Cytologic features of müllerian papilloma of the cervix: mimic of malignancy.

Müllerian papilloma is a rare benign tumor of the cervix and/or vagina that occurs predominantly in young children. The cytologic features of benign müllerian papilloma have never been described. We report for the first time, to our knowledge, the cytologic findings of a benign müllerian papilloma from the vaginal fluid specimen of a 15-mo-old girl using touch prep, ThinPrep, and cell block preparations. The deceptive cytologic features of a cellular specimen with complex papillary fronds composed of overlapping and crowded small hyperchromatic cells, with a high nuclear:cytoplasmic ratio, and feathering in this case resembled a malignant neoplasm. The clinical findings and cytomorphology of a benign müllerian papilloma can mimic those of malignant lesions of the female lower genital tract such as sarcoma botryoides and adenocarcinoma. An awareness of this entity and its potential to mimic these more aggressive neoplasms is essential for accurate diagnosis and to avoid over-treatment.