Cytologic features of stratified mucin producing intraepithelial lesion of the cervix--a case report

Immunohistochemical and genetic characteristics of HPV-associated endocervical carcinoma with an invasive stratified mucin-producing carcinoma (ISMC) component

Invasive stratified mucin-producing carcinoma (ISMC) is a recently described entity of human papillomavirus (HPV)-associated endocervical adenocarcinoma with phenotypic plasticity and aggressive clinical behavior. To identify the cell of origin of ISMC, we investigated the immunohistochemical expression of cervical epithelial cell markers (CK7, PAX8, CK5/6, p63, and CK17), stemness markers (ALDH1 and Nanog), and epithelial-mesenchymal transition (EMT) markers (Snail, Twist, and E-cadherin) in 10 pure and mixed type ISMCs with at least 10% of ISMC component in the entire tumor, seven usual type endocervical adenocarcinomas (UEAs), and seven squamous cell carcinomas (SCCs). In addition, targeted sequencing was performed in 10 ISMCs. ISMC was significantly associated with larger tumor size (p = 0.011), more frequent lymphovascular invasion and lymph node metastasis (p < 0.001), higher FIGO stage (p = 0.022), and a tendency for worse clinical outcomes (p = 0.056) compared to other HPV-associated subtypes. ISMC showed negative or borderline positivity for PAX8, CK5/6, and p63, which were distinct from UEA and SCC (p < 0.01). Compared to UEA and SCC, ISMC showed higher expression for ALDH1 (p = 0.119 for UEA and p = 0.009 for SCC), Snail (p = 0.036), and Twist (p = 0.119), and tended to show decreased E-cadherin expression (p = 0.083). In next-generation sequencing analysis, ISMC exhibited frequent STK11, MET, FANCA, and PALB2 mutations compared to conventional cervical carcinomas, and genes related to EMT and stemness were frequently altered. EMT-prone and stemness characteristics and peripheral expression of reserve cell and EMT markers of ISMC suggest its cervical reserve cell origin. We recommend PAX8, CK5/6, and p63 as diagnostic triple biomarkers for ISMC. These findings highlight the distinct biological basis of ISMC.

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.

Detection of HPV RNA molecules in stratified mucin-producing intraepithelial lesion (SMILE) with concurrent cervical intraepithelial lesion: a case report

Background

Stratified mucin-producing intraepithelial lesion (SMILE) is a rare precursor lesion in the uterine cervix that is considered a variant of adenocarcinoma in situ (AIS). Although human papillomavirus (HPV) is thought to be related to the development of SMILE, there is little information available on the detection of HPV integrated into the lesion.

Case presentation

A 30-year-old female underwent a routine uterine cervical cancer screening, and her Pap smear indicated the possible existence of atypical glandular cells. A cervical biopsy with endocervical curettage was performed. The histopathological analysis showed that she had SMILE and high-grade squamous intraepithelial lesion (HSIL) on her cervix. The lesion was found to be positive for HPV genotypes 52 and 68 by multiplex PCR. In situ hybridization with HPV RNA probes revealed that these HPV types were involved in the onset of HSIL and SMILE, respectively.

Conclusions

Rare, high-risk HPV genotypes may contribute to the development of SMILE, and their detection can be useful for preventing the progression to carcinoma and ensuring adequate patient management.

Cervical Adenocarcinomas: A Heterogeneous Group of Tumors With Variable Etiologies and Clinical Outcomes

Context.—

Cervical adenocarcinomas are a heterogeneous group of tumors with varying morphologies, etiologies, molecular drivers, and prognoses, comprising approximately 25% of all cervical cancers. Unlike cervical squamous cell carcinoma, adenocarcinomas are not uniformly caused by high-risk human papillomavirus (HPV) infection and, therefore, would not necessarily be prevented by the HPV vaccine.

Objective.—

To provide a review of endocervical adenocarcinoma subtypes and, when appropriate, discuss precursor lesions, etiologies, molecular genetics, and ancillary studies within the context of clinical care. Some historical perspectives will also be provided.

Data Sources.—

Data sources included published peer-reviewed literature and personal experiences of the senior author.

Conclusions.—

Endocervical adenocarcinomas are a histologically diverse group of tumors with various causes and molecular drivers, not all related to HPV infection. Distinguishing them has important implications for treatment and prognosis as well as strategies for prevention.

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.

Invasive Stratified Mucin-producing Carcinoma and Stratified Mucin-producing Intraepithelial Lesion (SMILE): 15 Cases Presenting a Spectrum of Cervical Neoplasia With Description of a Distinctive Variant of Invasive Adenocarcinoma

Stratified mucin-producing intraepithelial lesion (SMILE) is a cervical intraepithelial lesion, distinct from conventional squamous or glandular counterparts, believed to arise from embryonic cells at the transformation zone by transdifferentiation during high-risk HPV-associated carcinogenesis. It is characterized by stratified, immature epithelial cells displaying varying quantities of intracytoplasmic mucin throughout the majority of the lesional epithelium. We identified a distinct form of invasive cervical carcinoma with morphologic features identical to those in SMILE, which we have termed "invasive stratified mucin-producing carcinoma." Fifteen cases from 15 patients (mean 36 y; range, 22 to 64 y) were retrieved from the pathology archives of multiple institutions with a diagnosis of either SMILE or invasive cervical carcinoma with a description or comment about the invasive tumor's resemblance to SMILE. Seven cases had solely intraepithelial disease with a component of SMILE (mean 29 y; range, 22 to 40 y). The 8 other cases had invasive stratified mucin-producing carcinoma (mean 44; range, 34 to 64 y) in which SMILE was identified in 7. All cases of invasive stratified mucin-producing carcinoma demonstrated stratified, immature nuclei with intracytoplasmic mucin, which morphologically varied between cases from "mucin-rich" to "mucin-poor" in a similar manner to SMILE. All cases had mitotic figures and apoptotic debris, and an intralesional neutrophilic infiltrate was seen in the majority of cases. In cases of invasive carcinoma, the depth of invasion ranged from <1 to 19 mm. Follow-up information was available in 8 cases and ranged from 1 to 36 months (mean 11 mo). Three cases of invasive stratified mucin-producing carcinoma had biopsy or resection-proven metastatic carcinoma on follow-up. These 15 cases of cervical stratified mucin-producing lesions show a combination of intraepithelial and invasive growth patterns. Given that SMILE is well rooted as a distinct intraepithelial lesion, we propose "invasive stratified mucin-producing carcinoma" to describe its corresponding form of invasive carcinoma.