CDX2 and LEF-1 expression in pilomatrical tumors and their utility in the diagnosis of pilomatrical carcinoma

Abstract

Background

The Wnt signaling pathway has been implicated in the pathogenesis of pilomatrical tumors. LEF-1 is a downstream component of this pathway, and CDX2 has been postulated to regulate it, but little is known about expression of these transcription factors in pilomatrical tumors.

Methods

Immunohistochemistry for CDX2, β-catenin, LEF-1, CK19, CK5, SATB2, Cadherin 17, and Androgen receptor was performed on pilomatricomas (PMs) (N=12), pilomatrical carcinomas (PMCAs) (N=12), and non-pilomatrical cutaneous tumors (N=18).

Results

PMs and PMCAs were positive for CDX2 (9/12 PMs, sens=75%,spec=100%;11/12 PMCAs, sens=92%,spec=100%;p<0.01), β-catenin (12/12 PMs, sens=100%, spec=94%;10/12 PMCAs, sens=83%, spec=94%;p<0.01), and LEF-1 (12/12 PMs, sens=100%, spec=56%;12/12 PMCAs, sens=100%, spec=56%;p<0.01 ). CDX2 expression was commonly focal, within a discrete subpopulation of squamoid cells. The LEF-1 expression pattern was different and discernable between pilomatrical tumors (strong, diffuse) and non-pilomatrical tumors (weak, patchy).

Conclusions

This study reaffirms the importance of the Wnt signaling pathway in the tumorigenesis of pilomatrical tumors, and introduces CDX2 as a possible regulator and marker of pilomatrical tumorigenesis. LEF-1 and CDX2 performed at least as well as β-catenin, if not better when taking into account expression pattern, as a diagnostic marker for pilomatrical carcinoma, and should be considered in the workup of ambiguous primitive-appearing cutaneous tumors.