[1111] Mesonephric Adenocarcinoma of the Uterine Cervix: An Update of the Immunohistochemical Profile.

Mohammad Othman, Elizabeth Euscher, Anais Malpica. MD Anderson Cancer Center, Houston, Tx

Background: Mesonephric adenocarcinoma (MA) is a rare subtype of uterine cervical carcinoma (CA).Secondary to overlapping histologic features with other subtypes of cervical CA (endometrioid and clear cell carcinoma), proper recognition can be challenging.Immunohistochemistry (IHC) is frequently utilized to assist with proper classification.It has been suggested that the use of PAX-2 may distinguish benign and mesonephric cervical lesions from cervical CA on the basis that PAX-2 was lost in usual type cervical CA.This study evaluates the expression of PAX-8 and PAX-2 as well as other traditional IHC in a series of MA.In situ hybridization (ISH) for high risk HPV is also evaluated.
Design: Six cases of MA were retrieved from our institutional files spanning 1991-2008. Pathology material was reviewed in all cases to confirm diagnosis.All cases were investigated by IHC for PAX2, PAX8, and p16. ISH for high risk HPV was performed on all cases.Previously performed IHC was also reviewed as part of the study.Clinical information was obtained from patients' (pts) charts.
Results: Pts ages ranged from 41-57 years (median 46).The most common presenting symptoms included: vaginal bleeding, 4 cases; menorrhagia, 1 case; and cervical polyp, 1 case. Five pts underwent hysterectomy; in cases where the stage was known (n=4), all were stage 1.Follow up ranging from 12 to 60 mos was available in 5 pts.All are currently free of disease.The immunoperoxidase results are summarized in table 1.

Summary of Immunoperoxidase Findings in MA
EMA (n=5)41
ER (n=3)21

For p16, 2 cases had patchy and 2 cases had focal staining.Staining for calretinin was focal in 2 cases and diffuse in 1.Vimentin staining was focal in 2 cases and diffuse in 3 cases.Staining for CEA was focal in the 2 positive cases. Staining for estrogen receptor was weak in the 2 positive cases.ISH for high risk HPV was negative in all 6 cases.
Conclusions: MA expresses both PAX-2 and PAX-8 suggesting that these markers could be useful to distinguish MA from usual types of cervical CA.The tendency of MA to express vimentin in conjunction with patchy or focal p16 can be misinterpreted as an indication of endometrial origin.In contrast to previous reports, the majority of the cases (66%) in this study were negative for CD10 and only 50% of cases were positive for calretinin.Therefore, these markers may have a limited role in the evaluation of MA.
Category: Gynecologic & Obstetrics

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 218, Tuesday Morning


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