[1087] Loss of Ciliated Cells Correlates with Tumor Progression in Ovarian Low-Grade Serous Carcinoma

Laura Ardighieri, Robert J Kurman, Ie-Ming Shih. Johns Hopkins University, Baltimore, MD

Background: Morphological and molecular studies have demonstrated that ovarian invasive LGSC develops from a non-invasive micropapillary serous carcinoma (MPSC), which develops in turn from an atypical proliferative (borderline) serous tumor (APST). Identification of morphological and molecular features associated with tumor progression in LGSC is fundamental in understanding the pathogenesis of this disease.
Design: Because ciliated cells are an integral component of APSTs, we hypothesized that the percentage of ciliated cells in different stages of tumor progression, i.e., APST, MPSC and LGSC may be reflective of this process. To facilitate the identification of ciliated cells, we performed immunohistochemistry to identify acetylated alpha-tubulin as ciliated cells are characterized by the presence of this protein. Paraffin tissues from a total of 45 serous ovarian tumors including 16 APSTs, 17 MPSCs and 12 LGSCs were analyzed and the percentage (%) of cells positive for acetylated alpha-tubulin determined.
Results: There was a progressive decrease of the percentage of acetylated alpha-tubulin positive ciliated cells from APST to MPSC then to LGSC. The average percentage of ciliated cells was 26.3 % in APSTs, 11.1% in MPSCs and 1.2% in LGSCs (p< 0.0001) (Figure 1). The four tumors that had concurrent APST and MPSC areas showed a decrease in the percentage of ciliated cells in the MPSC component (11.7%) as compared to the associated APST (28.0 %).
Conclusions: The findings in this study demonstrate a progressive loss of ciliated cells in the progression from APST to LGSC, and suggest that expansion of the non-ciliated cell population may be a prerequisite for malignant transformation. Additional studies are needed to investigate whether the percentage of immunohistochemically defined ciliated cells can be used as an adjunct in the differential diagnosis of different types of low-grade serous tumors.


Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 192, Tuesday Morning

 

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