Stratified Mucin-Producing Intraepithelial Lesion of the Cervix: Subtle Features Not to Be Missed.

OBJECTIVES

Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant lesion of the uterine cervix. A detailed examination of preinvasive SMILE cases including a comparison of the cytologic features with usual-type adenocarcinoma in situ (AIS) and human papillomavirus (HPV) genotyping was performed.

STUDY

DESIGN

Excisions and preceding Papanicolaou (Pap) tests were retrieved from the files of 2 tertiary care centers. Histologic review estimated the lesional SMILE proportion. Pap tests were reviewed and assessed for architectural, cellular and background features. Cobas® HPV test was performed.

RESULTS

13 cases were identified. Mean/median patient age was 35/33 years (range 23-51 years). Concurrent high-grade squamous intraepithelial lesion was found in 10/13 (77%) and AIS in 8/13 (62%) cases. In 6 cases, SMILE was dominant (≥50%) and represented in 5/6 corresponding Pap tests. Cytology interpretations differed more often in the SMILE-dominant group (p < 0.05). SMILE and AIS had overlapping features. Feathering and prominent nucleoli were absent in SMILE. HPV DNA was detected in all 12 cases tested. HPV 18 was most common (7/12). Excisions with positive/suspicious margins were reported in 5/6 SMILE-dominant versus 3/7 nondominant cases.

CONCLUSION

SMILE is best considered as an AIS variant for cytologic, etiologic and management purposes. Cytologic features overlap with AIS, but are more subtle and easily missed. HPV testing may play a role in facilitating SMILE detection.