Is hysterectomy necessary for the treatment of preinvasive stratified mucin producing intraepithelial lesions of the cervix?

OBJECTIVES: Stratified mucin producing intraepithelial lesion (SMILE) is an uncommon premalignant cervical intraepithelial lesion, characterized by histopathologic features resembling those observed in high grade squamous intraepithelial lesions and adenocarcinoma in situ of the cervix. Its hybrid morphology poses a pathologic challenge with no specific management guidelines. The goal of this study was to review the natural history of SMILE and treatment based outcomes.

METHODS: A retrospective pathology review of all cases of cervical intraepithelial lesions, with confirmation of all SMILE lesions, at one institution between 2007 and 2019, was performed. Clinical and pathologic characteristics, management options, and patient outcomes were reviewed and analyzed. Inclusion criteria included all patients diagnosed initially with SMILE on biopsy, excisional procedure, or simple hysterectomy. Patients diagnosed with SMILE had to fulfill the following pathologic features: stratified columnar epithelium with nuclear atypia and mucin production throughout the epithelial thickness with increased mitotic activity, and/or apoptotic bodies. Pathologic slides were re-evaluated by a pathologist to confirm the diagnosis and review margin status.

RESULTS: 24 patients with SMILE were identified. Mean age at diagnosis was 36.2 years (range 25-53) with 67% (16/24) diagnosed before the age of 40. The majority (54%, 13/24) were nulliparous and 63% (15/24) had a past history of abnormal Pap smears. 92% (22/24) of patients were positive for high risk human papillomavirus, with 13% (n=3) presenting with a normal Pap smear. Diagnosis was made primarily on colposcopy (n=16), cold knife cone/loop electrosurgical excision procedure (n=7), or hysterectomy (n=1). Most patients (71%, 17/24) had a co-existing precancerous lesion at the time of diagnosis and the most common was high grade squamous intraepithelial lesion (53%). Five invasive lesions were also identified at the time of diagnosis of SMILE (2 adenocarcinoma, 3 adenosquamous), 1 of which underwent chemoradiation. Among all patients, 25% (6/24) underwent hysterectomy (4 simple, 2 radical), while 63% (17/24) of patients underwent a fertility sparing excisional procedure; 4% (1/24) were incidentally diagnosed on hysterectomy. 18 patients had negative margins and 2 patients had positive margins. Over a median follow-up of 29 months (range 3-105), all of the fertility sparing patients with negative margins had no recurrence. Among the two patients with positive margins, one had no recurrence on repeat excision and the other underwent repeat excision with persistent SMILE identified, subsequent negative margin, and no recurrence since.

DISCUSSION: Our data showed that most patients with SMILE were young, positive for high risk human papillomavirus, nulliparous, and presented with coexisting lesions. Excisional procedures with negative margins may be sufficient fertility sparing treatment in patients with preinvasive SMILE with a low risk of recurrence. There should be consideration of hysterectomy at the completion of childbearing.