BackgroundThe cervical cancer screening recommendation for transgender female‐to‐male (FTM) patients is the same as that for cisgender females. A lack of literature on testosterone‐induced changes in cervical cytology in these patients may result in interpretation errors, especially without a proper clinical history. The aim of this study was to delineate the Papanicolaou (Pap) test findings in this patient population.MethodsA pathology laboratory information system was used to obtain a cohort of FTM transgender patients on testosterone therapy (2009‐2019). A cohort of age‐matched, atrophic, control cisgender female patients (postpartum or menopausal) was selected. A retrospective review of the cytomorphologic findings on cervical Pap smears, pertinent follow‐up, and human papillomavirus (HPV) test results was performed.ResultsFourteen transgender patients (age range, 21‐64 years; mean age, 42.5 years) receiving testosterone therapy with 17 Pap smears were identified. One of the 5 available HPV tests was positive for HPV, and 4 were negative. A Pap smear review revealed the following: negative for intraepithelial lesion (NILM; 82.4%), unsatisfactory (5.9%), atypical squamous cells of undetermined significance (ASCUS; 5.9%), and low‐grade squamous intraepithelial lesion (5.9%). The Pap smears of the atrophic cisgender cohort (102 patients) revealed the following: NILM (92.5%), unsatisfactory (0.9%), ASCUS (5.6%), and high‐grade squamous intraepithelial lesion (0.9%). The difference between the rates of epithelial cell abnormality in the 2 cohorts was not statistically significant. Although atrophy was noted in both groups, cytomorphologic findings of transitional cell metaplasia (TCM; 88.2%) and “small cells” (82.4%) were characteristic of the testosterone‐treated transgender cohort. Histologic correlates of TCM and small cells were noted in hysterectomy specimens from 6 patients.ConclusionsSmall cells and TCM are common cytomorphologic findings in Pap smears of testosterone‐treated transgender (FTM) patients. On the basis of histologic follow‐up, small cells most likely represent atrophic parabasal cells of cervical‐vaginal epithelium.