Cervical Cytology of Stratified Mucin-Producing Intraepithelial Lesions
Zoltan Nagymanyoki, Tao Yang, Xiaohua Qian. Brigham and Women's Hospital, Boston, MA; Harvard Vanguard Medical Associates, Boston, MA
Background: Stratified mucin-producing intraepithelial lesion (SMILE) is a rare subtype of adenocarcinoma in situ (AIS) of the cervix. SMILE histologically resembles to a squamous intraepithelial lesion (SIL) but is characterized by stratified columnar neoplastic cells with diffuse intracellular mucin production (Figure 1). Neither the possibility of detection nor the cytologic features of SMILE have been previously reported.
Design: The files in two institutions were searched for any SMILE cases that had corresponding Pap tests within 12 months prior to histologic diagnosis. Pap test slides were reviewed and correlated to the histologic findings and clinical data.
Results: 12 cases of biopsy proven SMILE, occurring in women aged 22-41 (mean 30 years) with a total of 18 Pap tests were identified. Of the 18 Pap tests, reported diagnoses included 4 negative for intraepithelial lesion or malignancy (NILM), 5 atypical squamous cells of unknown significance (ASC-US) or atypical squamous cells, cannot exclude high grade SIL (ASC-H), 2 atypical glandular cells of unknown significance (AGUS), 2 LSIL, 1 HSIL, and 4 HSIL plus AGUS or AIS. In 2 of the AIS cases, SMILE was suggested. Upon retrospective review, atypical glandular cells, misinterpreted as reactive endocervical cells initially, were identified in all 4 NILM and 1 ASC-US (Figure 2). The 11 slides containing AGUS/AIS cells showed dark, crowded groups of cells with enlarged, round to irregular nuclei, course chromatin, inconspicuous nucleoli and moderate amounts of mucinous cytoplasm. Following the diagnosis of SMILE all patients underwent conization. In one case, invasive adenocarcinoma was also present on LEEP excision and hysterectomy was performed. In 7 of 12 cases, HSIL and/or AIS were also present.
Conclusions: SMILE is a diagnosis of relatively young women and it often coexists with significant lesions, such as HSIL, AIS and even invasive carcinoma. Although SMILE could be detected by Pap tests, it was only recognized as AGUS/AIS in 6 (33.3%), and correctly suggested in 2 (11%) cases. A substantial portion of cases were unrecognized. Awareness of this variant of AIS and its unusual cytomorphology on Pap test should be underscored.
Tuesday, March 5, 2013 8:45 AM
Proffered Papers: Section F, Tuesday Morning