Cytomorphologic alterations, histologic correlates, and clinical importance of pap test evaluation in intrauterine...

Cytomorphologic changes in intrauterine device (IUD) users are well described on conventional smear preparations, but studies regarding liquid-based cytology and by IUD type are limited. Therefore, this study aimed to characterize inflammatory, infectious, and epithelial alterations associated with IUDs with attention to specimen preparation method and device type.

The pathology information system of a large academic hospital was queried for Papanicolaou (Pap) tests from women with IUDs. Clinical, cytologic, and histologic features were reviewed and analyzed.

A total of 342 cases were identified. Squamous cell abnormalities were diagnosed in 36.8% of cases and glandular cell abnormalities in 1.8%. One adenocarcinoma presented diagnostic challenge due to IUD-related background changes. Characteristic epithelial alterations were common, including small dark cells (50.2%) and large vacuolated cells (48.9%). Background findings were dominated by acute inflammation (68%), whereas organisms were less common (Actinomyces species 15%, Candida species 9%). Pseudoactinomycotic radiate granules were common overall and differed significantly by liquid-based cytology preparation method (SurePath 57% versus ThinPrep 27%; P = 0.002). The only significant association with IUD type was a higher prevalence of bland endometrial cells observed in copper IUD users.

Small dark cells and vacuolated cells were consistently observed across specimen types, highlighting their importance as characteristic IUD-related changes. Differences between preparation techniques and device types were minimal but diagnostically important. Recognition of these IUD-associated alterations and subtle variations in preparation and IUD types is essential for accurate cytologic evaluation and appropriate patient management.