Smooth Muscle Actin Immunostaining as a Marker of Invasion in Cervical Adenocarcinoma
VJA Panico, Y-F Liu, EC Pirog. Faculdade de Ciências Médicas de Santos - FCMS, Santos, SP, Brazil; Weill Medical College of Cornell University, New York, NY
Background: Differentiation of adenocarcinoma in-situ (AIS) from invasive adenocarcinoma (INV) of the cervix is difficult in some cases. Lack of objective markers of invasion may result in discrepant measurements of depth of invasion rendered by different pathologists. The goal of the study was to investigate if the expression of smooth muscle actin (SMA) in the cervical stromal cells surrounding invasive glands of adenocarcinoma may highlight the invasive foci and help to standardize the diagnosis.
Design: The study included cases of unequivocal invasive adenocarcinoma (n=21) as determined in a consensus review. The negative control group consisted of cases of unequivocal adenocarcinoma in-situ (n=9) and normal cervix (n=11). All cases were immunostained with smooth muscle actin antibodies (Dako).
Results: The stromal cells surrounding benign endocervical glands were negative for SMA staining in all of the normal cases; however, in 2 cases faint positive staining was identified surrounding deep Nabothian cysts. In addition, there was a positive reaction in the stroma of an endocervical polyp. In 6 of 9 cases of AIS the stromal SMA staining was negative, but in 3 cases focal faint positivity was identified. A strong stromal SMA positivity surrounding invasive tumor glands was present in 15 of 21 adenocarcinomas. In 11 cases the staining was seen throughout the entire tumor and in 4 cases the staining was present around majority of the glands. In 4 of 21 adenocarcinomas there was a marked inflammatory infiltrate surrounding the invasive glands and in these cases no SMA staining was identified in the stromal cells. Finally, two cases of adenocarcinoma had an exophytic growth pattern and these cases showed no stromal SMA staining in the papillary fibro-vascular cores.
Conclusions: Positive stromal SMA immunostaining may be useful to identify invasive glands in cervical adenocarcinoma, however, the staining may not be present in tumors surrounded by marked inflammation or in polypoid exophytic tumors.
Category: Gynecologic & Obstetrics
Tuesday, March 23, 2010 9:30 AM
Poster Session III # 183, Tuesday Morning