[400] So-Called 'Transitional Cell Metaplasia' of the Cervix and Vagina: A Cytologic Study

R Murali, NT Loughman, J Pagliuso, GF Watson, PR McKenzie, P Russell. Royal Prince Alfred Hospital, Sydney, Australia; Douglass Hanly Moir Pathology, Sydney, Australia

Background: So-called 'transitional cell metaplasia' (TCM) of the cervix and vaginal vault has been rarely described, and the cytologic features of only 9 cases of TCM have been reported. We sought to describe the clinical and cytologic features of cases of TCM, with particular reference to potential diagnostic pitfalls.
Design: Cervical and vaginal vault smears reported as TCM or smears from patients with histologically confirmed TCM were retrieved from the files of the Department of Anatomical Pathology, Royal Prince Alfred Hospital, Sydney. The following cytologic features were assessed: cellularity, architecture, cell group thickness, cell shape, nuclear:cytoplasmic ratio, nuclear features, perinuclear haloes and associated pathology. We compared the features of TCM with those of conventional atrophy, high grade squamous intraepithelial lesion (HSIL), reactive endocervical cells and tubal metaplasia.
Results: Six cases (five cervical, one vaginal vault) of TCM were identified from six patients (median age 60 years, range 34 to 80 years). Three patients were postmenopausal, one was perimenopausal, one was pregnant, and one had undergone female-to-male transgender reassignment. In all smears, three-dimensional cell groups in keeping with TCM were identified. They were multilayered and were composed of oval cells with increased nuclear:cytoplasmic ratio and spindle/oval shaped nuclei, with the impression of 'streaming' in some groups. The nuclei showed mild anisonucleosis, mild nuclear membrane irregularities, evenly distributed and variably granular chromatin, and small nucleoli. Nuclear grooves were identified in at least occasional cells in four cases. A surface layer of cuboidal cells was identified in two cases. The background contained associated dysplastic squamous cells (CIN 1 and CIN 2) in three cases, and these were conspicuously different from the cells comprising the TCM. Atrophic changes were present to varying degrees in all cases.
Conclusions: So-called TCM is seen in the setting of atrophy and some authors have suggested that it may represent an unusual morphological manifestation of atrophy. Its cytological differential diagnosis has been reported to include conventional atrophy, HSIL, and tubal metaplasia. In our experience, TCM shows a distinct set of cytologic features which enable its recognition and distinction from these entities.
Category: Cytopathology

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 36, Wednesday Morning