Aberrant nuclear beta-catenin expression in the spindle or corded cells in so-called corded and hyalinized endometrioid carcinomas. Another critical role of the unique morphological feature
Yoji Wani1, Makoto Saegusa2 and Kenji Notohara1
1Department of Pathology, Kurashiki Central Hospital, Japan and 2Department of Pathology, Kitasato University School of Medicine, Japan.
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Summary. Corded and hyalinized endometrioid carcinoma (CHEC), showing spindle and/or corded (SPICO) cells often in the background of hyalinized stroma, is a rare variant of uterine endometrioid carcinomas. The aim of our study was to explore the status of cell-adhesion molecules (beta-catenin, E-cadherin) in CHECs and to survey whether immunostains for beta-catenin and p53 can help to distinguish CHECs from their morphological mimics: malignant mixed mullerian tumors (MMMTs) and uterine tumors resembling ovarian sex-cord tumors (UTROSCTs). Immunohistochemistry was performed and scored for each element as follows: 0: negative, 1+: <10% positive cells, 2+: 10-30%, 3+: >30%. The SPICO patterns were classified as spindle/fusiform; 3, corded; 1, and both; 2. SPICO components consisted of <10%: 4, 10-30%: 1, >30%: 1. Five contained squamous components. In SPICO elements of all CHECs, nuclear beta-catenin expression (score: 1+; 1, 2+; 2, 3+; 3) and complete loss of membranous expression of E-cadherin was observed. In contrast, comparable components (sarcomatous ones for eight MMMTs or sex-cord-like ones for six UTROSCTs) showed no nuclear positivity for beta-catenin. p53 expression was observed in SPICO (64.7%), sarcomatous (87.5%), and sex-cord-like (50%) components, and sarcomatous areas of most MMMTs notably showed diffuse and intense staining. Sequence analysis of PCR amplification products of exon 3 of the beta-catenin gene revealed mutation in all cases, except two lacking SPICO components represented on microdissected areas. Our results suggest that alterations in beta-catenin/E-cadherin complex play a critical role in SPICO features. Immunostain for beta-catenin and p53 is a promising approach for distinguishing CHECs from MMMTs and UTROSCTs. Histol Histopathol 24, 149-155 (2009)
Key words: Endometrioid carcinoma, Sarcomatoid, Cord-like, Beta-catenin, Immunohistochemistry