Metastatic colorectal adenocarcinoma in cervicovaginal cytology specimens confirmed by immunocytochemical stains on liquid base specimens: Two study cases with review of the literature

Only a few cases of adenocarcinoma (ACA) metastatic to the female lower genital tract diagnosed on cervicovaginal Pap smear have been reported during the past several decades. Both conventional and liquid based cytology (LBC) have limited sensitivity and specificity in diagnosing metastatic disease and immunocytochemical (ICC) staining may be needed for confirming the diagnosis. We present two cases of metastatic colorectal ACA diagnosed on cervicovaginal ThinPrep (TP) Pap smears, with one confirmed by ICC staining method. Recognition of extra-uterine malignancy in the cervicovaginal cytology specimen is critical for the disease diagnosis, prognosis, and the treatment. ICC staining performed on the residual LBC specimen is an important methodology to confirm the diagnosis.