carcinomas exhibit diffuse nuclear positivity with WT1, whereas most uterine serous carcinomas are negative. However, there is some overlap in that a proportion of uterine serous carcinomas are WT1 positive (the percentage has varied between studies) and a small percentage of tubo-ovarian HGSCs are WT1 negative.…”

“…However, there is some overlap in that a proportion of uterine serous carcinomas are WT1 positive (the percentage has varied between studies) and a small percentage of tubo-ovarian HGSCs are WT1 negative. 70,[123][124][125][126][127] It can be summarised that, although there is some overlap, diffuse WT1 positivity in a serous neoplasm favours a tubo-ovarian origin. In contrast, negative staining is a pointer towards a primary uterine neoplasm.…”

Selected other problematic testicular and paratesticular lesions: rete testis neoplasms and pseudotumors, mesothelial lesions and secondary tumors

“…These include mesothelioma-related markers (calretinin, WT-1, thrombomodulin, CK 5/6), 11,43 adenocarcinoma-related markers (CEA, Leu M1, B72.3, Ber EP4), 43 Wolffian-derived structures-associated markers (CD10, calretinin), Mü llerian papillary serous neoplasm-associated markers (WT-1, CA125); a sex-cord tumor-associated marker (inhibin), and markers useful in characterizing metastasis of unknown origin (prostate-specific antigen, prostate-specific acid phosphatase, CDX-2, TTF-1 and CK7/CK20 coexpression pattern). [44][45][46][47][48] Obviously, a judicious selection from the above comprehensive list is required based on the most likely differential diagnoses. Selected panels are summarized in Table 6.…”