Transitional cell metaplasia of the cervix: a newly described entity in cervicovaginal smears.

Transitional cell metaplasia (TCM) of the cervix is rarely reported in the pathology literature. To our knowledge, no case reports describing TCM in cervicovaginal smears exist. We report the cytologic features of TCM and compare them with squamous-cell carcinoma in situ (CIS), tubal metaplasia (TM), and atrophy. One hundred twenty-seven cervicovaginal smears from 31 patients with histologically proven cervical TCM were reviewed: seven smears (five patients) showed TCM. Five smears each of CIS, TM, and atrophy were evaluated as to architecture, nuclear features, nuclear to cytoplasmic ratios, and cytoplasmic haloes for comparison to TCM. The features that characterize TCM and allow its distinction from CIS, TM, and atrophy include cohesive groups of streaming spindled nuclei with haloes, grooves, tapered ends, and wrinkled contours.